Chapter 6: Nervous System & Synaptic Transmission Flashcards
Test 2
1
Q
What are the different nervous systems?
A
Peripheral
Central
Somatic
Autonomic
Sympathetic
Parasympathetic
Enteric
2
Q
What does Afferent mean?
A
Towards the CNS
Up
Sensory/Pain
3
Q
What does Efferent mean?
A
Away from the CNS
Down
Motor
4
Q
What does CNS consist of?
A
Brain
Spinal cord
Cranial nerve 2
5
Q
What does the PNS consist of?
A
neurons that extend outward from the brain and spinal cord
6
Q
What are somatic sensory receptors?
A
Touch, pressure, pain, temperature sensors
7
Q
What are visceral sensory receptors?
A
monitors internal organs: cvs, respiratory, digestive, etc
8
Q
What are special sensory receptors?
A
provide sensations of smell, taste, vision, balance, hearing
9
Q
What is the CNS responsible for?
A
Higher order of processing/functioning
10
Q
Describe the somatic nervous system
A
Consciously controls skeletal muscle
11
Q
Describe the autonomic nervous system
A
Includes Parasympathetic, sympathetic, and enteric nervous systems
Unconsciously controls cardiac muscle, smooth muscle, and glands
12
Q
Describe the Enteric Nervous System
A
“Gut feeling”
Mulitple layers of neurons controlling GI functions
Mainly under parasympathetic control
Has some sympathetic functioning
13
Q
Describe the Parasympathetic nervous system
A
Mediates “rest and digest” responses
shunts blood to: endocrine, GI, urogenital
decrease HR and increasing digestion
Brings you back down to normal (conserves energy)
14
Q
Describe the Sympathetic nervous system
A
Mediates “fight-or-flight” responses
Increasing HR/BP/RR(dilates bronchioles)
Shunts blood from GI tract to Skeletal/Smooth muscle
15
Q
Which nervous system has sensory input?
A
Somatic nervous system
16
Q
What is another name for the cell body of a motor neuron?
A
Nuclei
17
Q
Where is the nuclei of the somatic neuron located?
A
Ventral horn of grey matter in the spinal cord
18
Q
Reflex arc only goes to the ______ and activates________
A
spinal cord
Efferent divisons
19
Q
What are the collection of cell bodies of neurons called in the autonomic nervous system?
A
ganglia
20
Q
Where are ganglia located?
A
outside of the spinal cord
21
Q
What is an individual neuron cell body in the Autonomic NS called?
A
Ganglionic neuron
22
Q
Define a nervous system
A
Several layers of neurons interacting
23
Q
NS =
A
Nervous system
24
Q
What NS is primative in nature?
A
Enteric NS
25
Up to _____ of blood can be shunted during a sympathetic response
75%
26
T/F: Sympathetic NS is continuously stimulated when scared
T
27
What is an ergotropic response?
Movement related to the "fight or flight" response
28
What happens during the fight or flight response
A combo of:
Epinephrine being released from adrenal glands
Norepinephrine being released from CNS
29
How many times is the Parasympathetic Response activated?
1x
then it brings us back to normal
30
What is trophotropic response?
Rest that is leading to growth
31
What 2 nervous systems balance each other?
Sympathetic and Parasympathetic
32
Discuss the differences in “fight-or-flight” and “rest-and-digest” mode.
“fight-or-flight”:
Sympathetic NS
Shunts blood to heart and skeletal muscles
Increases HR/BP/RR
Ergotropic response
RUN AWAY
“rest-and-digest”
Parasympathetic NS
Shunts blood to endocrine, GI, urogenita
Increase GI, decrease HR
Trophotropic response
Leads to growth
33
What is cranial nerve X
10
Vagus nerve (heart)
34
Where is the Sympathetic NS located?
Thoracolumbar
T1 - L2
35
Describe the Pre/Post ganglionic fibers in the sympathetic NS
Pre: Short; terminate in the ganglia paravertebral chains; close to spinal cord
Post: Long; terminates on affected tissue/organ
36
Describe the Pre/Post ganglionic fibers in the parasympathetic NS
Pre: Long; leaves CNS through cranial nerves and sacral spinal roots
Post: Short; terminate on organ
37
Where is the parasympathetic NS located?
Craniosacral
Cranial Nerves III, VII, IX, X
S3 - S4
38
What is a chain ganglia?
