PNS/SNS receptors and actions

Question 1

PNS: heart receptor and action

Answer 1

M2
decrease HR
decrease atrial contraction
decrease AV conduction

Question 2

SNS: heart receptor and action

Answer 2

B1
increase HR
increase contraction
increase AV conduction

Question 3

PNS: vessels

Answer 3

M
vasodilation (due to increased NO via M1/3 on endothelial cell–> cGMP–>relaxation)
There is no direct parasympathetic innervation.

Question 4

SNS vessels

Answer 4

a1 on all vessels: constrict–>increased BP

B2 on some vessels: vasodilation (increase perfusion)

Question 5

PNS: lungs

Answer 5

M
bronchoconstriction
increased secretions

Question 6

SNS: lungs

Answer 6

B2

bronchodilation

Question 7

PNS eye

Answer 7

M: contraction of iris sphincter muscle (pupil contracts: miosis)
M: contraction of ciliary muscle (lens accommodates for near vision)

Question 8

SNS eye

Answer 8

a1: contraction of iris radial muscle (pupil dilates: mydriasis)
B1, B2: increase aqueous humor production–>increase IOP

Question 9

PNS: GI

Answer 9

M: increase secretions
M: increase motility

Question 10

SNS: GI

Answer 10

a2: decrease muscle motility and tone, contract sphincters

B2,3 relax

Question 11

PNS: GU

Answer 11

M: contraction of detrusor
M: relax trigone and sphincter
Also: erection

Question 12

SNS: GU

Answer 12

a1: contract trigone/sphincter; ejaculation

B2,3: relax detrusor, relax uterine SM