Autonomic Nervous System - Apex

Question 1

Examples of positive feedback control in the human body include: (Select 3).:
a. generation of an AP
b. PaCO2 regulation
c. coagulation cascade
d. core temperature
e. serum glucose concentration
f. childbirth

Answer 1

A, F, and C

Question 2

Homeostasis is a steady-state condition that comes with a price - it requires ____ to maintain the system.

Answer 2

energy

Question 3

What does a negative feedback system dO?

Answer 3

Reverse a disturbance in some factors and leads to stability

Question 4

What does a positive feedback system do?

Answer 4

Enhances or accelerates a disturbance in some factors and usually leads to instability

Question 5

Any physiologic system that needs to be maintained in a normal range (set point) requires a ____.

Answer 5

control system

Question 6

What four things must a control system be able to do:

Answer 6

1. sense the regulated variable
2. compare the input signal with an internal reference/set point
3. Multiply the error signal by a proportionality coefficient (the gain) to produce an output signal
4. adjust the important factor by activating an effector system

Question 7

What is the most common control system for maintaining homeostasis?

Answer 7

A closed negative feedback loop

Question 8

What are the sensors for the regulated variable - PaCO2?

Answer 8

central chemoreceptors

Question 9

CO2 is hydrated in the ____, forming ____ which spontaneously dissociates into ___ and ___.

Answer 9

CSF; H2CO3; H+ and HCO3-

Question 10

The PaCO2 is directly reflected by the ____, which is detected by central chemoreceptors in the _____ of the _____.

Answer 10

H+; retrotrapezoid nucleus of the medulla

Question 11

What is the feedback controller for PaCO2?

Answer 11

Dorsal respiratory group (DRG)/central pattern generator (CPG)

Question 12

What are the effectors for the regulated variable - PaCO2?

Answer 12

muscles of inspiration

Question 13

An increased PaCO2 (the disturbance) results in a decreased PaCO2. What type of system is this?

Answer 13

A negative feedback control system

Question 14

What is the sensor for the regulated variable - cervical opening?

Answer 14

Stretch receptors in the cervix

Question 15

During L&D, sensory impulses from the stretch receptors in the cervix are sent to the _____.

Answer 15

hypothalamus

Question 16

What is the feedback controller for the regulated variable - cervical opening?

Answer 16

The periventricular and supraoptic nuclei of the hypothalamus

Question 17

Increased stretch impulses from the cervix received at the hypothalamus stimulate the _______ to release more _____.

Answer 17

posterior pituitary (neurohypophysis); oxytocin

Question 18

What are the effectors for the regulated variable - cervical opening?

Answer 18

Oxytocin and the myometrium

Question 19

Oxytocin binds to G protein-coupled receptors (Gq) on the _____, producing more ______.

Answer 19

myometrium; powerful uterine contractions

Question 20

The fetus pushing more forcefully against the cervix and stimulating more oxytocin release is an example of which type of system?

Answer 20

Positive feedback cycle system

Question 21

Oxytocin also stimulates _____ production by the uterine lining.

Answer 21

prostaglandin

Question 22

Negative feedback or positive feedback??

Control of serum sodium concentration

Answer 22

Negative feedback

Question 23

Negative feedback or positive feedback??

Enhances or accelerates a disturbance in a vital parameter

Answer 23

Positive feedback

Question 24

Negative feedback or positive feedback??

Propagation of an AP

Answer 24

Positive feedback

Question 25

Negative feedback or positive feedback??

Leads to stability in a vital parameter

Answer 25

Negative feedback

Question 26

Negative feedback or positive feedback??

Leads to instability in a vital parameter

Answer 26

Positive feedback

Question 27

Negative feedback or positive feedback??

Opposes or reverses a disturbance in a vital parameter

Answer 27

Negative feedback

Question 28

Which method of cell signaling occurs when a cell responds to a chemical signaling molecule that the cell itself produced and secreted?
a. endocrine signaling
b. paracrine signaling
c. neurotransmitter signaling
d. autocrine signaling

Answer 28

D - autocrine signaling

Question 29

What is the intracellular response to extracellular signals called?

Answer 29

Cell signaling/signal transduction

Question 30

The conversion of info into a chemical change is called _____, a universal property of living cells.

Answer 30

signal transduction

Question 31

Info arrives at cells in what 4 forms:

Answer 31

1. Purely physical (energy)
2. Chemical
3. Cellular
4. Extracellular matrix molecules

Question 32

What are examples of purely physical/energy forms?

Answer 32

light, sound, heat, pressure, electricity

Question 33

What are examples of chemicals?

Answer 33

NT, hormones, eicosanoids, drugs, toxins

Question 34

What are examples of a cellular form of information arriving at cells?

Answer 34

Gap junctions

Question 35

What are extracellular matrix molecule examples?

Answer 35

Collagen (think of PLT adhesion), integrins, laminin

Question 36

What are the 3 main methods of intracellular communication?

Answer 36

1. endocrine
2. paracrine
3. autocrine

Question 37

Endocrine cell signaling = _________

Answer 37

a signaling molecule (i.e., a hormone) is secreted by an endocrine cell and transported through the circulation where it acts on a distant target cell

Question 38

What is neuroendocrine signaling?

Answer 38

A specific type of endocrine signaling, where a neuron is the source of the hormone secreted into the blood

Question 39

What is an example of neuroendocrine signaling?

Answer 39

The adrenal medulla releases epinephrine that binds to B1 receptors on the heart

Question 40

What is paracrine signaling?

Answer 40

A chemical signaling molecule is released by one cell and acts locally to regulate the behavior of a neighboring cell

Question 41

_____ cell signaling is a specific form of paracrine signaling.

Answer 41

Neurotransmitter

Question 42

What is autocrine signaling?

Answer 42

A cell responds to a signaling molecule that it also produced.

Question 43

NE binding to a presynaptic A2 receptor on the same nerve terminal that released NE is an example of what type of signaling?

Answer 43

Autocrine

Question 44

What does autocoids mean?

Answer 44

Local hormone

Question 45

Where are autocoids and paracrine hormones produced?

Answer 45

Locally

Question 46

Autocoids and paracrine hormones are released in smaller or larger quantities than endocrine hormones?

Answer 46

Smaller

Question 47

T/F: Autocoids and paracrine hormones are intended to act locally and are metabolized locally.

Answer 47

True

Question 48

A chemical molecule that binds to a receptor and initiates a cellular response is called a:
a. second messenger
b. transducer
c. ligand
d. kinase

Answer 48

C - ligand

Question 49

What does signal transduction exhibit?

Answer 49

specificity and sensitivity
amplification
integration
feedback
compartmentalization
desensitization

Question 50

The flow of info in a signal transduction sequence follows _____ pathways.

Answer 50

Orderly

Question 51

What are the 6 processes in signal transduction sequences?

Answer 51

1. recognition
2. transduction
3. transmission
4. modulation
5. response
6. termination

Question 52

What are the 4 types of receptor-based signal transducers?

Answer 52

1. transmembrane G protein-coupled receptors (GPCR)
2. Transmembrane gated ion channels
3. transmembrane enzyme-linked receptors
4. Soluble nuclear (intracellular) receptors

Question 53

______ is imparted by the cell-specific receptor and is mediated by the same kinds of weak, non-covalent forces the mediate enzyme-substrate interactions.

Answer 53

Specificity (selectivity)

Question 54

Bonds ordered from weakest to strongest: ____ < _____ < ____ < ____ < _____

Answer 54

Van der Waals < hydrophobic < Hydrogen < ionic < covalent

Question 55

When does amplification by enzyme cascade result?

Answer 55

When an enzyme associated with a signal receptor is activated, and in turn catalyzes the activation of many molecules of a second enzyme, which activates a third enzyme, and so on

Question 56

What is integration?

Answer 56

The ability of a signal-transducing system to receive multiple signals and produce a unified response appropriate to the cell’s needs

Question 57

Multiple components of signaling pathways are often brought together on _____ to increase their local concentration and effects.

Answer 57

Scaffold proteins

Question 58

_____ are scaffolding proteins in addition to calcium channels.

Answer 58

Ryanodine receptors

Question 59

When does desensitization occur?

Answer 59

When a signal is present continuously, desensitization of the receptor system results. (when the stimulus falls below a certain threshold, the system again becomes sensitive)

Question 60

What is the general flow of info through G protein-coupled receptor signal transduction pathways?

Answer 60

1st messenger –> receptor –> effector –> 2nd messenger –> cellular response

Question 61

The 1st step of signaling sequences is ____.

Answer 61

recognition of the signal by its receptor

Question 62

All receptors are _____

Answer 62

proteins

Question 63

A general term for any chemical that binds to a receptor is what?

Answer 63

Ligand (note - ligand immediately implies that there’s a receptor involved)

Question 64

A ligand is also called what?

Answer 64

the first messenger

Question 65

What initiates the signaling sequence?

Answer 65

Energy from the stimulus-receptor interaction causes a conformational change in the receptor and then initiates the signaling sequence

Question 66

What is the second stage of the signaling sequence?

Answer 66

TRANSDUCTION of the extracellular message into an intracellular signal or 2nd messenger

Question 67

The conformational change of a receptor triggers either _____ or causes the receptor to _____.

Answer 67

catalytic activity intrinsic to the receptor; interact with membrane or cytoplasmic enzymes

Question 68

The final consequence of RECOGNITION + TRANSDUCTION is the generation of a _____ or the activation of a _____.

Answer 68

second messenger; catalytic cascade

Question 69

What messengers are extracellular signals?

Answer 69

1st

Question 70

What messengers are intracellular signals?

Answer 70

2nd

Question 71

_____ are extracellular signals, ____ are intracellular signals.

Answer 71

1st messengers; 2nd messengers

Question 72

What occurs are tranduction?

Answer 72

TRANSMISSION

Question 73

What is transmission during the signal sequence?

Answer 73

The second messenger’s signal to the appropriate effector(s)

Question 74

T/F: There are multiple pathways for signal transmission.

Answer 74

True

Question 75

What are some key activities in signal transmission pathways?

Answer 75

1. activation of kinases that add phosphates to proteins
2. release or sequestration of intracellular ions
3. regulation of metabolic processes

Question 76

____ and _____ typically occur during transmission

Answer 76

Amplification and integration

Question 77

What stage of the signaling sequence does amplification typically occur?

Answer 77

Transmission

Question 78

What stage of the signaling sequence does integration typically occur?

Answer 78

Transmission

Question 79

What occurs after transmission?

Answer 79

MODULATION of downstream chemicals

Question 80

What are two common modulation/”on/off” events?

Answer 80

enzymatic phosphorylation or dephosphorylation

Question 81

What occurs after modulation?

Answer 81

RESPONSE of the cell to the initial stimulus

Question 82

What are the different types of responses?

Answer 82

proliferation, differentiation, cell movement, metabolism, cell behavior

Question 83

What occurs after the response stage of the signal sequence?

Answer 83

TERMINATION of the response

Question 84

How is termination often accomplished?

Answer 84

feedback control

Question 85

What is ATP?

Answer 85

adenosine triphosphate

Question 86

What is IP3

Answer 86

Inositol triphosphate

Question 87

Phenylephrine is a ____ for the ____ receptor.

Answer 87

ligand/agonist/first messenger; alpha-1

Question 88

____ is a ligand for purinergic receptors.

Answer 88

ATP / adenosine

Question 89

What is an example of a drug that has an extracellular target?

Answer 89

Dabigatran

Question 90

What is an example of a drug that has an adhesion molecules?

Answer 90

Eptifibatide

Question 91

ID the 4 categories of receptor-based signal transducers.

Answer 91

1. G protein coupled receptors
2. Gated ion channels
3. Enzyme-linked receptors
4. Soluble nuclear receptors

Question 92

What is another name for a chemical that binds to a receptor?

Answer 92

ligand

Question 93

What family of enzymes catalyzes the addition of a phosphate group to a molecule?

Answer 93

Kinases

Question 94

What chemical messengers are derived from arachidonic acid? (select 3)
a. prostaglandins
b. thyroxine
c. aldosterone
d. leukotrienes
e. dopamine
f. anadamide

Answer 94

A - prostaglandins
D - leukotrienes
F - anandamide

Question 95

Most chemical signals fall into 4 categories of molecules:
1. ______
2. ______
3. ______
4. ______

Answer 95

1. small hydrophilic molecules
2. lipophilic molecules
3. peptides and proteins
4. others

Question 96

Where are small hydrophilic molecules, peptides, and protein messengers stored?

Answer 96

In vesicles inside the cells that synthesize these molecules

Question 97

______, _____, ____, and _____ are molecules that are not stored in vesicles.

Answer 97

Lipophilic molecules, purine, gas, and endocannabinoid messengers

Question 98

Chemical messenger molecules bind to either _____ receptors or ____ receptors.

Answer 98

cell-surface or intracellular (cytoplasmic or nuclear)

Question 99

What are the small hydrophilic chemical messenger classes?

Answer 99

Amino acids
BIogenic amines
choline esters
iodothyronines

Question 100

What are 4 examples of amino acids?

Answer 100

1. glycine
2. glutamate
3. GABA (y-aminobutyric acid)
4. aspartate

Question 101

What are 5 examples of biogenic amines?

Answer 101

1. dopamine
2. norepineprhine
3. epinephrine
4. serotonin (5-HT)
5. histamine

Question 102

What is an example of choline esters?

Answer 102

acetylcholine

Question 103

What are 2 examples of idothyronines?

Answer 103

1. thyroxine (T4)
2. triiodothyronine (T3)

Question 104

Small hydrophilic molecules are polar molecules are are ____ at physiologic pH.

Answer 104

ionized.

Question 105

Do small hydrophilic chemical messengers readily cross plasma membranes?

Answer 105

No - therefore needs cell-surface receptors

Question 106

____ of an amino acid precursor is a theme.

Answer 106

Decarboxylation

Question 107

What 4 things are derived from tyrosine?

Answer 107

1. dopamine
2. NE
3. Epi
4. iodothyronines

Question 108

T/F: GABA and glutamate can be intercoverted.

Answer 108

True

Question 109

How are small hydrophilic chemical messengers typically released?

Answer 109

exocytosis (exception is T3&T4)

Question 110

T3 and T4 are released through a ____

Answer 110

transporter

Question 111

What are the 3 types of lipophilic chemical messengers?

Answer 111

1. steroids
2. eicosanoids
3. miscellaneous

Question 112

Vitamin D3 and retinoids are _____ messengers.

Answer 112

Lipophilic (nonpolar)

Question 113

Prostaglandins are _____

Answer 113

eicosanoids

Question 114

Leukotrienes are _____

Answer 114

eicosanoids

Question 115

Thromboxanes are _____

Answer 115

Eicosanoids

Question 116

Steroids are derived from what?

Answer 116

cholesterol

Question 117

How do steroids circulate in the blood?

Answer 117

bound to a protein

Question 118

T/F: Steroids can diffuse through the lipid bilayer of plasma membranes.

Answer 118

True

Question 119

Where do steroids to receptors of target cells?

