Cellular communication 6

Question 1

The brain synthesizes its own histamine from

Answer 1

L-histidine (an amino acid)

Question 2

One major metabolite of histamine, _______________, can be measured in the urine to determine the amount of histamine that has been released systemically.

Answer 2

imidazole acetic acid

Question 3

What enzymatic reaction is present in ALL biogenic amine neurotransmitter biosynthesis?

Answer 3

decarboxylation

Question 4

Biogenic amine neurotransmitters are removed from the synaptic clefty by

Answer 4

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

Question 5

Adrenergic receptors are divided into three main classes with three subtypes each:

Answer 5

alpha 1
alpha 2
beta

Question 6

Serotonergic neurons play a vital role in

Answer 6

sleep & wakefulness
emotions
cognition
CV
respiratory
& intestinal activities

Question 7

Derangements of serotonergic pathways contribute to

Answer 7

anxiety
depression
mania
schizophrenia

Question 8

______________________________- is the target of antagonists that are used to treat postoperative or cancer-chemotherapy-induced nausea and vomiting

Answer 8

the ionotropic 5-HT3 serotonin receptor

Question 9

Histaminergic neurons play a role in

Answer 9

arousal and attention
memory
learning
mood

Question 10

L-tyrosine is present in all ______________ and can be synthesized from __________

Answer 10

food products; phenylalanine

Question 11

Tyrosine is converted into __________ by the rate limiting enzyme _____________-

Answer 11

dihydroxyphenylalanine (DOPA)
tyrosine hydroxylase

Question 12

Degeneration of dopaminergic neurons in the substantia nigra causes

Answer 12

Parkinson’s disease

Question 13

Overactive D2-like receptors are implicated in the pathogenesis of

Answer 13

schizophrenia

Question 14

Two major groups of adrenergic (Epi) neurons have been identified in the CNS:

Answer 14

the rostral ventrolateral medulla
the nucleus tractus solitarius

Question 15

In the peripheral nervous system, NE is released from most

Answer 15

postganglionic sympathetic neurons onto the target tissues

Question 16

In the peripheral nervous system, epinephrine is released from

Answer 16

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

Question 17

All adrenergic receptors are

Answer 17

metabotropic

Question 18

What are the alpha 1 subclasses?

Answer 18

alpha1A, alpha1B, alpha1D

Question 19

What are the alpha 2 subclasses?

Answer 19

alpha2A, alpha2B, alpha2C

Question 20

What are the beta subclasses?

Answer 20

b1, b2, b3

Question 21

The adrenergic classes are distinguished by their relative sensitivity to

Answer 21

isoproterenol

Question 22

Isoproterenol activates _____________receptors, whereas ______________ receptors are very poorly activated by isoproterenol.

Answer 22

beta-adrenergic receptors; alpha-adrenergic receptors

Question 23

Activation of presynaptic alpha-2 receptors results in _______________- of NE release

Answer 23

inhibition

Question 24

Three of the four main classes of serotonin receptors are metabotropic and include:

Answer 24

5HT1
5HT2
5HT4

Question 25

The brain cells synthesize their own histamine from the amino acid

Answer 25

L-histidine

Question 26

Histidine is ________ to form histamine

Answer 26

decarboxylated

Question 27

Histamine receptor subtypes are

Answer 27

metabotropic

Question 28

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

Answer 28

substantia nigra

Question 29

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

Answer 29

c. L-arginine

Question 30

ATP, ADP, and adenosine are __________neurotransmitters

Answer 30

purinergic

Question 31

Purinergic receptors are

Answer 31

both ionotropic (P2X family) and metabotropic (P1, & P2Y families)

Question 32

Most neuropeptides are _______ with other transmitters

Answer 32

co-released

Question 33

All neuropeptides act on ___________ receptors, and most often induce

Answer 33

metabotropic; alterations in the excitability of postsynaptic cells

Question 34

Nitric oxide is a universal intercellular messenger acting as both an

Answer 34

autocrine and paracrine signaling molecule

Question 35

Nitric oxide synthase (NOS) converts

Answer 35

L-arginine to L-citrulline and NO

Question 36

Many effects of NO are mediated locally by soluble

Answer 36

guanylyl cyclase which produces cGMP from GTP

Question 37

NO plays a role in

Answer 37

central sensitization to pain

Question 38

At body temperature, NO is a small, lipid-soluble _______

Answer 38

gas that easily permeates lipid membranes, "soaking" the surrounding tissue cells

Question 39

Conventional neurotransmitters are stored in _______- and released as

Answer 39

synaptic vessels; released as quanta by Ca2+ dependent exocytosis

Question 40

Nonconventional neurotransmitters cannot be stored in

Answer 40

vesicles and thus are synthesized and released on demand

Question 41

Purine & pyrimidine nucleotides are key elements in cell physiology because they have the follwoign roles:

Answer 41

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

Question 42

Purine bases are

Answer 42

adenine (A) and guanosine (G)

Question 43

Pyrimidine bases are

Answer 43

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

Question 44

A nucleotide is a molecule composed of a

Answer 44

5-carbon sugar (a pentose) a nitrogenous base & at least one phosphate group

Question 45

A nucleoside is a molecule composed of a

Answer 45

pentose and a nitrogenous base with no phosphate group

Question 46

Adenosine plays a role in the

Answer 46

sleep/wake state -increased promote sleep

Question 47

A strong increase in ______________ levels in the extracellular fluid is an emergency signal indicating an acute oxygen deficiency (stroke, angina pectoris, MI)

Answer 47

adenosine

Question 48

Purinergic neurotransmitters are metabolized to ____ to terminate effects.

Answer 48

5'AMP