"paravertebral ganglia"
series of interconnected ganglia on either side of the spinal cord
39
What does a chain ganglia do?
allows signals to travel to reach targets at different levels (organs/tissues), which is essential during stress or emergency situations—such as rapidly increasing heart rate and dilating the pupils.
40
What NS is a chain ganglia in?
Sympathetic
41
Where does the ganglia in the parasympathetic NS?
In the visceral effector organs
42
What type of neuron does the Autonomic NS use?
A 2-neuron chain
1st neuron (preganglionic) is lightly myelinated
2nd neuron (post) extends to effector organ
43
What does the preganglionic fibers release in the autonomic NS?
Ach
44
What does the postganglionic fibers release in the autonomic NS?
Ach or Norepinephrine
depending on whether we are inhibiting or stimulating effect
45
Define Sympathomimetic
Drug that memics the affects of Norepinephrine in the Sympathetic NS
46
How do direct acting Sympathomimetic work?
Ex)
Directly bind to the receptor
Ex) epi, isoproterenol, albuterol
47
How do indirect Sympathomimetic work?
Ex)
Dont bind to receptor
Influx of norepinephine for a longer period of time in the synapse
Ex) Ephedrine, amphetamines
48
What does inotropic affect?
Contractility
48
What does chronotropic affect?
Heart rate
49
What does Sympathomimetic do?
Vasoconstriction
Increace Inotropic/chronotropic effects
decrease bronciole tone
decrease uterine muscle tone
50
What is a Sympatholytics?
Inhibits the sympathetic NS effects
51
PNS =
parasympathetic nervous system
52
SNS =
sympathetic nervous system
53
CNS =
Central nervous system
54
What are the Cholinergic receptor?
Muscarinic
Nicotinic
55
What are the Adrenergic receptors?
Alpha
Beta
Dopamine
56
How many cholinoreceptors subtypes do we have?
5 muscarinic
2 nicotinic
57
Which muscarinic subtypes are inhibitory?
2, 4
58
Which muscarinic subtypes are excitatory?
1,3,5
59
Where are the nicotinic subtypes located?
peripheries
N(n): neuronal at the ganglion
N(m): muscle at skeletal muscle end plates
60
How many Adrenoreceptor subtypes are there?
2 Alpha
3 Beta
61
How many Dopamine subtypes are there? Where are they mostly located?
5
Brain, smooth muscle of the renal vascular bed, cvs
62
What type of receptor are the adrenergic receptors?
GPCRs
63
What does the A-1 receptor do?
Activates G(q) -----> activates phospholipase C -------> activates IP3
64
What does the A-2 receptor do?
Activates G(i) ---------> inhibits adenylate cyclase --------> decrease cAMP
65
What does B-1 and B-2 receptors do?
Activate G(s) -------> stimulates adenylate cyclase ---------> increases cAMP
66
Describe the Alpha-1 Receptor pathway when Norepinephrine binds to the receptor
1. G(q) is activated and attaches to Phospholipase C
2. Phospholipase C releases DAG and IP3
3. IP3 attaches to to the IP3 V-G Ca++ channel on the SR
4. The SR opens and allows Ca++ to flood into the cell.
** Also during depolarization of the cell, Ca++ will be able to come into the cell via diffusion through its respective ion channel**
5. MCLK (myosin chain light kinase) phosphoriates the Ca++ causing the muscle to contract
**DAG also activates Protein kinase C which inhibits MCLP which causes the muscle to contract**
6. MCLP (myosin chain light phosphatase) strips the phosphate to allow the muscle to relax
67
Where does the Beta-1 receptor work in the heart?
Cardiac Myocyte
68
Describe the pathway when Norepinephrine binds in the cardiac myocytes
1. NE is released from the SNS or exogenous NE binds to B-1 & B-2 receptor
2. Activates G(s) which attaches to adenylyl cyclase
3. adenylyl cyclase cycles ATP to cAMP which causes a phosphorylation cascade
4. active protein kinase depolarizes the cell wall to allow Ca++ into the cell through its ion channel down via diffusion
** Protein kinase also allows Ca++ out of the SR into the cell
5. A contraction occurs
69
What does the A-2 receptor do?
inhibits the reuptake of norepinephrine
acts as a negative feedback loop on the heart preventing the heart from continously beating fast and hard
70
Where are Alpha 1 receptors located?