Answer 119

in the cytoplasm or nucleus of target cells

Question 120

What are eicosanoids derived from?

Answer 120

polyunsaturated fatty acids w/ 18, 20, and 22 carbons

Question 121

_______ is the main precursor of eicosanoids.

Answer 121

Arachidonic acid (20 carbons)

Question 122

Eicosanoids primarily have endocrine, autocrine, or paracrine actions?

Answer 122

autocrine and paracrine

Question 123

T/F: Unlike steroids, eicosanoids usually bind to cell surface receptors.

Answer 123

True

Question 124

What is calcitriol, 1,25-dihydroxycholecalciferol?

Answer 124

Vitamin D3

Question 125

What is 1,25(OH)2D3?

Answer 125

Vitamin D3

Question 126

______ is a cholesterol derivative but it does not retain the cholesterol ring structure.

Answer 126

Vitamin D3

Question 127

Do steroids retain the cholesterol ring strucutre?

Answer 127

Yes

Question 128

Retinoids are derived from what?

Answer 128

Vitamin A

Question 129

Retinoids play a role in ______.

Answer 129

growth and development

Question 130

Peptides and protein chemical messengers are generally ____ molecules.

Answer 130

hydrophilic (polar)

Question 131

Peptides and protein chemical messengers do or do not readily cross plasma membranes?

Answer 131

Do not

Question 132

How do peptides and protein chemical messengers circulate in the bloodstream?

Answer 132

As unbound molecules

Question 133

____ and _____ are nucleotides and nucleosides.

Answer 133

ATP and Adenosine

Question 134

Adeonsine and ATP are _____.

Answer 134

purines

Question 135

T/F: Adenosine and ATP are stored in vesicles.

Answer 135

False

Question 136

CO and NO are or are not lipid soluble?

Answer 136

Are

Question 137

What kind of action do CO and NO have?

Answer 137

paracrine

Question 138

What is NO synthesized from?

Answer 138

amino acid L-arginine

Question 139

NO and CO serve as ____ neurotransmitters.

Answer 139

Retrograde

Question 140

Anandamide (AEA) and 2-arachidonylgycerol (2-AG) are what type of chemical messengers?

Answer 140

Endocannabinoids

Question 141

What are endocannabinoids derived from?

Answer 141

arachidonic acid

Question 142

What receptors do endocannabinoids bind to?

Answer 142

CB-1 (CNS) and CB-2 (peripheral)

Question 143

Endocannabinoids are lipophilic or hydrophilic?

Answer 143

Lipophilic

Question 144

CB-1 and CB-2 are _____ receptors.

Answer 144

G protein-coupled

Question 145

The brain has more _____ receptors than any other type of G protein-coupled recetpor!

Answer 145

cannabinoid

Question 146

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Insulin - ___________

Answer 146

Peptide and protein molecules

Question 147

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

NO - ___________

Answer 147

Lipophilic

Question 148

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Angiotensin II - ___________

Answer 148

Peptide and protein

Question 149

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Thyroxine - ___________

Answer 149

Hydrophilic

Question 150

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Calcitriol - ___________

Answer 150

Lipophilic

Question 151

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Substance P - ___________

Answer 151

Peptide and protein

Question 152

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

GABA - ___________

Answer 152

Hydrophilic

Question 153

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Aldosterone - ___________

Answer 153

Lipophilic

Question 154

Small hydrophilic molecules, lipophilic molecules, or peptide and protein molecules???

Acetylcholine - ___________

Answer 154

Hydrophilic

Question 155

Which categories of signaling molecules are stored in vesicles in the cell that synthesized the molecules?

Answer 155

1. small hydrophilic chemical messengers
2. peptide and protein chemical messengeres

Question 156

Which lipophilic chemical messengers are not derived from cholesterol?

Answer 156

eicosanoids, retinoids, endocannabinoids

Question 157

Dopamine, Epi, NE, and the idothyroinines are derived from which amino acid?

Answer 157

Tyrosine

Question 158

How many times does a G protein-coupled receptor span the plasma membrane?

Answer 158

7

Question 159

What is the largest and most diverse family of receptors on the cell surface?

Answer 159

G protein coupled receptors (GPCR)

Question 160

What ligands bind to GPCRs?

Answer 160

NT, hormones, vasoactive peptides, odorants, tastants, and local chemical factors

Question 161

About ___ to ___ of all drugs target GPCR.

Answer 161

1/2 to 2/3

Question 162

G proteins are molecular switches and can _____ themselves through inherent GTPase activity in the ____ subunit.

Answer 162

inactivate; alpha

Question 163

In the GPT-loaded state, the ____ interacts with downstream effects. What may also interact with downstream effectors?

Answer 163

alpha subunit; beta-gamma complex

Question 164

What are the 4 G protein families?

Answer 164

1. Gs (stimulatory)
2. Gi (inhibitory)
3. Gq
4. G12,13

Question 165

What does the following represent?

Ligand –> GPCR –> Effector –> 2nd messenger –> Cell Resposne

Answer 165

The sequence of signal transduction through GPCR

Question 166

What 3 essential components characterize signal transduction through GPCRs?

Answer 166

1. plasma membrane receptor with 7 transmembrane helical segments
2. A guanosine nucleotide-binding protein (g protein) activates the effector enzyme/path
3. An effector (usually enzyme) generates 2nd messenger

Question 167

GPCRs have a plasma membrane receptor with _______ transmembrane ___ segments.

Answer 167

7; helical
(7-TM seven-helix or serpentine receptor)

Question 168

What do G proteins link?

Answer 168

receptor activation with a variety of downstream effects

Question 169

The ___ class of G proteins are associated with 7-TM receptors.

Answer 169

Heterotrimeric (αβᵞ subunits)

Question 170

When are G proteins turned ON?

Answer 170

when a ligand binds to the receptor binding site

Question 171

When are G proteins turned OFF?

Answer 171

By the intrinsic GTPase activity in the alpha subunit

Question 172

GDP is bound to the ____ subunit.

Answer 172

alpha

Question 173

When activated, the 𝜶βᵞ complex of GPRC disassembles into a free GTP bound ___ subunit and a separate ___ complex.

Answer 173

𝜶; βᵞ

Question 174

A _____ will stimulate (or inhibit) the production of a second messenger that will ultimately produce a change in cellular function.

Answer 174

G𝜶 subunit

Question 175

Major effector targets of G𝜶 subunits include: (3)

Answer 175

1. adenylate cyclases (AC)
2. Phospholipase C (PLC)
3. Phospholipase A2 (PLA2)

Question 176

T/F: The βᵞ complex can interact with down stream effectors.

Answer 176

True

Question 177

What are major effector targets for Gβᵞ subunits? (3)

Answer 177

1. Gi, 0-regulated potassium channels (GIRK)
2. voltage-gated calcium channels
3. beta-adrenergic receptor kinase (BARK)

Question 178

The alpha subunit has intrinsic GTPase activity, which catalyzes the hydrolysis of GTP to ___ and ___.

Answer 178

GDP and Pi

Question 179

Gs stimulates _____

Answer 179

adenylyl cyclase

Question 180

Gi inhibits ____

Answer 180

adenylyl cyclase

Question 181

Cq11 stimulates _____

Answer 181

phospholipase C (PLC)

Question 182

C12,13 activates ______

Answer 182

small G proteins

Question 183

____ toxin chemically alters the Gs subunit to inhibit the intrinsic GTPase activity.

Answer 183

Cholera

Question 184

Cholera inhibits the intrinsic GTPase activity. What occurs because of this?

Answer 184

continuous activation of the G protein and adenylate cylcase –> cell is swamped with cAMP –> stimulation of the export of fluid across the intestinal epithelium

Question 185

____ toxin chemically alters the Gi,0 subunit

Answer 185

Pertussis

Question 186

McCune-Albright syndrome is characterized by defects of ______.

Answer 186

hormonal regulation

Question 187

What causes McCune-Albright syndrome?

Answer 187

A gain-of-function mutation of Gs that correlates w/ a massive disturbance of Gs controlled. hormone production

Question 188

What causes pseudohypoparathyroidism?

Answer 188

A loss-of-function mutation of Gs (results in effects of PTH being suppressed –> premature puberty w/ obesity, growth retardation, and skeletal deformities)

Question 189

G-alpha subunit target effector OR G-beta/gamma subunit target effector???

Adenylyl cyclase

Answer 189

alpha

Question 190

G-alpha subunit target effector OR G-beta/gamma subunit target effector???

Phospholipase C

Answer 190

alpha

Question 191

G-alpha subunit target effector OR G-beta/gamma subunit target effector???

Voltage-gated Ca channels

Answer 191

beta/gamma

Question 192

G-alpha subunit target effector OR G-beta/gamma subunit target effector???

Gi,0-regulated potassium channels

Answer 192

beta/gamma

Question 193

G-alpha subunit target effector OR G-beta/gamma subunit target effector???

Phospholipase A2

Answer 193

alpha

Question 194

G-alpha subunit target effector OR G-beta/gamma subunit target effector???

Beta-adrenergic receptor kinase

Answer 194

beta/gamma

Question 195

Which heterotrimeric G-protein subunit contains the intrinsic GTPase activity?

Answer 195

alpha

Question 196

Match each enzyme with the substrate –> second messenger reaction the enzyme catalyzes.

Phospholipase A2, Adenylyl Cyclase, and Phospholipase C

ATP –> cAMP
PIP2 –> IP3 + DAG
Phospholipid –> arachidonic acid

Answer 196

Phospholipase A2 + Phospholipid –> arachidonic acid

Adenylyl Cyclase + ATP –> cAMP

Phospholiapse C + PIP2 –> IP3 + DAG

Question 197

GPCRs target what # of downstream effectors that produce second messengers?

Answer 197

3

Question 198

Adenylyl cyclase —> ___________

Answer 198

cyclic adenosine monophostate (cAMP)

Question 199

PHospholipase C (PLC) —> _________

Answer 199

inositol triphosphate (IP3) & diacylglycerol (DAG)

Question 200

Phospholipase A2 (PLA2) –> ________

Answer 200

Eicosanoids (20-carbon lipid mediators)

Question 201

T/F: Second messenger effects are tissue specific.

Answer 201

True

Question 202

Second messenger effects are ____ specific.

Answer 202

tissue

Question 203

____ plays a key role int he regulation of intracellular signal transduction.

Answer 203

cAMP

Question 204

The intracellular effects of cAMP are mediated by the enzyme _________, ____.

Answer 204

cAMP-dependent protein kinase, PKA

Question 205

_____ is a second messenger that leads to Ca2+ release from intracellular storage sites.

Answer 205

IP3 (inositol-1,4,5,-triphosphate)

Question 206

Many downstream signaling events mediated by Ca2+ are modulated by a Ca2+ sensing and binding protein, _____.

Answer 206

calmodulin (CaM)

Question 207

What is the function of adenylyl cyclase?

Answer 207

To convert ATP to cyclic adenosine monophosphate (cAMP)

Question 208

IP3 and DAG are ____ messengers

Answer 208

second

Question 209

___ together with ___ activates PLC

Answer 209

Gq,11 & Ca2+

Question 210

IP3 binds to what channels and where?

Answer 210

Ca2+ channels on the endoplasmic reticulum

Question 211

What is released after IP3 binds to a channel?

Answer 211

Calcium

Question 212

DAG in the membrane acts as a docking site for and activator of _____.

Answer 212

protein kinase C (PKC)

Question 213

Phospholipase A2 is a ___ dependent enzyme.

Answer 213

Ca2+

Question 214

Phospholipase A2 liberates what from the cell membrane?

Answer 214

Arachidonic acid

Question 215

Arachidonic acid is the precursor to how many families of lipid signaling. molecules?

Answer 215

3

Question 216

What 3 lipid signaling molecules is arachidonic acid the precursor to?

Answer 216

1. Prostaglandins and thromboxanes (porstanoids)
2. Leukotrienes
3. CYP450 monooxygenases

Question 217

CYP450 monoxygenases catalyze the formation of ____ and ____ from the ____ substrace.

Answer 217

HETEs (hydroxyeicosatetraenoic acid); EET (cis-epoxyeicosatrienoic acid); arachidonic acid

Question 218

Leukotrienes are generated when ___ encounters lipoxygenase.

Answer 218

arachidonic acid

Question 219

Prostaglandins and thromboxanes are produced by the initial action of ____ on the arachidonic acid substrate.

Answer 219

cyxlooxygenases

Question 220

Prostanoids, leukotrienes, HETEs, and EETs are collectively called _____.

Answer 220

Eicosanoids

Question 221

In cardiac myocytes, increased cAMP does what?

Answer 221

enhances contractiliy

Question 222

In cardiac myocytes, increased cAMP enhances contractility (____ receptors effects).

Answer 222

Beta-1

Question 223

_____ messenger effects are tissue-specific.

Answer 223

Second

Question 224

In smooth muscle of airways and vessels, increased cAMP causes _______.

Answer 224

relaxation and dilation.

Question 225

In smooth muscle of airways and vessels, increased cAMP causes relaxation and dilation (_____ receptor effects).

Answer 225

Beta-2

Question 226

In PLTs, increased cAMP _____.

Answer 226

reduces PLT aggregation

Question 227

In principal cells of the nephron, increased cAMP ___________________.

Answer 227

promotes insertion of aquaporin-2 water channels in the apical membrane

Question 228

Think of ____ as the sensors of second messengers.

Answer 228

protein kinases

Question 229

What are kinases?

Answer 229

Enzymes that catalyze the addition of phosphate groups (PO4 -2) to their substrate

Question 230

What are common tragets for kinases?

Answer 230

downstream proteins

Question 231

_____ catalyze the removal of phosphate groups from their substrate.

Answer 231

Phophatases

Question 232

cAMp activates ____ to modify cellular function.

Answer 232

protein kinase A (PKA)

Question 233

Protein Kinase A (PKA) contains 2 _____ and 2 _____.

Answer 233

regulatory subunits; catalytic subunits

Question 234

What happens when cAMP binds to the regulatory subunits of PKA?

Answer 234

It causes dissociation of the catalytic subunits

Question 235

What are the catalytic subunits of PKA?

Answer 235

Serine/threonin (Ser/Thr) kinases

Question 236

What terminates the action of cAMP?

Answer 236

Phosphodiesterases

Question 237

What terminates the action of protein kinases?

Answer 237

Protein phosphatases

Question 238

DAG is lipophilic or hydrophilic?

Answer 238

Lipophilic

Question 239

DAG and Ca2+ activate what?

Answer 239

Protein Kinase C (PKC)

Question 240

What cellular functions is PKC involved in? (its a lot….)

Answer 240

1. receptor desensitization
2. modulating membrane structure events
3. regulating transcription
4. mediating immune responses
5. regulating cell growth
6. learning and memory

Question 241

When is the action of DAG terminated?

Answer 241

When the molecule is recycled into new phospholipids

Question 242

IP3 is the ___ messenger that liberates ___ from intracellular storage sites.

