physiology of the ANS

Question 1

motor vs ANS cell bodies

Answer 1

motor - all cell bodies in CNS

ANS - TWO cell bodies - pre and post

Question 2

how does a synapse work

Answer 2

presynaptic terminal releases vesicles with neuronstransmitters

post synaptic cell has receptors for NT to bind to

Question 3

types of receptors

Answer 3

inotropic

metabotropic

Question 4

ionotropic receptors

Answer 4

channel that NT binds - receptor opens to allow ions to go in/out

Question 5

metabotropic (3) receptors

Answer 5

biochemical effect inside cell

1. Gq- inc IP3/DAG - inc Ca2+ released from stores
2. Gs- inc adenylyl cyclase - inc cAMP - change phosphorylation in cell
3. Gi- dec adenylyl cyclase - dec cAMP

Question 6

synapse between pre and post ganglionic neurons (SNS vs PSNS)

Answer 6

same between both SNS and PSNS

NT: acetylcholine

receptor: nicotinic cholinergic channel (on dendrites of post ganglionic cells)
result: allows Na+ to enter cell – depolarizes cell (more excitable)- produces action potential

Question 7

synapse between post ganglionic neurons and target tissue - PSNS

Answer 7

NT: Ach

receptor: muscarinic cholinergic receptor (connected G protein)

Question 8

M1R, M3R, M5R

Answer 8

bind Gq protein

PSNS receptor for post ganglionic neuron and target tissue

Question 9

M1R

Answer 9

PSNS

salivary glands, parietal cells of stomach
increases secretion

Question 10

M3R

Answer 10

PSNS

increase contraction: smooth muscle GI, detrusor wall bladder, ciliary muscle lens

increase secretion: pancreatic secretion

decrease contraction in atria

Question 11

M2R, M4R

Answer 11

bind Gi protein receptor

PSNS receptor for post ganglionic neuron and target tissue

Question 12

M2R

Answer 12

SNS

causes efflux of K+–> hyperpolarizes cells –>decreases conduction –> decreases heart rate

dec conduction velocity AV node

inc contraction smooth muscle spinsters GI tract (?)\
dec contraction spinchters in bladder (?)

Question 13

synapse between post ganglionic neurons and target tissue - SNS

Answer 13

NT: norepinephrine
receptor: adrenergic receptor (alpha, or beta)

Question 14

alpha 1 receptor

Answer 14

SNS

binds Gq - inc Ca2+

contraction: vascular smooth muscle, GIGU smooth muscle, radial muscle of eye (dilates pupil)

liver: glycogenlysis, gluconeogenesis
adipose tissue: lipolysis
lacrimal: decreased tear secretion

Question 15

alpha 2 receptor

Answer 15

SNS

binds Gi - dec cAMP

GIGU- sphincters contract
Vascular smooth muscle- relaxes
pancreases - inc glucagon, dec insulin
platelets- more clotting

Question 16

Beta 1 receptor

Answer 16

SNS

binds Gs - inc cAMP

inc. HR
inc ventricle contractility
salivary - reduced secretion
adipose - lipolysis

Question 17

Beta 2 receptor

Answer 17

SNS

binds Gs - inc cAMP

relaxation: bronchiole smooth muscle, GI hollow organs, vascular smooth muscle, ciliary muscle, GU muscles

liver - glycogenlysis

Question 18

how does the ciliary muscle work

Answer 18

contracts- makes lens rounder - see near better

relaxes- makes lens flatter - see far better

Question 19

Beta 3 receptor

Answer 19

binds Gs

white adipose tissue - lipolysis
brown adipose tissue - heat production

Question 20

adrenal medulla’s role

Answer 20

adds epinephrine to sympathetic response

Question 21

chromafin cells

Answer 21

in the adrenal medulla

can synthesize catelcholamines that release epinephrine

Question 22

presynaptic fibers and the adrenal medulla

Answer 22

special set of cells - do not go synapse sympathetic chain

instead go to the adrenal medulla and synapse ON chromafin cells

Question 23

what kind of receptors to chromafin cells have

Answer 23

nicotinic cholinergic receptors

open when Ach is released (bc presynaptic cell synapses)

channel opens –> sodium flows in –> chromafin cells depolarize and release epinephrine