Peripheries
71
B-1 and B-2 in the heart are _______
Stimulatory
72
B-2 in the peripheries is _______
inhibitory
73
Where are your L-type Ca++ channels?
Smooth muscle
74
_____ in the cardiac myocytes and in the peripheries have an _____ effect
B-2 receptors
opposite
75
What happens when NE binds to B-2-R in the periphery?
1. Activates G(s) which binds to adenylyl cyclase
2. cycles ATP into cAMP
3. cAMP inhibits MLCK whihch causes relaxation
76
What are your primary sympathetic receptors?
Alpha and Beta receptors
77
What are your parasympathetic receptors? What do they bind to?
Cholinergic
Ach
78
What type of receptor is your nicotinic-R?
Ion channel
79
How many types of nicotinic-R do we have? What are they?
3
Ganglionic
Skeletal
Neuronal
80
What does the the Muscarinuc 1, 3, and 5 receptors do?
Stimulatory
G(q)
Phopholipase C activation
81
What does the the Muscarinuc 2 and 4 receptors do?
inhibitory
G(i)
inhibit adendyly cyclase
82
Describe NANC Neurons
Non-adrenergic, non-cholinergic neurons
In the Enteric NS
Both sensory and motor
Different neurotransmitters released
Ex) Nitric oxide synthase (NOS), substance P
83
What does NE and Ach do in the abdominopelvic cavity?
NE: constriction of blood vessels
Ach: Dilation of blood vessels
84
What is Cardiovascular integration's primary variable?
Mean arterial pressure
85
What is Cardiovascular integration for?
Responses to MAP to induce homeostasis
86
In the Cardiovascular integration, describe the hormonal feedback loop
Uses renal blood flood in the kidneys to adjust BP
Renin - Angiotensin - Aldosterone - increase blood volum/etc
87
In the Cardiovascular integration, describe the autonomic feedback loop
Uses baroreceptors and the vasomotor center to adjust BP via the SNS or the PNS
88
What do baroreceptors do?
Respond to pressure on arteries
89
What does the vasomotor center do?
shuts down or increases the stimulus to the heart
90
What does angiotensin do?
Constrict blood vessels in the kidneys
91
Define heteroreceptor
receptor on that neuron that is not responding to something that is being released.
Ex. If neuron is releaseing Ach. And I have a A-1 receptor. That receptor is a heteroreceptor.
92
Define autoreceptor
receptor on that neuron that is responding to something that is being released
93
inhibitory =
negative feedback
94
excitatory =
positive feedback
95
which node sets the pace of the heart?
SA
96
How does the SNS effect the body?
SA node (B1/B2): Increase
Contractility (B1/B2): Increase
Skeletal (B1): Relax
Smooth (A1): Constrict
Bronchiole (B2): Dilate
97
How does the PNS effect the body?
SA node (M2): Decrease
Contractility (M2): Decrease
Smooth (M3): Relax
Bronchiole: Contract
98
In skeletal muscles, Alpha-adrenergic drugs causes the blood vessels to
vasoconstrict
99
In skeletal muscles, Beta-adrenergic drugs causes the blood vessels to
vasodilate
100
In skeletal muscles, cholinergic drugs causes the blood vessels to
vasodilate
101
In skeletal muscles, parasympathetic nerves causes the blood vessels to
vasodilate
102
skeletal muscles at rest take up _____ of circulaint blood
20%
103
What do NS do Alpha and Beta blockers block?
Sympathetic
104
What is Cholinomimetics?
Mimics Ach
105
PNS is primarily the ______ nerve
Vagus
106
The PNS Preganglionic fiber will always release what ligand?
Ach
107
The SNS Postganglionic fiber can release what ligands?
Norepinephrine
Dopamine
Ach
108
What is a synapse?
Connection between a neuron and a cell
Small gap in between where neurotransmitters are released and ligands can bond to receptors
109
What part of the neuron generates the AP?
Axon Hillock
110
What is the decision making park of the neuron?
Nucleus
111
What part of the neuron releases the neurotransmitter?
Synaptic boutons
112
Where are the syntapic boutons?
The synpatic terminal
113
Describe a telodendrion
The stem of the synaptic bouton
Needs ATP therefore Mitochondria is in synaptic bouton
114
What are the 3 types of synapse?