Answer 242

second; Ca2+

Question 243

Ca2+ is released from ER into the ____, resulting in a dramatic increase in intracellular or extracellular Calcium?

Answer 243

cytoplasm; intracellular

Question 244

A high _____ activates several Ca2+ dependent protein kinases and phosphatases.

Answer 244

cytosolic [Ca2+]

Question 245

Ca2+ signals are terminated by ATP-dependent processes:
1. ______________________
2. _______________________

Answer 245

Ca2+ is returned into the ER
Ca2+ is pumped out of the cell

Question 246

When is the action of IP3 terminated?

Answer 246

when the molecule is recycled into new phophoslipids

Question 247

Freely available intracellular Ca2+ is a ____ messenger.

Answer 247

2nd

Question 248

_____ is directly or indirectly involved in most cell processes, from fertilization of the ovum to cell death.

Answer 248

Intracellular Ca2+

Question 249

Unlike other second messengers, ____ is NOT synthesized, liberated from a precursor molecule, or activated by enzymes.

Answer 249

Calcium (it is the increased intracellular Ca2+ that is the signal)

Question 250

What are the sources of Cytoplasmic Ca2+? (6)

Answer 250

1. voltage-gated Ca channels
2. storage- operated Ca channels
3. nonselective TRP ion channels
4. ionotropic NT receptors (NMDA)
5. IP3-controlled Ca channels (ER)
6. RyR Ca selective channels

Question 251

Downstream Target of Ca2+:

Voltage-gated calcium channels - _____

Answer 251

proteins that buffer calcium - calmodulin and calsequestrin

Question 252

Downstream Target of Ca2+:

storage-operated calcium channels - _____

Answer 252

Calcium sensor proteins (camodulin, troponin C, synaptotagmin [presynaptic vesicle exocytosis])

Question 253

Downstream Target of Ca2+:

Nonselective TRP ion channels - _____

Answer 253

enzymes (PLA2, PKC, NO synthases)

Question 254

Downstream Target of Ca2+:

Ionotropic NT receptors (NMDA) - _____

Answer 254

Receptors and ion channels: IP3 receptors, RyRs, Ca-activated K and Cl channels

Question 255

Removal of cytoplasmic reticulum….
voltage-gated calcium channels = _________

Answer 255

Na+-Ca2+ Exchanger (NCX) at the plasma membrane

Question 256

Removal of cytoplasmic reticulum….
storage-operated calcium channels = _________

Answer 256

Ca2+-ATPase (“pump”) at the plasma membrane (PMCA)

Question 257

Removal of cytoplasmic reticulum….
Nonselective TRP ion channels = _________

Answer 257

Ca2+-ATPase at the sarcoplasmic (muscle) or endoplasmic reticulum (SERCAs)

Question 258

What Ca2+ sending and binding protein modulates may downstream events mediated by Ca2+?

Answer 258

Calmodulin (CaM)

Question 259

When intracellular Ca2+ concentration increases, _____ Ca2+ binds to CaM inducing a major conformation change to the protein.

Answer 259

3-4

Question 260

The active Ca2+/CaM complex has a wide range of downstream targets including:
1.
2.
3.
4.

Answer 260

1. NO synthase
2. Ca2+/CaM dependent protein kinases (ex: myosin light-chain kinase)
3. adenylyl cyclase
4. cAMP-specific PDE

Question 261

caMP, DAG, IP3, or iCa???

Lipid second messenger

Answer 261

DAG

Question 262

caMP, DAG, IP3, or iCa???

Generated from PIP2 and stays in the plasma membrane

Answer 262

DAG

Question 263

caMP, DAG, IP3, or iCa???

Targets ligand activated Ca channels on the ER

Answer 263

IP3

Question 264

caMP, DAG, IP3, or iCa???

IP3 releases it from the ER

Answer 264

iCa

Question 265

caMP, DAG, IP3, or iCa???

Removed from the cytoplasm by pumps and transporters

Answer 265

iCa

Question 266

caMP, DAG, IP3, or iCa???

Generated from PIP2 and diffuses in the cytoplasm

Answer 266

IP3

Question 267

caMP, DAG, IP3, or iCa???

Activates PKA

Answer 267

cAMP

Question 268

caMP, DAG, IP3, or iCa???

Adenylyl cyclase catalyzes production

Answer 268

cAMP

Question 269

caMP, DAG, IP3, or iCa???

ATP is the precursor

Answer 269

cAMP

Question 270

Which G protein alpha subunit activates adenylyl cyclase?

Answer 270

G-alpha S activates adenylyl cyclase

Question 271

Which 2 Ca transporters are found in the plasma membrane

Answer 271

1. sodium-calcium exchanger (NCX)
2. Ca2+ ATPase (pump, PMCA)

Question 272

What enzyme family catalyzes the addition of a phosphate group to a substrate?

Answer 272

Kinases catalyze the addition of a phosphate group to their substrates

Question 273

What enzyme produces IP3 and DAG from PIP2?

Answer 273

PLC (phopholipase C)

Question 274

The 2 types of synpases in the human body are (select 2):
a. chemical
b. thermal
c. mechanical
d. electrical

Answer 274

A and D

Question 275

_____ play a crucial role in AP and other electrical behavior of membranes.

Answer 275

Ion channels

Question 276

Ion channels usually have what type of pores?

Answer 276

gated

Question 277

What helps the nervous system get the right signal to the right place in the body at the right time?

Answer 277

An intercellular junction called the synpase

Question 278

What are the two types of synapses?

Answer 278

electrical and chemical

Question 279

____ synapses are far more prevalent and diverse.

Answer 279

Chemical

Question 280

____ receptors are the key proteins of signal transduction at chemical synapses.

Answer 280

NT

Question 281

NT receptors are transmembrane proteins that are either:
1. _____
2. _____

Answer 281

1. ion channels (ionotropic receptors)
2. coupled to heterotrimeric G proteins (metabotropic receptors)

Question 282

____ synapses are polarized. What does this mean?

Answer 282

Chemical; primarily one-way communication

Question 283

What are chemical synapses comprised of?

Answer 283

A presynaptic terminal, synaptic cleft, and postsynaptic membrane

Question 284

What is the presynaptic terminal also called?

Answer 284

axon terminal, synaptic bouton, or synaptic knobs

Question 285

How wide is the synaptic cleft on chemical synapses?

Answer 285

20-40 nm wide

Question 286

Ion channels are integral membrane proteins that form ________ pores through which selected ions can pass.

Answer 286

water-filled pores

Question 287

T/F: Ion channels exhibit ion selectivity.

Answer 287

True

Question 288

What type of channels usually have gated pores?

Answer 288

Ion channels

Question 289

What are the 3 different types of gated ion channels?

Answer 289

1. voltage-gated (membrane)
2. ligand-gated (chemical)
3. Mechanically-gated (pressure/sensory receptors)

Question 290

T/F: ALL ion channels are gated.

Answer 290

False - not all ion channels are gated

Question 291

What is an example of an ion channel that is not gated?

Answer 291

“leaky” potassium channels that establish resting membrane potential

Question 292

Chemical synapses convert a ____ signal ➡ a ____ signal through the release of NT.

Answer 292

electrical; chemical

Question 293

Chemical synapses communicate messages in what direction?

Answer 293

one direction from the presynaptic membrane to the postsynaptic membrane, across the synaptic cleft

Question 294

NT act as endocrine, paracrine, or autocrine messengers?

Answer 294

paracrine and autocrine messengers

Question 295

NT act as 1st or 2nd messenger?

Answer 295

1st - they bind to receptors and generate electrical or biochemical signals in postsynaptic cells

Question 296

What type of synapses allow bi-directional flow?

Answer 296

Electrical

Question 297

At electrical synapses, cells are connected by what?

Answer 297

gap junctions

Question 298

Gap junctions consist of 2 hemichannels called _____.

Answer 298

connexions

Question 299

What allows the myocardial cells to depolarize synchronously?

Answer 299

intercalated discs in the heart that contain electrical synapses

Question 300

All ionotropic receptors have ____ subunits whose arrangement defines a central pore.

Answer 300

4-5

Question 301

When does ionotropic receptor activation cease?

Answer 301

When the NT dissociates from the receptor or when the receptor is desensitized

Question 302

Ionotropic receptors participate in fast or slow synaptic responses?

Answer 302

Fast

Question 303

What are metabotropic receptors?

Answer 303

7 transmembrane-spanning receptors coupled to heterotrimeric G proteins (GPCR)

Question 304

Metabotropic receptors participate in ____responses compared to inotropic receptors.

Answer 304

slower (seconds to minutes); compared to milliseconds or faster

Question 305

AChr, adrenergic receptors, GABAbR, opioid receptors, and 5-HT1R are all _____ receptors.

Answer 305

metabotropic

Question 306

What receptors trigger biochemical cascade?

Answer 306

Metabotropic - tip it sounds like metabolism or metabolite… it activates enzymes

Question 307

The presynaptic terminal of chemical synapses contain what 2 important organells?

Answer 307

Mitochondria
Synaptic vesicles

Question 308

What is mitochondria’s job in presynaptic terminals?

Answer 308

provides ATP, biochemical intermediates, and enzymes for the syntehsis and degradation of NT

Question 309

What is synaptic vesicles job in presynaptic terminals?

Answer 309

concentrate, store, and deliver NT at the synapse

Question 310

Membrane depolarization causes _____ channels (N-type) to open, permitting Ca2+ ions to flow into the terminal.

Answer 310

Ca2+

Question 311

Increased intracellular Ca2+ is sensed by _____ in the docking proteins complex. This triggers the fusion of vesicles with the presynaptic membrane. This process is _____.

Answer 311

synaptotagmin; exocytosis

Question 312

NT molecules bind to either ____ or _____ receptors on the post-synaptic membrane, leading to a post-synaptic event.

Answer 312

ionotropic or metabotropic

Question 313

Volatile anesthetics inhibit excitatory neurotransmission (via ___ and ____ receptors).

Answer 313

NMDA and nicotinic ACh

Question 314

Volatile anesthetics enhance inhibitor neurotransmission (via ___ and ____ receptors).

Answer 314

GABA and glycine

Question 315

What causes hyperpolarization?

Answer 315

outward current of K+,
Cl= influx,
closure of Ca2+ channels

Question 316

What causes depolarizatin?

Answer 316

net inward current of:
Na+ influx
Ca2+ influx
Reduced K+ efflux through leaky channels

Question 317

Ionotropic receptor OR metabotropic receptor???

Conformational change sets in motion a biochemical cascade

Answer 317

Metabotropic

Question 318

Ionotropic receptor OR metabotropic receptor???

Slower synaptic response

Answer 318

Metabotropic

Question 319

Ionotropic receptor OR metabotropic receptor???

Muscarinic AChR

Answer 319

Metabotropic

Question 320

Ionotropic receptor OR metabotropic receptor???

5-HT3R

Answer 320

Ionotropic

Question 321

Ionotropic receptor OR metabotropic receptor???

Conformational change gates a pore

Answer 321

Ionotropic

Question 322

Ionotropic receptor OR metabotropic receptor???

Nicotinic AChR

Answer 322

Ionotropic

Question 323

Ionotropic receptor OR metabotropic receptor???

Opioid Receptor

Answer 323

Metabotropic

Question 324

Ionotropic receptor OR metabotropic receptor???

Fast synaptic response

Answer 324

ionotropic

Question 325

List 2 gases that are unconventional NT.

Answer 325

NO
CO

Question 326

What structure connects cells at an electrical synapse?

Answer 326

Gap junctions (connexions form gap junctions)

Question 327

Which protein in the docking complex is the calcium sensor?

Answer 327

Synaptotagmin

Question 328

Name 3 signals that open pores in gated ion channels.

Answer 328

Membrane voltage (electrical), chemicals (ligands), and pressure (mechanical)

Question 329

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

DOPAMINE

Answer 329

Biogenic Amine

Question 330

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

VASOACTIVE INTESTINAL PEPTIDE (VIP)

Answer 330

Neuropeptide

Question 331

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

OPIOIDS

Answer 331

Neuropeptide

Question 332

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

NOREPINEPHRINE

Answer 332

Biogenic Amine

Question 333

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

ANANDAMIDE

Answer 333

Nonconventional

Question 334

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

GLUTAMATE

Answer 334

Amino Acid

Question 335

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

NITRIC OXIDE

Answer 335

Nonconventional

Question 336

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

GLYCINE

Answer 336

Amino Acid

Question 337

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

SUBSTANCE P

Answer 337

Neuropeptide

Question 338

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

GABA

Answer 338

Amino Acid

Question 339

Sort each NT into the correct pile: Biogenic Amine, Neuropeptide, Amino Acid, or Nonconventional

SEROTONIN

Answer 339

Biogenic Amine

Question 340

Where are nicotinic acetylcholine receptors NOT located?
a. autonomic ganglia
b. neuromuscular junction
c. chromaffin cells in the adrenal medulla
d. sinoatrial node

Answer 340

D - sinoatrial node

Question 341

What is the primary NT of peripheral EFFERENT (motor) neural pathways?

Answer 341

Acetylcholine (ACh)

Question 342

What role does Acetylcholine play in the CNS?

Answer 342

• the modulation of sleep
• wakefulness (in the RAS)
• learning
• memory

Question 343

Where does Acetylcholine synthesis occur?

Answer 343

In the presynaptic nerve terminal

Question 344

T/F: Cholinergic receptors can be ionotropic or metabotropic.

Answer 344

True

Question 345

Are nicotinic ACh receptors ionotropic or metabotropic?

Answer 345

ionotropic

Question 346

Are muscarinic ACh receptors ionotropic or metabotropic?

Answer 346

metabotropic

Question 347

Cholinergic describes neurons or synapses that use ____ as the neurotransmitter.

Answer 347

Acetylcholine

Question 348

Acetylcholine is the primary NT of peripheral efferent or afferent neural pathways?

Answer 348

EFFERENT

Question 349

List all the places ACh is a NT at:
1.
2.
3.
4.
5.

Answer 349

1. NMJ
2. Autonomic ganglia
3. Terminal synapses of parasympathetic postganglionic fibers
4. Few sympathetic postganglionic fibers (sweat glands)
5. NOn-neuronal cholinergic system (NNCS)

Question 350

T/F: Only nicotinic receptors are expressed in the central neurons, not muscarinic receptors.

Answer 350

False - both are

Question 351

What are the substrates of acetylcholine?

Answer 351

choline and acetyl-CoA

Question 352

What is the rate-limiting factor for the availability of Acetylcholine?

Answer 352

The availability of its substrates (choline and acetyl-CoA)

Question 353

How does glucose enter nerve terminals?

Answer 353

by passive transport (facilitated diffusion)

Question 354

Glycolysis converts glucose to ______.

Answer 354

pyruvate

Question 355

Where does glycolysis occur?

Answer 355

in the cytoplasm

Question 356

An acetyl group from pyruvate is added to coenzyme A to produce _____.

Answer 356

acetyl-CoA

Question 357

Choline is ______ transported into the presynaptic terminal.

