Autonomic drug concepts

Question 1

what neurotransmitter is used in presynaptic neurons?

Answer 1

achetylcholine

Question 2

what neurotransmitter is used in postsynaptic PNS neurons?

Answer 2

acetylcholine

Question 3

what neurotransmitter is used in postsynaptic SNS neurons?

Answer 3

norepinephrine (or acetylcholine)

Question 4

what neurotransmitter is used in somatic neurons?

Answer 4

acetylcholine

Question 5

what neurotransmitter receptors are at SNS tissues?

Answer 5

adrenergic, muscarinic (sweat glands)

Question 6

what neurotransmitter receptors are at PNS tissues?

Answer 6

muscarinic

Question 7

what neurotransmitter receptors are at somatic tissues?

Answer 7

nicotinic

Question 8

which cranial nerves have parasympathetic neurons?

Answer 8

III (smooth muscles of the eye)
VII (lacrimal glands)
IX (salivary glands)
X (smooth muscles in abdominal + thoracic viscera)

Question 9

what receptors are at ANS synpases?

Answer 9

nicotinic neuronal

Question 10

what kind of receptors are muscarinic receptors?

Answer 10

GPCR

Question 11

what kind of receptors are nicotinic receptors?

Answer 11

ligand-gated ion channels (need 2 Ach molecules to open)

Question 12

where are M1 receptors?

Answer 12

CNS
autonomic ganglia
glands (secretion of gastric juice)
enteric nerves

Question 13

where are M2 receptors?

Answer 13

CNS
heart (slows heart rate and conduction at SA/AV nodes, and slows force of contraction)
smooth muscle
autonomic nerve terminals

Question 14

where are M3 receptors?

Answer 14

CNS
smooth muscle (contraction at iris, bronchi, GI tract)
glands
heart

Question 15

where are N_m receptors?

Answer 15

neuromuscular junction (opens Na/K channels for contraction)

Question 16

where are N_n receptors

Answer 16

autonomic ganglia
adrenal medulla (secretion of catecholamines)
CNS

Question 17

mechanism of action for M1,M3,M5 receptors (stimulatory)

Answer 17

G_q -> PLC -> PIP -> IP3 -> DAG -> PKC

Question 18

mechanism of action for M2,M4 receptors (inhibitory)

Answer 18

inhibition of adenylate cyclase -> decreased cAMP
activation of inward rectifying potassium channels so hyperpolarization
inhibition of neuronal calcium channels

Question 19

what are the effects of nicotine?

Answer 19

stimulation: sympathetic ganglia, parasympathetic ganglia, blockade of parasympathetic ganglia
adrenal medulla: epi release
supraoptic nucleus: release ADH
CNS: tremor and nausea

Question 20

what are the effects of nicotinic receptor antagonists

Answer 20

primarily: non-depolarizing (competitive) neuromuscular blockade

Question 21

what are the effects of non depolarizing blockers at low dose? at high dose?

Answer 21

low: blocks receptor
hi: enters pore of receptor; hard to reverse

Question 22

what are the effects of depolarizing blockers? (2 phases)

Answer 22

phase I: cause release, hard to repolarize

phase II: desensitization after repolarization

Question 23

where are endogenous catecholamines made?

Answer 23

in the sympathetic nerve endings and chromaffin cells of the adrenal medulla

Question 24

name the steps (starting at tyrosine) of catecholamine synthesis

Answer 24

tyrosine, DOPA, dopamine, norepinephrine, epinephrine

Question 25

where are alpha 1 receptors found?

Answer 25

VSMC, genitourinary SMC, intestinal SMC, heart, liver

Question 26

where are alpha 2 receptors found?

Answer 26

pancreatic beta cells, platelets, nerves, VSMCs

Question 27

what do alpha 2 agonists activate?

Answer 27

G_i for decreased adenylyl cyclase. inhibit some channels and inhibit release

Question 28

where are beta 1 receptors found?

Answer 28

heart (hi chronotropy and inotropy and AV node conduction velocity) renal JGA cells (more renin) G_s

Question 29

where are beta 2 receptors found?

Answer 29

``` smooth muscle (mostly pulmonary and peripheral; relaxation), skeletal muscle, liver (glycogenolysis) G_s ```

Question 30

where are beta 3 receptors found?

Answer 30

adipose (lipolysis)

Question 31

Which receptors does norepinephrine act on?

Answer 31

a1,a2,b1,b2,b3

Question 32

What is reflex bradycardia?

Answer 32

When baroreceptors sense an increase in the pressure, activates vagus nerve, and decreases HR via Ach release to M2 receptors

Question 33

Which receptors does epinephrine act on?

Answer 33

a1,a2,b1,b2,b3 | Higher beta effect at low doses, and vice versa

Question 34

How does dopamine cause vasodilation?

Answer 34

D2 receptors inhibit AC -> low cAMP

Question 35

What are the effects of dopamine?

Answer 35

``` Vasodilation low dose B1 effects high dose A1 effects (vasoconstrict) high dose ```

Question 36

two uses of a1 adrenergic agonists?

Answer 36

treatment of shock | topically in nasal decongestant

Question 37

difference between a1 and a2 receptors?

Answer 37

a1 is activating, a2 is inhibiting (inhibit adenylyl cyclase)

Question 38

use of a b1 selective agonist?

Answer 38

increase cardiac output

Question 39

use of a b2 selective agonist?

Answer 39

relaxation of bronchial smooth muscle