Chemical
Electical
En Passant
115
Describe Neurotransmitters
Released by presynpase
Used by receptors on post synapse
Will stay in the synapse if not degraded or reuptaked
116
hyperpolarization =
inhibition
117
depolarization =
excitation
118
What can happen after a neurotransmitter binds to a receptor?
The ION CHANNEL can open and the cell can become depolarized or hyperpolarized
or
the GPCR GP can dissociate and second messenger activity occurs
119
Whatis the fate of a neurotransmitter?
1. diffuses away from synapse
2. degraded by enzymes
3. uptake into pre synapse
4. uptake into surrounding tissues
120
What is an Ester?
R- C (== O) - R
121
What are the neurotransmitter classes?
Esters
Monoamines
Aminoacids
Purines
Peptides
Inorganic gases
122
In the neurotransmitter classes, what are considered Esters?
Ach
123
In the neurotransmitter classes, what are considered Monoamines?
NE
Serotonin
Dopamine
124
In the neurotransmitter classes, what are considered amino acids?
Glutamate
GABA
125
In the neurotransmitter classes, what are considered Purines?
Adenosine
ATP
126
In the neurotransmitter classes, what are considered Peptides?
Substance P (pain signaling)
Endorphins, enkephalins (pain control)
127
In the neurotransmitter classes, what are considered inroganic gases?
NO - nitric oxide
128
T/F: mAch-R are faster than nAch-R
F
129
Where is Ach located?
All skeletal muscle fibers
All preganglionic fibers
All PNS postganglionic fibers
130
Describe Monoamines
Amino acid derivatives
Found in the brain
Adrenergic/noradrengeric fibers
131
Dopamine =
pleasurable
132
Low levels of serotonin indicate
depression
133
What is the serotonin receptor called?
5-HT
134
Describe Glutamate:
Amino Acid
Most important EXCITATORY neurotransmittor in the brain
important for learning/memory
Receptors: AMPA (ion); NMDA (ion); Metabotropic (GPCR +ion)
135
Describe Glycine:
Amino Acid
Post synapse inhibition
136
What does Poison Strychnine do?
Blocks glycine receptor (inhibitory receptor in the brain) which results in fatal seizures
137
Describe GABA:
Gamma Amino Butyric Acid
MOST IMPORTANT inhibitory neurotransmitter in the brain
most anesthetics work by increasing GABA
138
Neutrotransmitters can be classified as what?
Inhibitory or Excitatory
139
Where do you get choline from?
Diet
140
Where do you get Acetate from?
Mitochondria
141
Where is Ach made?
cytoplasm of neuron
142
What enzyme creates Ach from Acetate (acetyl-CoA) and Choline?
Choline Acetyltransferase (ChAT)
143
What enzyme breaks down Ach?
acetylcholinesterase
144
How many Ach are in each vesicle?
1000 - 50,000
145
What is a CHT transporter?
Choline/Na+ Co-transporter
into neuron via facilitated diffusion
146
What is a VAT transporter?
transports Ach into the vesicle and H+ out
147
What is the full process for getting Ach into a vesicle?
CHT - ChAT - VAT
148
What are SNARE Complex?
Anchoring/Docking mechanism for the vesicles and membranes
149
Which SNARE complex are associated with the vesicle?
Syntaxin
SNAP-25
150
Which SNARE complex are associated with the membrane?
VAMP
vesicular associated membrane protein
151
Which SNARE complex are associated the actual facilitation of rapid exocytosis?
Synaptotagmin (Ca++ sensor)
152
What is Docking?
Ex) Putting Ach/Epi/etc... into a vesicle
153
What is MG and how is it treated?
Antibodies against nAch-R
-Neostigmines: blocks acetylcholinesterase which allows more Ach in the NMJ longer
154
What is the precursor to Dopa, Dopamine, NE, Epi?
Tyrosine
155
How does Adrenergic transmission work?
Very similar to cholinergic transmission
The VAT = VMAT **MOA is in the neuron**
NE has a NETransporter
156
List targets for drug action in the synapse and examples
1. Metyrosine - inhibits conversion of tyrosine
2. Reserpine - inhibits vesicle storage (VMAT)
3. Bretylium - guanthidine - inhibit release
4. Cocaine, tricycle antidepressants - inhibit NET
5. MAOI - inhibit NE degradation
6. Botox - cleaves SNAP