Answer 357

actively

Question 358

________ is the rate-limiting step in ACh synthesis.

Answer 358

Choline transport

Question 359

What catalyzes the formation of ACh from acetyl-CoA + choline?

Answer 359

Choline acetyltransferase (ChAT)

Question 360

Where is ACh stored?

Answer 360

In synaptic vesicles until release

Question 361

How is ACh transported into vesciles?

Answer 361

By an H+-antiporter (exchanger)

Question 362

_____ triggers vesicle fusion at the active zone, and ____ is released into the synaptic cleft by exocytosis.

Answer 362

Increased intracellular Ca2+; ACh

Question 363

What hydrolyzes ACh? What is it hydorlyzed to?

Answer 363

Acetylcholinesterase (AChE); acetate + choline

Question 364

What happens to the choline that is produced durign ACh hydrolysis?

Answer 364

It re-enters the nerve terminal and is reused for ACh synthesis

Question 365

What is an antagonist of Ca2+ at the presynaptic nerve terminal?

Answer 365

Mg2+

Question 366

Why does Mg2+ cause muscle weakness or potentiate NM block?

Answer 366

It is an antagonist of Ca2+ at the presynaptic nerve terminal

Question 367

Nicotinic ACh recetpors (nAChR) are inotropic or metabotropic receptors?

Answer 367

Inotropic

Question 368

T/F: nAChRs are nonselective anion channels.

Answer 368

F - nAChRs are nonselective cation channels.

Question 369

Describe the structure of nAChRs.

Answer 369

They are pentameric complexes with 2 agonist binding sites - one at the extracellular 𝜶/ε interface of one 𝜶 subunit and the 𝜶/𝛅 interface of the other 𝜶 subunit

Question 370

What is required to initiate the conformational change that opens the nAChR channels?

Answer 370

simultaneous binding of 2 ACh molecules to the alpha subunits

Question 371

Where are NmAChRs found?

Answer 371

in skeletal muscle at the NMJ

Question 372

Where are NnAChRs found?

Answer 372

in the autonomic ganglia, on the chromaffin cells of the adrenal medulla, and in the CNS

Question 373

As their name implies, nAChR can be opened by the ____plant, _____.

Answer 373

tobacco plant, alkaloid nicotine

Question 374

Muscarinic ACh receptors (mAChR) are inotropic or metabotropic receptors?

Answer 374

Metabotropic

Question 375

Where are muscarinic AChRs found?

Answer 375

CNS, heart, smooth muscle, and glands of GI tract

Question 376

_____ mediate most action of ACh in the CNS.

Answer 376

mAChR

Question 377

Muscarinic AChRs are so named b/c they are activated by ____, a _____ found in a poisonous mushroom.

Answer 377

muscarine, a toxic alkaloid

Question 378

How many types of mAChR have been identified?

Answer 378

5

Question 379

Where are NM (nicotinic ACh) receptors found?

Answer 379

Skeletal muscle at NMJ

Question 380

What is the signal transduction of NM (nicotinic ACh) receptors?

Answer 380

Opening of nonselective cation channels –> influx of Na

Question 381

What is the response of activated NM (nicotinic ACh) receptors?

Answer 381

end-plate depolarization and skeletal muscle contraction

Question 382

Where are NN (nicotinic ACh) receptors found?

Answer 382

Autonomic ganglia, adrenal medulla, CNS

Question 383

Where are M1 (muscarinic ACh) receptors found?

Answer 383

autonomic ganglia

CNA

Question 384

Where are M2 (muscarinic ACh) receptors found?

Answer 384

Heart: nodal tissue
Heart: cardiac muscle

Question 385

Where are M3 (muscarinic ACh) receptors found?

Answer 385

Smooth muslce; GI

Question 386

Where are M4 (muscarinic ACh) receptors found?

Answer 386

CNS

Question 387

Where are M5 (muscarinic ACh) receptors found?

Answer 387

CNS

Question 388

What muscarinic receptors are found in the heart?

Answer 388

M2

Question 389

What muscarinic receptors are found in the GI tract?

Answer 389

M3

Question 390

What is the signal transduction of NN (nicotinic ACh) receptors?

Answer 390

Opening of nonselective cation channels –> influx of sodium

Question 391

What is the signal transduction of M1, M3, and M5 (muscarinic ACh) receptors?

Answer 391

Gq,11 –> PLC –> increased IP3 + increased DAG –> increased Ca2+ –> increased PKC

ALL ODD MUSCARINIC ARE COUPLED TO GQ

Question 392

What is the signal transduction of M2 and M4 (muscarinic ACh) receptors?

Answer 392

βᵞ subunit of Gi –> increased K+ channel (GIRK) opening

Gi –> inhibition of AC –> decreased cAMP

ALL EVEN MUSCARINIC ARE COUPLED TO Gi

Question 393

What is the response of activated NN (nicotinic ACh) receptors?

Answer 393

Depolarization of post-synaptic post-ganglionic neuron

Secretion of catecholamines

Arousal, attention, analgesia

Question 394

What is the response of activated M1 (muscarinic ACh) receptors?

Answer 394

Excitatory response

Arousal, attention, analgesia

Question 395

What is the response of activated M2 (muscarinic ACh) receptors?

Answer 395

Slowed spontaneous depolarization

DECREASES chronotropy, contracitlity, and domotropy

Question 396

What is the response of activated M3 (muscarinic ACh) receptors?

Answer 396

Contraction

Increased salivary secretions

Question 397

What is the response of activated M4 (muscarinic ACh) receptors?

Answer 397

Presynaptic autoreceptors –> negative feedback to supress ACh release

Question 398

What is the response of activated M5 (muscarinic ACh) receptors?

Answer 398

Promotes dopamine release, dilation of cerebral arteries

Question 399

Muscarinic AChR or Nicotinic AChR????

Binding of 2 Ach molecules for full activation

Answer 399

Nicotinic

Question 400

Muscarinic AChR or Nicotinic AChR????

Ionotropic

Answer 400

Nicotinic

Question 401

Muscarinic AChR or Nicotinic AChR????

NMJ

Answer 401

Nicotnic

Question 402

Muscarinic AChR or Nicotinic AChR????

Slowed spontaneous depolarization of SA node

Answer 402

Muscarinic

Question 403

Muscarinic AChR or Nicotinic AChR????

Coupled to heterotrimeric G protein

Answer 403

Muscarinic

Question 404

Muscarinic AChR or Nicotinic AChR????

Secretion of catecholamines from adrenal medulla

Answer 404

Nicotonic

Question 405

Muscarinic AChR or Nicotinic AChR????

Nonselective cation channel

Answer 405

Nicotinic

Question 406

Muscarinic AChR or Nicotinic AChR????

Metabotropic

Answer 406

Muscarinic

Question 407

Muscarinic AChR or Nicotinic AChR????

Presynaptic autoreceptors

Answer 407

muscarinic

Question 408

Muscarinic AChR or Nicotinic AChR????

Airway smooth muscle

Answer 408

Muscarinic

Question 409

The NMDA receptor has bindings sites for: (select 3)
a. gamma-aminobutyric acid
b. glutamate
c. propofol
d. ketamine
e. magnesium
f. calcium

Answer 409

B - glutamate
d - ketamine
e - magnesium

Question 410

The amino acid NT include ____, ____, and _____.

Answer 410

gutamate, ᵧ-aminobutyric acid (GABA), glycine

Question 411

_____ is the primary excitatory NT in the brain.

Answer 411

GLUTAMATE

Question 412

What is the main inhibitory NT in the brain?

Answer 412

GABA

Question 413

What is the primary inhibitor NT in teh spinal cord and lower brain stem?

Answer 413

GLYCINE

Question 414

____ and ____ are interconvertible through Krebs cycle (aka tricarboxylic acid cycle) intermediates.

Answer 414

Gutamate and GABA

Question 415

Are glutamate receptors inotropic or metabotropic?

Answer 415

they can be both

Question 416

What receptors are a target for ketamine?

Answer 416

NMDA

Question 417

What are the two ionotropic glutamate receptors?

Answer 417

NMDA and AMPA

Question 418

What is neuronal injury initiated by excessive glutamate receptor activity called?

Answer 418

excitotoxicity

Question 419

GABA receptors can be ionotropic and metabotropic. Which is which?

Answer 419

GABAa = ionotropic
GABAb = metabotropic

Question 420

Which receptor is a target for Benzos, propofol, etomidate, and volatiles?

Answer 420

GABAa

Question 421

Is the glycine receptor ionotropic or metabotropic?

Answer 421

ionotropic

Question 422

Is glutamate excitatory or inhibitory?

Answer 422

excitatory

Question 423

Glutamatergic synapses exist throughout the ____.

Answer 423

CNS

Question 424

What are excitatory responses to gluatmate?

Answer 424

motor neuron activation, pain pathway transmission, elevated pain sensation (hyperalgesia), memory formation, cerebral neurotoxicity

Question 425

Is GABA inhibitory or excitatory?

Answer 425

Inhibitory

Question 426

Most CNS ____ and ____ express GABA receptors; therefore, GABA receptors influence many neural circuits and functions.

Answer 426

neurons and astrocytes

Question 427

GABA neurons play a role in what?

Answer 427

arousal and attention; memory formation; anxiety; sleep; muscle tone

Question 428

Is glycine inhibitory or excitatory?

Answer 428

inhibitor

Question 429

What type of cells form inhibitory glycinergic synapses upon alpha motor neurons?

Answer 429

Renshaw

Question 430

Why myst glutamate be synthesized in the brain?

Answer 430

B/c it canNOT cross the BBB

Question 431

How is glutamate converted to GABA?

Answer 431

By glutamic acid decarboxylase

Question 432

IN one path for glutamate synthesis, _____ produced by the Krebs cycle serves as the substrate for GABA transaminase. What is the the product of transamination?

Answer 432

𝜶-ketoglutarate; glutamate

Question 433

How is glutamine converted into glutamate?

Answer 433

By glutaminase on the mitochondiral membrane

Question 434

What is the rate-limiting step in glutamate synthesis?

Answer 434

Glutaminase activity

Question 435

Where is glutamate stored until release?

Answer 435

synpatic vesicles

Question 436

______ reuptake glutamate from the synaptic cleft via glutamate transporters.

Answer 436

Glial cells (glutamate is converted into glutamine by the enzyme glutamine synthetase)

Question 437

What are teh 3 types of ionotropic glutamate receptors?

Answer 437

1. N-methyl-D-aspartate (NMDA)
2. 𝜶-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)
3. Kainate

Question 438

Where are NMDA and AMPAs both prevalently located?

Answer 438

hippocampus and cerebral cortex

Question 439

Full activation of AMPA receptors requires waht?

Answer 439

binding of 2 glutamate molecules

Question 440

AMPA receptors are non-selective cation channels that are highly permeable to ___ and poorly permeable to ___.

Answer 440

Na; Ca

Question 441

AMPA are responsible for early post-synpatic membrane depolarization in response to _____ release.

Answer 441

glutamate

Question 442

What plays a key role in AMPA desnsitization?

Answer 442

Phosphorylation

Question 443

Full activation of NMDA receptors requires the binding of 2 ____, 2 _____ and a ______.

Answer 443

glutamates; glycine; depolarizing voltage change

These are safety locks on the NMDA receptor - each must be met for full activation

Question 444

NMDA receptors are non-selective cation channels that are highly permeable to ___ but permeable to ___.

Answer 444

Ca; Na

(opposite of AMPA)

Question 445

NMDAs are slower or faster gated than AMPA?

Answer 445

slower

NMDAs are slower-gating (Delayed) excitatory synaptic transmission.

Question 446

NMDA: a _____ binding site is located within the channel, this is also the binding site for ketamine.

Answer 446

phencyclidine (phenylcyclohexyl piperidine, PCP; “angel dust”)

Question 447

What are the 3 groups of metabotropic glutamate receptors?

Answer 447

1. 1 coupled to Gq and activate phospholipase C
   2 & 3. coupled to Gi and prevent the formation of cAMP

Question 448

Metabotropic glutamate receptors are widely distributed where?

Answer 448

in the brain at post and pre synaptic locations and on glial cells

Question 449

What is long-term potentiation?

Answer 449

Ca+ influx through NMDA receptors plays a key role in many Ca- dependent processes, including the consolidation of short-term memories –> long term memories

Question 450

What is apoptosis?

Answer 450

programmed cell death

Question 451

What diseases is excitotoxicity implicated as a pathologic mechanism?

Answer 451

Huntington’s, Alzheimer’s, ALS, stroke and trauma, hyperalgesia, epilepsy

Question 452

What are the three safety locks of NMDA receptors?

Answer 452

voltage-dependence
2 glutamate bindings
2 glycine bindings

Question 453

Why do safety locks for NMDA receptors exist?

Answer 453

Hyperactivation would result in flooding of neurons by Ca2+ causing cell death

Question 454

What catalyzes the decarboxylation of glutamate to GABA?

Answer 454

Glutamic acid decarboxylase

Question 455

The amount of GABA in the CNS correlates to the amount of functional ____.

Answer 455

Glutamic acid decarboxylase (GAD)

Question 456

Where does conversion of glutamine to glutamate occur?

Answer 456

mitochondria

Question 457

What converts glutamine to glutamate?

Answer 457

glutaminase

Question 458

How is GABA formed and where?

Answer 458

By the decarboxylation of glutamate; in the cytoplasm

Question 459

T/F: GAD is not present in neurons using glutamate as a NT.

Answer 459

True

Question 460

Is GABA recylced?

Answer 460

Yes

Question 461

How are GABAa receptors activated?

Answer 461

the binding of 2 GABA molecules

Question 462

GABA_ receptors are pentameric ligand-gated Cl- channels.

Answer 462

A

Question 463

GABA _ receptors are 7-transmembrane G protein-coupled receptors.

Answer 463

B

Question 464

Activation of GABAb generates inhibitory effects in post-synaptic neurons via second messenger systes involving:
____
____
____
____

Answer 464

PLC
adenylyl cyclase
βᵞ unit opening of K+ channels
βᵞ closing of Ca2+ channels

Question 465

How is glycine formed?

Answer 465

From serine (an amino acid) in an enzyme-catalyzed reaction

Question 466

______ is a co-activator of the NMDA receptor.

Answer 466

Glycine

Question 467

Mutations of the glycine receptors are involved in rare neuro dx such as ____ or ____

Answer 467

human startle dx or hyperekplexia

Question 468

GABAa OR NMDA??????

Excitatory responses

Answer 468

NMDA

Question 469

GABAa OR NMDA??????

Flumazenil is antagonist

Answer 469

GABA

Question 470

GABAa OR NMDA??????

Propofol binding site

Answer 470

GABA

Question 471

GABAa OR NMDA??????

Benzo binding site

Answer 471

GABA

Question 472

GABAa OR NMDA??????

Inhibitory response

Answer 472

GABA

Question 473

GABAa OR NMDA??????

Mg ions block channel at resting membrane potential

Answer 473

NMDA

Question 474

GABAa OR NMDA??????

KEtamine binding site

Answer 474

NMDA

Question 475

GABAa OR NMDA??????

Glycine is a co-transmitter

Answer 475

NMDA

Question 476

What is the primary inhibitory NT in the spinal cord?

Answer 476

Glycine

Question 477

Which NT is associated w/ excitotoxicity?

Answer 477

Glutamate

Question 478

WHich GABA receptor is metabotropic?

Answer 478

b

Question 479

What 2 binding sites are located in the NMDA receptor channel (pore)?

Answer 479

Mg2+ and Ketamine/PCP

Question 480

Glutamate is converted to GABA by what type of enzymatic reaction?

Answer 480

Decarboxylation

Question 481

Which enzymes are required to degrade epinephrine to vanillylmandelic acid? (select 2)
a. catechol-O-methyltransferase
b. L-amino acid decarboxylase
c. monomaine oxidase
d. tyrosine hydroxylase

Answer 481

A and C

Question 482

What are the 5 biogenic amine NT?

Answer 482

1. dopamine
2. norephinephrine
3. ephinephrine
4. serotonin
5. histamine

Question 483

What are all teh biogenic amine NT derived from?

Answer 483

amino acids by enzymatic hydroxylation and decarboxylation

Question 484

What 3 things are known as catecholamines?

Answer 484

dopamine, norepinephrine, epinephrine

Question 485

______ is the rate limiting step in catecholamine biosynthesis.

Answer 485

Tyrosine hydroxylase

Question 486

What 2 enzymes degrade NE and Epi?

Answer 486

1. monoamine oxidase (MAO)
2. catechol-O-methyltransferase (COMT)

Question 487

What is the end-product of catecholamine metabolism?

Answer 487

Vanillylmandelic acid (VMA)

Question 488

How is VMA eliminated?

Answer 488

urine

Question 489

serotonin is synthesized from ____

Answer 489

tryptophan

Question 490

What is the end product of serotonin metabolism?

Answer 490

5-hydroxyindoleacetic acid (5-HIAA)

Question 491

How is 5-HIAA eliminated?

Answer 491

urine

Question 492

Histamine is synthesized from _____

Answer 492

histidine

Question 493

What physiologic responses do biogenic animes cause?

Answer 493

central control of cardiac function, BP, and metabolism; coordination of movement; cognitive function; regulation of appetite and feeding; sleep; behavior

Question 494

Most biogenic amine NT receptors are _______ receptors. What is the exception?

Answer 494

metabotropic; ionotropic 5-HT3 serotonin receptor

Question 495

All catecholamines are synthesized from ______.

Answer 495

tyrosine

Question 496

Serotonin is synthesized from _______.

Answer 496

tryptophan

Question 497

Histamine is synthesized from _______.

Answer 497

histidine

Question 498

All biogenic amine NT are synthesized rom _______

Answer 498

amino acids

Question 499

What 2 enzymatic reactions are common in the biosynthesis of biogenic amine NT?

Answer 499

Hydroxylation and decarboxylation

Question 500

What occurs during hydroxylation?

Answer 500

An -OH group is added

Question 501

What occurs during decarboxylation?

Answer 501

A -CO2 group is removed

Question 502

If tyrosine supply is low, how can cells generate tyrosine?

Answer 502

From phenylalanine by hydroxylation

(tip: [maybe??? lol] the alternate name for tyrosine is hydroxyphenylalanine)

Question 503

Tyrosine is hydroxylated or decarboxylated by the enzyme tyrosine hydroxylase? What is formed?

Answer 503

HYDROXYLATED; L-DOPA

Question 504

What is the rate-limiting step in catecholamine synthesis?

Answer 504

Tyrosine hydroxylation to L-DOPA

Question 505

During catecholamine synthesis, tyrosine hydoxylase is subject to feedback inhibition by what?

Answer 505

Dopamine and NE

Question 506

During catecholamine synthesis, is L-DOPA hydroxylated or decarboxylated by aromatic L-amino acid decarboxylase? What is the result?

Answer 506

Decarboxylated; dopamine

Question 507

After Dopamine is formed from L-DOPA where does it go?

Answer 507

It is transported into vesicles by an H+-antiporter. If the neuron is dopaminergic, the path stops here.

Question 508

In nonadrenergic and adrenergic neurons or chromaffin cells, the path of catecholamine synthesis continues after Dopamine formation. In the storage vesicles, does hydroxylation or decarboxylation of the dopamine occur? What results?

Answer 508

Hydroxylation (by dopamine-β-hydroxylase); Norepinephrine

Question 509

During catecholamine synthesis, in adrenergic cells and neurons, norepinephrine moves out of the vesicles to where? What does it encounter?

Answer 509

cytoplasm; phenylethanolamine-N-methyltransferase (PNMT)

Question 510

PNMT catalyzes the ______ of NE to form ______.

Answer 510

methylation (CH3); epinephrine

Question 511

Put these in order for which they are created: Norepinephrine, Dopamine, and Epinehprine

Answer 511

Dopamine –> Norepinephrine –> Epinephrine

Question 512

What 2 enzymes metabolize catecholamines?

Answer 512

Monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT)

Question 513

____ is a mitochondrial outer-membrane enzyme found in most neurons and other tissues.

Answer 513

MAO

Question 514

What two isoforms does MAO exist in?

Answer 514

MAO-A and MAO-B

Question 515

What does MAO-A preferentially degrade?

Answer 515

Dopamine, Epi, serotonin

Question 516

what does MAO-B degrade?

Answer 516

Dopamine more rapidly than serotonin or NE

Question 517

_____ is a relatively nonspecific cytosolic enzyme found in endothelial cells, the heart, kidneys, liver, smooth muscle, and glial cells.

Answer 517

COMT

Question 518

What is the end-product of catecholamien metabolism?

Answer 518

Vanillymandelic acid

Question 519

How is pheochromocytoma diagnosis made?

Answer 519

biochemical determination of free catecholamine concentration and catecholamine metabolites (VMA) in urine

Question 520

What is the major metabolite of dopamine? How is Dopamine metabolized?

Answer 520

Homovanillic acid (HVA); MAO and COMT

Question 521

Does serotonin cross the BBB?

Answer 521

No (brain must synthesize its own)

Question 522

What is the substrate for serotonin synthesis?

Answer 522

Dietary L-tryptophan

Question 523

What is serotonin metabolized to?

Answer 523

5-hydroxyindoleacetic acid (5-HIAA)

Question 524

How is 5-HIAA excreted? What do high levels in the urine show?

Answer 524

urine; consistent w/ carcinoid tumors

Question 525

______ is an imidazole amine consisting of an imidazole ring and an amino group connected by 2 methylene groups.

Answer 525

Histamine

Question 526

How is histamine synthesized in the periphery?

Answer 526

By mast cells and basophils

Question 527

Does histamine cross the BBB?

Answer 527

No

Question 528

The brain synthesizes its own histamine from _______.

Answer 528

L-histidine (an amino acid)

Question 529

Histidine is _______ to form histamine

Answer 529

decarboxylated

Question 530

What metabolizes histamine?

Answer 530

oxidative paths in liver

Question 531

What is one major metabolite of histamine that can be measured in the urine to determine the amount of histamien that has been released systemically?

Answer 531

imidazole acetic acid

Question 532

All catecholamine NT are derived from which amino acid?

Answer 532

L-tyrosine

Question 533

What enxymatic reaction is present in ALL biogenic amine NT biosynthesis?

Answer 533

Decarboxylation

Question 534

Match each adrenergic receptor with the G protein alpha subunit coupled to the receptor: alpha 2; alpha 1; beta
& Gq, Gi, Gs

Answer 534

Alpha-2 Receptor - Gi
Alpha-1 Receptor - Gq
Beta Receptor - Gs

Question 535

How are biogenic amine NT removed from the synaptic cleft?

Answer 535

By reuptake into the presynaptic terminal or uptake into non-neuronal cells and organs

Question 536

What are the 3 main classes adrenergic receptors can be divided into?

Answer 536

Alpha-1
Alpha-2
Beta

Question 537

Derangements of serotonergic paths contribute to what?

Answer 537

Anxiety, depression, mania, schizophrenia

Question 538

What serotonin receptor is the target of antagonists for PONV and Chemo-induced N/V?

Answer 538

5-HT3

Question 539

What role do serotonergic neurons play?

Answer 539

sleep and wakefulness, emotions, cognition, and CV, respiratory, and intestional activitives

Question 540

What role do histaminergic neurons play?

Answer 540

arousal and attention, memory, learning, mood

Question 541

About ___% of the dopamine entering the terminal is recycled into vesicles by the H+-antiporter. The remaining ___% is destroyed by the mitochondrial enzyme MAO.

Answer 541

50%; 50%

Question 542

Where is the largest concentration of dopaminergic neurons in the brain?

Answer 542

the substantia nigra

Question 543

The dopaminergic neurons in the substantia nigra are crucial for what?

Answer 543

coordinating movements

Question 544

Degeneration of Dopaminergic neurons in the substantia nigra causes _______.

Answer 544

Parkinson’s disease

Question 545

Besides the substantia nigra, other dopaminergic neurons in the CNS are involved with ______ and ______.

Answer 545

motivation and reward (limbic system) and cognitive functions such as spatial learning and memory (prefrontal cortext)

Question 546

How many types of dopamine receptors are there?

Answer 546

5

Question 547

The D1-like dopamine receptors are ___ and ____. They activate what?

Answer 547

D1 and D5; PKA through adenylyl cyclase and cAMP, and PKC through PLC

Question 548

The D2-like dopamine receptors are ___, _____, and ____. They inhibit what?

Answer 548

D2, D3, and D4; inhibit adenylyl cyclase and thus reduce PKA activity which ultimately leads to decreased neuronal excitability

Question 549

What is implicated in the pathogensis of schizophrenia?

Answer 549

Overactive D2-like receptors

Question 550

Where is the major concentration of noradrenergic neurons in the CNS?

Answer 550

Locus coeruleus in the pons

Question 551

Noradrenergic neurons from the locus coeruleus reach the ___, ____, ____ and ____.

Answer 551

thalamus, hypothalamus, limbic system, and cerebral cortex

Question 552

What the noradrenergic projections important in?

Answer 552

arousal, attention (Vigilance ), and feeding behaviors

Question 553

2 major groups of adrenergic (epi) neurons have been identified in the CNS:
1. _________________
2. _________________

Answer 553

1. Rostral ventrolateral medulla
2. Nucleus tractus solitarius

Question 554

In the peripheral nervous system, NE is released from where?

Answer 554

from most post-ganglionic symapthetic neurons onto the target tissues

Question 555

In the peripheral nervous system, Epi is released from where?

Answer 555

chromaffin cells of the adrenal medulla into the circulation in response to stress

Question 556

All adrenergic receptors are metabotropic or ionotropic?

Answer 556

Metabotropic

Question 557

Adrenergic receptor classes are distinguished by their relative sensitivity to _____.

Answer 557

Isoproterenol (N-isopropyl-noradrenaline)

Question 558

Isoproterenol activates ____ receptors, whereas ____ receptors are poorly activated by isoproterenol.

Answer 558

Beta; alpha

Question 559

NE preferentially binds to what receptors?

Answer 559

A1, A2, and B1

Question 560

Activation of ______ results in inhibition of NE release

Answer 560

presynaptic alpha-2

Question 561

Epi is an agonist of what receptors?

Answer 561

alpha and beta

Question 562

At low concentrations Epi has predominately ____ effects, while at higher concentrations, its ___ effects become more pronounced.

Answer 562

Beta; A1

Question 563

Serotonergic neurons are clustered in several ______.

Answer 563

midline raphe nuclei

Question 564

Rostral raphe nuclei project to the ___, ___, and ____.

Answer 564

thalamus, limbic system, and cortex

Question 565

Caudal raphe nuclei project to the _______ and _____

Answer 565

spinal cord; within the brain stem

Question 566

How many of the 4 main classes of serotonin receptors are metabotropic?

Answer 566

3

Question 567

5-HT1 receptors inhibit

Answer 567

adneylyl cyclase

Question 568

5-HT2 receptors usually stimulate ___ and _____

Answer 568

stimulate PLC and mobilization of Ca2+

Question 569

5-HT4 receptors stimulate ______

Answer 569

adenylyl cylcase and pKA activation

Question 570

Activation of 5-HT3 receptors leads to rapid _____

Answer 570

membrane depolarization

Question 571

How do 5-HT3 antagonits exert their effect?

Answer 571

they block receptors in the area postrema as well as in the vagus nerve, which normally activates the vomiting center

Question 572

Where is the highest density of histamine-containing neurons found?

Answer 572

in the tuberomammillary region of the hypothalamus

Question 573

Gs, Gi, or Gq???????

5-HT4

Answer 573

Gs

Question 574

Gs, Gi, or Gq???????

Alpha-2

Answer 574

Gi

Question 575

Gs, Gi, or Gq???????

Alpha-1

Answer 575

Gq

Question 576

Gs, Gi, or Gq???????

D1

Answer 576

Gs

Question 577

Gs, Gi, or Gq???????

5-HT1

Answer 577

Gi

Question 578

Gs, Gi, or Gq???????

Beta

Answer 578

Gs

Question 579

Gs, Gi, or Gq???????

5-HT2

Answer 579

Gq

Question 580

Gs, Gi, or Gq???????

D2

Answer 580

Gi

Question 581

The largest concentration of dopaminergic neurons is in the brain is in what strucutre?

Answer 581

Substantia nigra

Question 582

What cells in the adrenal medulla release Epi into the circulation?

Answer 582

chromaffin

Question 583

Zofran targets which specific serotonin receptor?

Answer 583

5-HT3

Question 584

What is the substrate for nitric oxide synthase?
a. L-citrulline
b. Nitric oxide
c. L-arginine
d. Guanosine triphosphate

Answer 584

C

Question 585

What are the purinergic NT?

Answer 585

ATP, ADP, and adenosine

Question 586

T/F: Purinergic receptors are ionotropic.

Answer 586

False - purinergic receptors are both ionotropic and metabotropic

Question 587

ALl neuropeptides act on what receptors? and what happens?

Answer 587

metabotropic; they induce alterations in teh excitability of post-synaptic cells

Question 588

____ is a universal intercellular messenger, acting as both an autocrine and paracrine signaling molecule.

Answer 588

NO

Question 589

At body temp, NO is a small, ______ that easily permeates lipid membranes, “soaking” the surrounding tissue cell.

Answer 589

lipid-soluble gas

Question 590

What does nitric oxide synthase do?

Answer 590

converts L-arginine to L-citrulline and NO

Question 591

Many effects of NO are mediated locally by soluble guanylyl cyclase which produces ____ from GTP.

Answer 591

cGMP

Question 592

NO plays a role in central sensitization to _____

Answer 592

pain

Question 593

What roles do purine and pyrimidine nucleotides do?

Answer 593

• precursors of DNA and RNA
• components of enzymes
• energy currency
• allosteric modulators of enzymes
• second messengers
• auto-and paracrine first messengers

Question 594

Purine bases are _____ and ______

Answer 594

adenine (A) and guanosine (G)

Question 595

What are two examples of purines?

Answer 595

theophylline and caffeine

Question 596

Pyrimidine bases are ___, ____ and ____

Answer 596

cytosine (C), thymidine (T), and uracil (U)

Question 597

______ acid is a pyrimidine.

Answer 597

Barbituric

Question 598

What is a nucleotide composed of?

Answer 598

A 5-carbon sugar(pentose), nitrogenous base, and at least 1 phosphate group

Question 599

ATP, ADP and AMP and GTP, GDP, and GMP are pyrimidine or purine nucleotides?

Answer 599

Purine

Question 600

UTP, UDP, and UMP and CTP, CDP, CMP are pyrimidine or purine nucleotides?

Answer 600

Pyrimidine

Question 601

What is a nucleoside composed of?

Answer 601

A pentose and a nitrogenous base, with NO phosphate groups

(the phosphate groups differentiate a nucleoside and nucleotide)

Question 602

What are the main purinergic transmitters?

Answer 602

ATP, ADP, and adenosine

Question 603

What purinergic transmitter is frequently coreleased with other transmitters?

Answer 603

ATP

Question 604

Adenosine is generated from ___ in the extracellular space (ex: synaptic cleft) by an enzyme, _____.

Answer 604

ATP; ectonucleotidase

Question 605

Adenosine plays a role in the _____ state.

Answer 605

sleep/wake

Question 606

Increased or decreased adenosine levels promote sleep?

Answer 606

Increased

Question 607

Increased or decreased adenosine promotes wakefulness?

Answer 607

Decreased

Question 608

Adenosine plays a crucial role in protecting tissues from damage. A strong ___ in adenosine levels. in the ECF is an emergency signal indicating an acute oxygen deficiency (CVA, angina, MI)

Answer 608

INCREASE

Question 609

What dysrhythmia is adenosine indicated for? What does it do?

Answer 609

SVT; it stops the heart briefly to allow the SA node to assume the role of the dominant pacemaker

Question 610

What are purinergic NT metabolized to?

Answer 610

5’-AMP

Question 611

What are the two families of purinergic receptors?

Answer 611

P1 and P2

Question 612

Are P1 and P2Y receptors metabotropic or ionotropic?

Answer 612

Metabotropic

Question 613

Is P2X metabotropic or ionotropic?

Answer 613

Ionotropic

Question 614

What role do P2X receptors play on sensory nerves?

Answer 614

Detect and signal tissue damage and inflammation

Question 615

Some ____ receptors are found on the presynaptic membrane and serve to suppress ATP release by negative feedback through Gi paths.

Answer 615

P2Y

Question 616

PLT aggregation is induced by ADP binding to _____ receptors.

Answer 616

P2Y

Question 617

How does NO arise?

Answer 617

From the oxidation. of the guanidino group of L-arginine

Question 618

What does generation of NO require?

Answer 618

NADPH, molecular oxygen, and is catalyzed by a family of oxygenases known as NO synthases

Question 619

How many families of nitric oxide synthase are there?

Answer 619

3

Question 620

What families of nitric oxide synthase are calcium-dependent enzymes?

Answer 620

NOS1 and NOS3

Question 621

NO is both an ____ messenger and a ____ gas.

Answer 621

endogenous; cytotoxic

Question 622

NO effects depend on what?

Answer 622

Its tissue concentration

Question 623

At low concentrations, what does NO function as?

Answer 623

A signaling molecule and interacts w/ a cytoplasmic receptor, soluble guanylyl cyclase (sGC)

Question 624

At high concentrations, NO exhibits what effects?

Answer 624

Signaling effects by modifying proteins by nonenzymatic S-ntirosylation

Question 625

At extremely high concentrations of NO, what dominates?

Answer 625

the cytotoxic effects … overstimulation of NO formation plays a role in life-threatening evens such as CVA and endotoxin shock

Question 626

The _____ complex activates NOS.

Answer 626

Ca2+-calmodulin

Question 627

Activation of NOS results in the formation of ___ and ___ from L-arginine.

Answer 627

NO and citrulline

Question 628

NO interacts with the heme moiety of ______ (sGC).

Answer 628

soluble guanylate cyclase

Question 629

sGC activated by NO catalyzes the conversion of ___ to ____ in teh post-synaptic neuron.

Answer 629

GTP –> cGMP

Question 630

Retrograde diffusion of NO into the pre-synatpic terminal has a ____ feedback effect.

Answer 630

positive

Question 631

NO is a highly reactive free radical wiht a half-life of how long?

Answer 631

a few seconds

Question 632

When are functions of NO terminated?

Answer 632

When NO is converted to nitrities and nitrates by oxygen and water

Question 633

What roles do NO play?

Answer 633

sleep, controls normal feeding behavior, role in GI function

Question 634

What is long-term potentiation?

Answer 634

An activity-dependent increase in synaptic efficacy

Question 635

What is long-term depression?

Answer 635

A decrease in synpatic efficacy due to prolonged “weak” stimulation of a synapse

Question 636

NO is synthesized and released by endothelial cells and thus has an important role in the control of ______.

Answer 636

vascular tone

Question 637

Are GTP and ATP classified as purines or pyrimidines?

Answer 637

Purines

Question 638

What enzyme converts ATP to adenosine in the synaptic cleft?

Answer 638

Ectonucleotidase

Question 639

Are all neuropeptide receptors ionotropic or metabotropic?

Answer 639

Metabotropic

Question 640

What signaling complex activates nNOS?

Answer 640

Ca2+/CaM (calmodulin)

Question 641

An activity-dependent increase. in synaptic efficacy is called:

Answer 641

Long-term potentiation (LTP)

Question 642

What cytosolic heme- containing enzyme is activated by NO?

Answer 642

Soluble guanylyl cyclase (sCG)

Question 643

The receptor for insulin is a:
a. receptor guanylylcyclase
b. receptor tyrosine kinase
c. tyrosine kinase-associated receptor
d. receptor serine/threonine kinase

Answer 643

B

Question 644

What are the 5 major categories of enzyme-linked receptors?

Answer 644

1. receptor guanylylcyclase
2. receptor tyrosine kinases
3. tyrosine kinase-associted receptors
4. receptor serine/threonine kinases
5. receptor tyrosine phosphates

Question 645

Receptor _____ convert GTP to cGMP.

Answer 645

guanylyl cyclases

Question 646

What is the largest family of enzyme-linked receptors?

Answer 646

Receptor tyrosine kinases

Question 647

____ and ____ are ligands to RTKs.

Answer 647

Insulin and growth factors

Question 648

Mutations. in________ are associated with. a wide variety of cancers.

Answer 648

receptor tyrosine kinases (RTK)

Question 649

T/F: Tyrosine kinase associated receptors do not have intrinsic enzyme activity.

Answer 649

True

Question 650

Receptor _____ are important mediators of cell growth and differentiation.

Answer 650

serine-threonine kinase

Question 651

Transmembrane catalytic receptors are also known as ______ receptors

Answer 651

enzyme-linked

Question 652

What do transmembrane catalytic receptors do?

Answer 652

transduce an extracellular ligand-binding interaction into an intracellular effect by activating a “linked” enzymatic domain

Question 653

Enzyme-Linked Receptors:
________ contain a cytosolic domain that catalyzes the formation of cGMP from GTP.

Answer 653

Receptor Guanylyl Cyclases

Question 654

Enzyme-Linked Receptors:
______ are the largest group to transmembrane catalytic receptors.

Answer 654

Receptor Tyrosine Kinases

Question 655

Enzyme-Linked Receptors:
________ lack inherent catalytic activity. These receptors recruit active cytosolic signaling proteins in a ligand-dependent manner.

Answer 655

Tyrosine Kinase Associated receptors

Question 656

Enzyme-Linked Receptors:
______ have intrinisic catalytic activity and phosphorylate serine and threonine residues on target cytosolic proteins.

Answer 656

Receptor serin/threonine kinases

Question 657

Enzyme-Linked Receptors:
_______ dephosphorylate tyrosine residues on other transmembrane receptors or on cytosolic proteins. They play important roles in cells of the immune system.

Answer 657

Receptor Tyrosine Pohsphates

Question 658

Transmembrane catalytic receptors are ____ membrane-spanning proteins.

Answer 658

single

Question 659

What are. theligands for enzyme-linked receptors?

Answer 659

Polypeptides and larger proteins

Question 660

____ catalyzes teh metabolism of cGMP to 5’-GMP, terminating the actino. ofcGMP.

Answer 660

PDE5

Question 661

____, ____, and ____ are ligands for receptor guanylyl cyclases.

Answer 661

ANP, BNP, and CNP

Question 662

_______, a recombinant version of native natriuretic peptides, is used in the treatment of decompnesated HF.

Answer 662

Nesiritide

Question 663

T/F: RTKs always work in pairs.

Answer 663

True

Question 664

What tissues express higher levels of the insuline receptor?

Answer 664

energy-storing tissues of liver, muscle, and adipocytes

Question 665

Obese people have varying degrees of _____ resistance.

Answer 665

leptin

Question 666

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

Tyrosine kinase activity is built-in to the receptor

Answer 666

Receptor tyrosine kinases

Question 667

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

Insulin receptor

Answer 667

Receptor tyrosine kinases

Question 668

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

ANP is a ligand

Answer 668

Receptor guanylyl cyclases

Question 669

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

Cell differntiation

Answer 669

serine-threonin kinase receptors

Question 670

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

TGF-β is a ligand

Answer 670

Serine-threonin kinase receptors

Question 671

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

JAK-STAT system is downstream target

Answer 671

Tyrosine kinase-associated receptors

Question 672

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

Lepitn receptor

Answer 672

Tyrosine kinase-associated receptors

Question 673

Receptor Guanylyl Cyclases, receptor tyrosine kinases, tyrosine kinase-associated receptors, or serine-threonine kinase receptors????

GTP to cGMP

Answer 673

Receptor guanylyl cyclases

Question 674

Which signaling molecules bind to nuclear receptors (Select 3)?
a. Ach
b. Testosterone
c. Vit D
d. Erythropoietin
e. Triiodothyronine
f. Gamma-aminobutyric acid

Answer 674

B, C, E

Question 675

Most chemical signals bind. to receptors where?

Answer 675

transmembrane

Question 676

________ complexes are activated transcription factors that regulate the expression of target genes in the DNA.

Answer 676

Ligated (ligand-bound) nuclear receptor complexes

Question 677

The intracellular receptor family includes receptors for ____,____,___,___, and ____.

Answer 677

steroid hormones
prostaglandins
Vit d
thyroid hormones
retinoic acid

Question 678

_______ are activated transcription factors that bind. in a highly specific manner. to short DNA sequences called hormone response elements.

Answer 678

Ligand-bound nuclear receptors

Question 679

_______ increase basal metabolic rate by stimulating futile cycles of catabolism and anabolism.

Answer 679

Thyroid hormones

Question 680

What are. the2 subfamilies of nuclear receptors?

Answer 680

1. receptors for steroid hormones
2. receptors for retinoic acid, thyroid hormone, and Vit D

Question 681

Steroid hormone receptors are ______

Answer 681

homodimers (e.g., PR-PR for progesterone)

Question 682

Receptors for retinoic acid, thyroid hormones, and Vit D form heterodimers with the _______ receptor (RXR).

Answer 682

retinoic acid receptor

Question 683

Preferred Ligand: 17β-estradiol

Receptor/Transcription Factor: _______

Answer 683

Estrogen Receptor

Question 684

Preferred Ligand: Progesterone

Receptor/Transcription Factor: _______

Answer 684

Progesterone Receptor

Question 685

Preferred Ligand: Testosterone

Receptor/Transcription Factor: _______

Answer 685

Androgen Receptor

Question 686

Preferred Ligand: Cortisol

Receptor/Transcription Factor: _______

Answer 686

Glucocorticoid Receptor

Question 687

Preferred Ligand: Aldosterone

Receptor/Transcription Factor: _______

Answer 687

Mineralocorticoid receptor

Question 688

Preferred Ligand: All-trans-retinoic acid

Receptor/Transcription Factor: _______

Answer 688

Retionic acid receptor

Question 689

Preferred Ligand: 9-cis-retinoic acid

Receptor/Transcription Factor: _______

Answer 689

Retinoid X Receptor

Question 690

Preferred Ligand: Triiodothyroinine (T3)

Receptor/Transcription Factor: _______

Answer 690

Thyroid hormone receptor

Question 691

Preferred Ligand: 1,25-dihydroxycholecalciferol (D3)

Receptor/Transcription Factor: _______

Answer 691

Vitamin D Receptor

Question 692

____, ____, and _____ receptors are mainly solbule cytoplasmic receptors.

Answer 692

Glycocorticoid, mineralocorticoid, and androgen

Question 693

_____ and ____ are primarily soluble nuclear receptors.

Answer 693

Estrogen and progesterone

Question 694

INtracellular receptors are also called ____ receptors

Answer 694

Nuclear

Question 695

What nuclear receptors are bound. to DNA in the nucleus?

Answer 695

Retinoic acid, thyroid, and Vit D

Question 696

_____ nuclear receptors are frequently complexed to chaperone (“heat shock”) proteins.

Answer 696

Cytoplasmic

Question 697

T/F: Thyroid hormones have effects. onvirtually every cell in the body.

Answer 697

True

Question 698

Free thyroid hormone, T3 and T4, enters the cell how?

Answer 698

Through passive diffusion and active transport

Question 699

In the cell, T4 is usually converted to ____ by a ____.

Answer 699

T3; deiodinase

Question 700

Does the thyroid receptor in the nucleus have a greater affinity for T3 or T4?

Answer 700

T3 (10x greater affinity)

Question 701

T3 is responsible for ___% of the occupancy. of thyroid receptors in the euthyroid state.

Answer 701

90

Question 702

Ligand-bound ____ complexes bind to thyroid response elements on DNA and act as transcription activators or repressors in a tissue-specific fashion.

Answer 702

TR-RXR

Question 703

How do thyroid hormones increase basal metabolic rate?

Answer 703

By stimulating futile cycles of both catbolism and anabolism

Question 704

What stage of life are thyroid hormones essential for normal human development?

Answer 704

Infancy

Question 705

What causes congenital hypothyroidism?

Answer 705

Congenital deficiency of iodine and thus thyroid hormone during infancy

Question 706

If hypothyroidism is recognized and corrected within _____ after birth, then development - including mental development. -can proceed almost normally.

Answer 706

7 -14 days

Question 707

THe DNA-binding site for ligand-bound nuclear receptors. iscalled an:

Answer 707

Hormone response element

Question 708

An unoccupied cytoplasmic intracellular receptor is frequently complexed to a/n:

Answer 708

Chaperone protein (heat shock protein)

Question 709

An unoccupied cytoplasmic intracellular receptor is frequently complexed to a/n:

Answer 709

Chaperone protein (heat shock protein)

Question 710

WHat syndrome is associated with congenital hypothyroidism?

Answer 710

Cretinism

Question 711

Which statement is NOT a feature of cell death by apoptosis?
a. apoptosis is genetically programmed
b. cells shrink during apoptosis
c. plasma membranes are intact during apoptosis
d. inflammation in surrounding tissues is common during apoptosis

Answer 711

D

Question 712

What happens during necrosis of the cell:
Cells swell or shrinks??
What happens to DNA?
What happens to plasma membranes?
What happens to cell contents?
What happens to adjacent tissues?

Answer 712

Cell swells
DNA condenses and dissolves
Membranes are disrupted
Contents dissolve and leak out
Adjacent tissues undergo inflammatory process

Question 713

What is necrosis of the cell?

Answer 713

Cell death. by uncontrolled chaotic cellular events in response to cell injury

Question 714

What. is apoptosis of the celll?

Answer 714

Genetically controlled and programmed cell death pathways

Question 715

What happens during apoptosis of the cell:
Cells swell or shrinks??
What happens to DNA?
What happens to plasma membranes?
What happens to cell contents?
What happens to adjacent tissues?

Answer 715

-Cells shrink
-Nucleus is fragmented
-Membranes are intact
-Contents are usually intact & components are packaged into”bite-sized” apoptosomes and digested by phagocytosis
-No inflammation occurs in surrounding tissues

Question 716

T/F: Apoptosis death is normal.

Answer 716

True

Question 717

What 2 paths initiate apoptosis?

Answer 717

1. intrinsic - mitochondrial path
2. extrinsic - death receptor-initiated path

Question 718

During apoptosis, the intrinsic and extrinsic paths converge on. the____ pathway.

Answer 718

Effector (executioner)

Question 719

What drugs cause apoptosis?

Answer 719

Almost all chemo drugs cause apoptosis of cancer cells

Question 720

Excessive levels of ____ lead to neuronal injury or neuronal death by apoptosis.

Answer 720

Ca2+

Question 721

What are the 3 forms of cell death?

Answer 721

Necrosis, apoptosis, and autophagic

Question 722

When does autophagic death occur?

Answer 722

If apoptosis is blocked or defective

Question 723

Cell death: Necrosis or Apoptosis???

Process is uncontrolled

Answer 723

Necrosis

Question 724

Cell death: Necrosis or Apoptosis???

Process is genetically programmed

Answer 724

Apoptosis

Question 725

Cell death: Necrosis or Apoptosis???

Cell enlarges and swells

Answer 725

Necrosis

Question 726

Cell death: Necrosis or Apoptosis???

Cell is reduced and shrinks

Answer 726

Apoptosis

Question 727

Cell death: Necrosis or Apoptosis???

Nucleus pyknosis –> karyolysis

Answer 727

Necrosis

Question 728

Cell death: Necrosis or Apoptosis???

Nucleus fragmentation into nucleosome sized fragments

Answer 728

Apoptosis

Question 729

Cell death: Necrosis or Apoptosis???

Plasma membrane is disrupted

Answer 729

Necrosis

Question 730

Cell death: Necrosis or Apoptosis???

Plasma membrane is intact; yet altered structure can occur (especially orientation of lipids)

Answer 730

Apoptosis

Question 731

Cell death: Necrosis or Apoptosis???

Cell contents undergo enzymatic digestion and may leak out of cell

Answer 731

Necrosis

Question 732

Cell death: Necrosis or Apoptosis???

Cell contents are intact. andmay be released in apoptotic bodies

Answer 732

Apoptosis

Question 733

Cell death: Necrosis or Apoptosis???

Adjacent inflammation frequently occurs

Answer 733

Necrosis

Question 734

Cell death: Necrosis or Apoptosis???

Adjacent inflammation does not occur

Answer 734

Apoptosis

Question 735

In adults, billions of cells die each hour. in tissues such as the ___ and ____ and are replaced by new cells.

Answer 735

Intestine and bone marrow

Question 736

The programmed destruction. ofcells during ____ is crucial to normal growth and development.

Answer 736

Embryogenesis

Question 737

DNA damage by _____, ____, and ______ will stimulate apoptosis if the insult is mild. Larger does of the same stimuli may lead to necrosis.

Answer 737

radiation, cytotoxic anticancer drugs, hypoxia

Question 738

What 3 neurodegenerative diseases cause accumulation. of misfolded proteins that lead to apoptosis?

Answer 738

Alzheimer’s, Huntington’s and Parkinson’s

Question 739

What are the main biochemical features of apoptosis?

Answer 739

1. activation. of caspases
2. cell components break into fragments
3. membrane alteration. and recognition by phagocytes

Question 740

What 2 families of proteins are key regulators of apoptosis?

Answer 740

Caspases and B-cell lymphoma proteins

Question 741

What are the initiator caspases?

Answer 741

CAS-2, -8,-9, -10

Question 742

What happens after initiator caspases are activated?

Answer 742

Initiator caspases dimerize and undergo proteolytic cleavage from a procaspase to the active caspase

Question 743

What are the effector (executioner) caspases?

Answer 743

CAS-3, -7

Question 744

How are effector caspases activated?

Answer 744

By the proteolytic attack of initiator caspases

Question 745

What. isthe major mechanism of apoptosis in all mammalian cells?

Answer 745

The mitochondiral pathway

Question 746

Apoptosis (Mitochondrial Path): Damage to mitochondria by ____ or ____ result. in the opening of large pores (called ____ channels) in the mitochondrial inner membrane.

Answer 746

reactive oxygen species (ROS); increases. in intracellular Ca2+; Bax/Bak channels

Question 747

Apoptosis (Mitochondrial Path): What resides in the cytoplasm and mitochondrial membranes that keeps Bax/Bak in check in normal healthy cells?

Answer 747

Bcl-2

Question 748

Apoptosis (Mitochondrial Path): After the mitochondria is damaged and pores are opened, what happens?

Answer 748

Cytochrome C and other proteins leak through the channels; mitochondria swell and may rupture

Question 749

Apoptosis (Mitochondrial Path): The _____ activates caspase-9 and commits the cell to apoptosis.

Answer 749

apoptosome

Question 750

Apoptosis (Death Receptor-Initiated): Extracellular signals bind to. a________ receptor.

Answer 750

trimeric transmembrane death receptor

Question 751

Apoptosis (Death Receptor-Initiated): The cytosolic portion of the death receptor has a death domain that recruits what?

Answer 751

Several molecules of procaspase-8

Question 752

Apoptosis (Death Receptor-Initiated): The recruited procaspase-8 aggregate undergoes autoproteolytic cleavage releasing ______.

Answer 752

active caspase-8

Question 753

Apoptosis (Executioner [death] Path):
Caspase-9 from. the____ path and caspase-8 from the ____ path converge upon executioner caspases __ and ___.

Answer 753

intrinsic; extrinsic; -3 and -7

Question 754

What do executioner caspases do?

Answer 754

They are proteolytic enzymes that degrade cellular components - especially. the nucleus- into small fragments

Question 755

What engulfs and processed apoptotic bodies?

Answer 755

Phagocytes

Question 756

How quickly does phagocytosis of apoptoic cells occur?

Answer 756

Within minutes (so it does it w/o leaving a trace and w/o causing inflammation)

Question 757

What. is signal for phagocytes to engulf the cells during apoptosis?

Answer 757

The phosphatidylserine phospholipid that is flipped to the outer leaflet of the membrane by caspases

Question 758

Which protein keeps mitochondrial Bax/Bak pores in check. in healthy cells?

Answer 758

Bcl-2

Question 759

Do most chemo durgs cause necrosis or apoptosis?

Answer 759

Apoptosis

Question 760

What type. of cell digests apoptotic bodies?

Answer 760

Phagocytes

Question 761

Intrinsic Apoptic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Apoptosome activates caspase-9

Answer 761

Intrinsic

Question 762

Intrinsic Apoptic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Death pathway

Answer 762

Execution

Question 763

Intrinsic Apoptic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Caspase-8

Answer 763

Extrinsic

Question 764

Intrinsic Apoptotic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Cell components. are packed into bite-sized apoptotic bodies

Answer 764

Execution

Question 765

Intrinsic Apoptotic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Mitochondria initiate

Answer 765

Intrinsic

Question 766

Intrinsic Apoptotic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Death Receptors initiate

Answer 766

Extrinsic

Question 767

Intrinsic Apoptotic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Caspase-3 and Caspase-7

Answer 767

Execution

Question 768

Intrinsic Apoptotic pathway OR extrinsic apoptotic pathway OR execution apoptotic pathway???

Bax/Bak channel

Answer 768

Intrinsic

Question 769

In the presynaptic nerve terminal, opioid-activated G protein βᵞ subunits block:
a. voltage-gated Ca2+ channels
b. voltage-gated Na channels
c. voltage-gated K+ channels
d. voltage-gated Cl- channels

Answer 769

A - Ca2+ channels

Question 770

B1 adrenoreceptor stimulation of cardiac myocytes produces positive chronotropic, dromotropic, inotropic, and lustiropic effects by ____ mediated signal transduction paths.

Answer 770

cAMP

Question 771

Many signals. at endothelial cells lead to the production of ____ and ___

Answer 771

NO and vasodilation

Question 772

Opioids exert _____ synaptic inhibitory responses in neurons through _____ receptor signal transduction paths.

Answer 772

pre and post; G protein-coupled

Question 773

What plays a key role. inwater regulation at the terminal nephron?

Answer 773

Vasopressin (Arginine Vasopressin [AVP]) and ADH

Question 774

What. is the sole enzyme for terminating cyclic nucleotide signals?

Answer 774

Cyclic nucleotide phosphodiesterases (PDE)

Question 775

Positive inotropy = ____

Answer 775

contractility

Question 776

Positive lusitropy = ______

Answer 776

relaxation

Question 777

Positive chronotropy = _____

Answer 777

HR

Question 778

Positive dromotropy = ______

Answer 778

conduction velocity

Question 779

Stimulation of B1 G protein-coupled receptors on cardiac myocytes activates ____ and increases intracellular ___.

Answer 779

adenylyl cyclase; cAMP

Question 780

After B1 stimulation, High levels of cAMP activate ____

Answer 780

protein kinase A (PKA)

Question 781

The medications, ___, ___, ___ and ____ donate NO directly to vascular smooth muscle cells, leading to relaxation and vasodilations.

Answer 781

Nitroglycerin, sodium nitroprusside, and isosorbide dinitrate

Question 782

What are the 4 families of opioid receptors?

Answer 782

1. Mu
2. Delta
3. Kappa
4. Nocicpetin

Question 783

Opioids: In ___synpatic neurons, Gβᵞ subunits block voltage-gated Ca2+ channels.

Answer 783

Pre

Question 784

Vasopressin plays a role in BP control at what 2 tissues?

Answer 784

Blood vessels and nephrons

Question 785

Vasopressin binds to ____ receptors on the basolateral membrane, activating the heterotrimeric G_ protein.

Answer 785

g protein-coupled V2; S

Question 786

PKA activation from Vasopressin does what?

Answer 786

Phosphorylates the water channel aquaporin 2 and activates transport. and fusion (exocytosis) of aquaporin-containing vesicles into the apical membrane

Question 787

Vasopressin: Increased APQ2 in the apical membrane _____ water reabsorption.

Answer 787

Increases

Question 788

Vasopressin binds to ___ receptors on vascular smooth muscle.

Answer 788

V1

Question 789

What. is a phosphodiesterase?

Answer 789

A hydrolase that breaks a phophodiester bond

Question 790

When does a phosphodiester bond happen?

Answer 790

When 2 hydroxyl groups of phosphoric acid (H3PO4) react w/ 2 hydroxyl groups attached to carbons to form 2 ester bonds

Question 791

______ form the backbone of DNA and RNA.

Answer 791

Phosphodiester bonds

Question 792

How many families of phosphodiesterases are there?

Answer 792

11

Question 793

PDE__ is nonselective for cAMP and cGMP, but binds to cAMP w/ 10x the affinity of cGMP binding.

Answer 793

3

Question 794

Where is PDE3 found?

Answer 794

Heart, vascular and placental smooth muscle, and tissues important in energy homeostasis (liver, pancreatic beta cells, adipocytes)

Question 795

Name 2 selective PDE3 inhibitors.

Answer 795

Milrinone and (in)amrinone

Question 796

T/F: 2nd messengers are tissue specific.

Answer 796

True

Question 797

PDE3 inhibitors ___ cAMP levels

Answer 797

increase

Question 798

What are the outcomes of PDE3 inhibitors?

Answer 798

Positive chronotropy, dromotropy, inotropy, and lustiropy & vasodilation

Question 799

What is Milrinone used for?

Answer 799

PHTN, cerebral vasospasm after aneurysmal subarachnoid hemorrhage, neonatal septic shock

Question 800

How is milrinone eliminated?

Answer 800

REnal excretion

Question 801

PDE__ is cGMP selective.

Answer 801

PDE5

Question 802

Where is PDE5 found? Where. isthe highest concentration?

Answer 802

tissues throughout the body;
Corpus cavernosus (penis & clitoris), vascular smooth muscle, and PLT

Question 803

Name 3 PDE5 inhibitors.

Answer 803

Sildenafil, Vardenafil, Tadalafil

Question 804

What are PDE5 inhibitors used for?

Answer 804

Erectile dysfunction, PHTN, high-altitude sickness, memory dysfunction

Question 805

How are PDE5 inhibitors metabolzied?

Answer 805

by CYP450 in liver

Question 806

PDE__ is cAMP selective.

Answer 806

4

Question 807

What does PDE4 do?

Answer 807

MOdulates B2-adrenergic responses in pulmonary smooth muscle

Question 808

Name 1 PDE4 med. What is it used for?

Answer 808

Roflumilast; COPD

Question 809

What are weak, nonselective inhibitors of PDE?

Answer 809

Methylxanthines (caffeine and theopylline)

Question 810

PDE3, PDE4, or PDE5???

Nonselective for cAMP and cGMP

Answer 810

3

Question 811

PDE3, PDE4, or PDE5???

cAMP selective

Answer 811

4

Question 812

PDE3, PDE4, or PDE5???

Milrinone is. aninhibitor

Answer 812

3

Question 813

PDE3, PDE4, or PDE5???

Inhibitors. are metabolized by CYP450 3A4

Answer 813

5

Question 814

PDE3, PDE4, or PDE5???

Sildenafil is an inhibitor

Answer 814

5

Question 815

PDE3, PDE4, or PDE5???

cGMP selective

Answer 815

5

Question 816

PDE3, PDE4, or PDE5???

Inhibitors are called inodilators

Answer 816

3

Question 817

PDE3, PDE4, or PDE5???

Roflumilast is an inhbiitor

Answer 817

4

Question 818

PDE3, PDE4, or PDE5???

Modulates B2 responses in pulmonary smooth muscle

Answer 818

4

Question 819

Inhibition. of SRCA2 is relieved. by phosphorylation of?

Answer 819

Phospholamban

Question 820

Endothelial nitric oxide synthase (eNOS) is activated by?

Answer 820

Ca2+CaM complex

Question 821

Water reabsorption in principal cells of the collecting duct is increased by the insertion of what protein into the apical membrane?

Answer 821

Aquaporin 2 (APQ2)

Question 822

What are the synonyms for Vasopressin?

Answer 822

• arginine vasopressin (AVP)
• antidiuretic hormone (ADH)

Question 823

Which is NOT a division of the ANS?
A. sympathetic
B. somatic
C. parasympathetic
D. enteric

Answer 823

B

Question 824

The visceral nervous system is synonymous with. the ____ nervous system.

Answer 824

autonomic

Question 825

What. arethe 3 divisions of the ANS?

Answer 825

sympathetic nervous system, parasympathetic nervous system, and enteric nervous system

Question 826

Where does the ANS proide neural control to?Where does it not?

Answer 826

All parts of the body except skeletal muscle

Question 827

____ nervous system is a major player. in homeostasis.

Answer 827

Autonomic

Question 828

Central nervous system = ____ + _____

Answer 828

brain + spinal cord

Question 829

Peripheral nervous system = ___ + ____

Answer 829

12 pairs of CN + 31 pairs. of spinal nerves

Question 830

Voluntary control of skeletal muscle is the _____

Answer 830

somatic

Question 831

Involuntary control of glands and smooth muscle is the ____

Answer 831

autonomic

Question 832

Why is CN2 part of the CNS structuarlly?

Answer 832

It is covered in 3 meningeal layers

Question 833

What do somatic nervers innervate?

Answer 833

Musculoskeletal strucutres and sensory organs of the skin

Question 834

What do autonomic nerves innervate?

Answer 834

Smooth muscle, cardiac muscle, and glands

Question 835

____ results in the absence of autonomic tone to a particular organ.

Answer 835

Denervation

Question 836

Which anatomic part of the nervous system is surrounded and covered by the meninges?

Answer 836

CNS

Question 837

Which type of muscle does NOT receive ANS signals?

Answer 837

Skeletal muscle

Question 838

Sympathetic or Parasympathetic???

Miosis

Answer 838

Parasympathetic

Question 839

Sympathetic or Parasympathetic???

Mass Discharge

Answer 839

Sympathetic

Question 840

Sympathetic or Parasympathetic???

Artery tone

Answer 840

Sympathetic

Question 841

Sympathetic or Parasympathetic???

Accommodation. inthe eye

Answer 841

Parasympathetic

Question 842

What are the 3 forms extracellular signals take?

Answer 842

1. chemical
2. electrical
3. mechanical

Question 843

What are thh 3 major categories of membrane-bound receptors?

Answer 843

1. Ion channels
2. G protein-coupled receptors
3. Enzyme-linked receptors

Question 844

Where are intracellular receptors located?

Answer 844

The cytoplasm or nucleoplasm

Question 845

____ is. theprocess by whihc a cell converts this extracellular signal into an intracellular response.

Answer 845

Signal transduction

Question 846

T/F: An ion channel is open or closed.

Answer 846

True

Question 847

What. are the 2 ways in which a GPCR can work?

Answer 847

1. opening or closing an ion channel
2. activating or inhibiting enzyme inside the cell

Question 848

When an enzyme-linked receptor is at rest, the catalytic domain is inactive. oractive?

Answer 848

Inactive

Question 849

The insulin receptor in skeletal muscle being linked to an enzyme called tyrosine kinase is an example. of ______ receptors.

Answer 849

enzyme-linked

Question 850

Steroids bind to receptors in the ____. Ths is an example of ____ receptors.

Answer 850

cytoplasm; intracellular

Question 851

Thyroid hormones bind to receptors in the ____. Ths is an example of ____ receptors.

Answer 851

nucleus; intracellular

Question 852

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

B1 Receptor

Answer 852

GPCR

Question 853

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Alpha or beta-gamma subunit opens or closes an ion channel

Answer 853

GPCR

Question 854

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Thyroid hormone receptor

Answer 854

Intracellular

Question 855

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Signal diffuses through membrane

Answer 855

Intracellular

Question 856

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Ligand binding to receptor activates catalytic domain

Answer 856

Enzyme

Question 857

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Substance flows along concentration gradient

Answer 857

Ion channel

Question 858

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Located in cytoplasm of nucleoplasm

Answer 858

Intracellular

Question 859

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Voltage gated potassium channel

Answer 859

Ion channel

Question 860

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Insulin receptor

Answer 860

Enzyme linked

Question 861

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Channel opens or closes

Answer 861

ion channels

Question 862

Ion channel, GPCR, Enzyme-linked, or Intracellular?????

Activates or inhibits an intracellular enzyme

Answer 862

GPCR

Question 863

Which is NOT a second messenger?
a. calcium
b. cyclic adenosine monophosphate
c. inositol triphosphate
d. glutamate

Answer 863

D

Question 864

Name the signaling sequence of GPCRs:

Answer 864

1st messenger (ligand) –> GPCR –> Effector –> 2nd messenger –> cellular response

Question 865

What 3 subunits are. inteh G protein component of GPCR?

Answer 865

alpha, beta, gamma

Question 866

What activates. theG protein?

Answer 866

The ligand-receptor interaction

Question 867

What is the function of an effector?

Answer 867

To activate or inhibit second messengers

Question 868

The intracellular response to second messengers is ___ specific.

Answer 868

Tissue

Question 869

Name 5 2nd messengers.

Answer 869

1. cAMP
2. cGMP
3. Inositol triphosphate (IP3)
4. Diacylgylcerol (DAG)
5. Calcium Ion (CA2+)

Question 870

An example. of an endogenous ligand is a ____ or _____.

Answer 870

NT or hormone

Question 871

A _____ binds to the GPCR.

Answer 871

Ligand

Question 872

Where does the receptor portion of the GPRC lie?

Answer 872

Outside the cell membrane

Question 873

Where does the G protein reside?

Answer 873

Inside the cell membrane

Question 874

What types of G-proteins turn on effectors?

Answer 874

Gs and Gq (these are stimulatory)

Question 875

What types of G-proteins turn off an effectors?

Answer 875

Gi

Question 876

What activates. a G-protein?

Answer 876

The ligand-receptor interaction

Question 877

What happens when the G-protein is activated?

Answer 877

The alpha subunit dissociates from the beta and gamma subunits

Question 878

When does the alpha subunit rejoin the beta and gamma subunits of a G-protein?

Answer 878

When the ligand unbinds from the receptor

Question 879

What is the purpose of the effector of GPCR?

Answer 879

To produce or activate the 2nd messenger

Question 880

Enzymatic effectors (that activate/produce the 2nd messenger) include _____ and _______.

Answer 880

adenylate cyclase and phospholipase C

Question 881

Ion channel effectors (that activate the 2nd messenger) include _____ and ________, at the _____.

Answer 881

GABA-a receptors and M2 receptors. at the SA node

Question 882

What process allows a single molecule to initiate a process that activates a large number of physiologic changes - each step progressively increasing the magnitude of response? What system allows for this process?

Answer 882

Signal amplification; Second messenger system

Question 883

The second messenger modulates a network of enzymatic activity, including ____ and ____.

Answer 883

phosphatases and protein kinases

Question 884

Which component of the GPCR signaling sequence allows for amplification?

Answer 884

second messenger

Question 885

Stimulation of which receptors increases phospholipase C activity? (select 2)
a. Alpha 1
b. vasopressin 1
c. beta-1
d. muscarinic 2

Answer 885

A and B

Question 886

Gs alpha subunits stimulate what?

Answer 886

adenylate cyclase

Question 887

What does Gs alpha stimulation promote?

Answer 887

Increased cAMP levels

Question 888

Gi alpha subunits inhibit what?

Answer 888

Adenylate cyclase

Question 889

What does Gi inhibition result in?

Answer 889

decreased cAMP levels

Question 890

Gq alpha subunits activate what? And what does this cause?

Answer 890

Phospholipase C; increased IP3, DAG, and Ca2+

Question 891

Gq –> Increased ________ effector

Answer 891

Phospholipase C

Question 892

Gi –> Decreased ________ effector

Answer 892

Adenylate Cyclase

Question 893

Gs –> Increased ________ effector

Answer 893

Adenylate Cyclase

Question 894

Gs - second messenger??

Answer 894

increased cAMP

Question 895

Gi - second messenger??

Answer 895

Decreased cAMP

Question 896

Gq - second messenger??

Answer 896

Increased IP3, DAG, Ca2+

Question 897

What is the signal transduction of Alpha 1? (Gq, Gi, or Gs??)

Answer 897

Gq

Question 898

What is the signal transduction of Alpha 2? (Gq, Gi, or Gs??)

Answer 898

Gi

Question 899

What is the signal transduction of Beta 1? (Gq, Gi, or Gs??)

Answer 899

Gs

Question 900

What is the signal transduction of Beta 2? (Gq, Gi, or Gs??)

Answer 900

Gs

Question 901

What is the signal transduction of Beta 3? (Gq, Gi, or Gs??)

Answer 901

Gs

Question 902

What is the signal transduction of Nicotinic Receptors?

Answer 902

Ion channels

Question 903

What is the signal transduction of M1? (Gq, Gi, or Gs??)

Answer 903

Gq (1,3,5 are all Gq)

Question 904

What is the signal transduction of M3? (Gq, Gi, or Gs??)

Answer 904

Gq (1,3,5 are all Gq)

Question 905

What is the signal transduction of M5? (Gq, Gi, or Gs??)

Answer 905

Gq (1,3,5 are all Gq)

Question 906

What is the signal transduction of M2? (Gq, Gi, or Gs??)

Answer 906

Gi (2, 4 are Gi)

Question 907

What is the signal transduction of M4? (Gq, Gi, or Gs??)

Answer 907

Gi (2 & 4 are Gi)

Question 908

What is the signal transduction of Dopamine 1 (postsynaptic)? (Gq, Gi, or Gs??)

Answer 908

Gs

Question 909

What is the signal transduction of Dopamine 2 (presynaptic)? (Gq, Gi, or Gs??)

Answer 909

Gi

Question 910

What is the signal transduction of Vasopressin 1 (vasculature)? (Gq, Gi, or Gs??)

Answer 910

Gq

Question 911

What is the signal transduction of Vasopressin 2 (renal tubules)? (Gq, Gi, or Gs??)

Answer 911

Gs

Question 912

What is the signal transduction of Histamine 1? (Gq, Gi, or Gs??)

Answer 912

Gq

Question 913

What is the signal transduction of Histamine 2? (Gq, Gi, or Gs??)

Answer 913

Gs

Question 914

Match each receptor with its physiologic action?
A2 M3 B2 B1

Increased automaticity
Coronary vasoconstriction
Skeletal muscle vasodilation
Bronchoconstriction

Answer 914

Increased automaticity - B1
Coronary vasoconstriction - A2
Skeletal muscle vasodilation - B2
Bronchoconstriction - M3

Question 915

What does parasympathetic nervous stimulation of M2 receptors cause?

Answer 915

Decreased rate, contraction, and conduction velocity

Question 916

______ nervous system of B1 receptors. atthe heart causes increased rate, contraction, and conduction velocity.

Answer 916

Sympathetic

Question 917

Do arteries and veins receive PNS input?

Answer 917

No

Question 918

Arteries and veins receive no PNS input, in general. What are the excpetions?

Answer 918

Coronary vessels (vasodilation) and cerebral vessels (receptor-specific vasodilation or vasoconstriction)

Question 919

SNS stimulation of most arterial vessels causes ______ via what receptors?

Answer 919

vasoconstriction; A1

Question 920

SNS activation of ___ receptors on veins produces venoconstriction.

Answer 920

A2

Question 921

SNS stimulation of B2 receptors on most arterial vessels produces what?

Answer 921

vasodilation

Question 922

What is the PNS effect upon airway smooth muscle and through what receptor?

Answer 922

Contraction of airway smooth muscle; M3

Question 923

SNS activity produces ____ of airway smooth muscle

Answer 923

relaxation (b2 receptors)

Question 924

SNS:
Effector - Heart
Receptor - ______

Answer 924

B1

Question 925

SNS:
Effector - Lungs
Receptor - ______

Answer 925

B2

Question 926

SNS:
Effector - GI Tract
Receptor - ______

Answer 926

A1

Question 927

SNS:
Effector - Glands
Receptor - ______

Answer 927

A1

Question 928

SNS:
Effector - Urinary Tract
Receptor - ______

Answer 928

A1, B2

Question 929

SNS:
Effector - Skin
Receptor - ______

Answer 929

A1

Question 930

SNS:
Effector - Skeletal Muscle
Receptor - ______

Answer 930

B2

Question 931

SNS:
Effector - Pupils
Receptor - ______

Answer 931

A1

Question 932

SNS:
Effector - Heart
Receptor - B1
Effect - ________

Answer 932

Positive inotropic, chronotropic, and dromotropic effect

Question 933

SNS:
Effector - Lungs
Receptor - B2
Effect - ________

Answer 933

Bronchodilation

Question 934

SNS:
Effector - GI Tract
Receptor - A1
Effect - ________

Answer 934

Vasoconstriction; Sphincter contraction

Question 935

SNS:
Effector - Glands
Receptor - A1
Effect - ________

Answer 935

Increased sweating
Decreased pancreatic activity

Question 936

SNS:
Effector - Urinary Tract
Receptor - A1, B2
Effect - ________

Answer 936

Bladder sphincter contraction
Increased renin secretion

Question 937

SNS:
Effector - Skin
Receptor - A1
Effect - ________

Answer 937

Vasoconstriction

Question 938

SNS:
Effector - Skeletal Muscle
Receptor - B2
Effect - ________

Answer 938

Vasodilation

Question 939

SNS:
Effector - Pupils
Receptor - A1
Effect - ________

Answer 939

Dilation

Question 940

PNS:
Effector - Heart
Receptor - ______

Answer 940

M2

Question 941

PNS:
Effector - Lungs
Receptor - ______

Answer 941

M3

Question 942

PNS:
Effector - GI Tract
Receptor - ______

Answer 942

M3

Question 943

PNS:
Effector - Glands
Receptor - ______

Answer 943

M1, M3

Question 944

PNS:
Effector - Urinary Tract
Receptor - ______

Answer 944

M3

Question 945

PNS:
Effector - Pupils
Receptor - ______

Answer 945

M3

Question 946

PNS:
Effector - Heart
Receptor - M2
Effect - ______

Answer 946

Negative inotropic, chronotropic, and dromotropic effect

Question 947

PNS:
Effector - Lungs
Receptor - M3
Effect - ______

Answer 947

Bronchconstriction
Increased galnd secretion

Question 948

PNS:
Effector - GI Tract
Receptor - M3
Effect - ______

Answer 948

Increased motility
Sphincter relaxation
Increased gland secretion

Question 949

PNS:
Effector - Glands
Receptor - M1, M3
Effect - ______

Answer 949

Increased salivation
Increased lacrimation
Increased pancreatic activity

Question 950

PNS:
Effector - Urinary Tract
Receptor - M3
Effect - ______

Answer 950

Bladder sphincter relaxation

Question 951

PNS:
Effector - Pupils
Receptor - M3
Effect - ______

Answer 951

Constriction