Sec: 1 ANS Review

Question 1

Acetylcholine (ACH) is the neurotransmiter for which divisions of the ANS? Name the receptors for each corresponding division.

Answer 1

Somatic-Nicotinic.
PNS-Muscarinic
*SNS sweat glands - Muscarinic (the exception to the alpha and beta receptors of the SNS)

Question 2

PNS ratio of pre to post ganglionic fibers?

Answer 2

1:1 (discrete innervation)

Question 3

SNS ratio of pre to post ganglionic fibers?

Answer 3

1:20 (diffuse innervation)

Question 4

Which division is distributed to all tissues?

Answer 4

SNS

Question 5

Name the two anatomical sites of barorecptors and what they sense?

Answer 5

Aortic arch and carotid sinus baroreceptors sense mean arterial P (Sys-Dia).

Question 6

How does the SNS affect changes in BP? What receptor subtypes?

Answer 6

Increases contractility and HR (beta 1) and increase vasomotor tone (alpha-1)

Question 7

All autonomic ganglia (PNS and SNS) and the adrenal medulla host which receptor?

Answer 7

Cholinergic receptors- specifically, Nicotinic neuronal substype (Nn)

Question 8

Name all the receptors on vascular endothelium and vascular smooth muscle cells (be specific for a) muscle and b) skin and mucosa).

Answer 8

M3 (not innervated)
Skeletal A1, B2
Skin and mucosa A1

Question 9

CNS cholinergic receptor?

Answer 9

M-Muscarinic

Question 10

Adrenergic receptors can be stimulated by which 3 endogenous compounds? Explain their origin and classification.

Answer 10

NE-Neurotransmitter released from synaptic nerve terminals
E-Hormone released from Adrenal medulla
DA-CNS neurotransmitter.

Question 11

AP depolarizes presynaptic terminals opening ____. ______ influx causes synaptic vesicles to _____. NT is released into synaptic cleft by ______.

Answer 11

AP depolarizes presynaptic terminals opening neuronal Ca Channels. Calcium influx causes synaptic vesicles to fuse with the membrane. NT is released into synaptic cleft by exocytosis.

Question 12

Both nicotine and ACH stimulate which receptor at the ganglion? which receptor at the neuromuscular junction?

Answer 12

Nicotinic neuronal (Nn) 
Nicotinic muscular (Nm)

Question 13

What activates the nicotinic neuronal receptors? What is the effect?

Answer 13

Nicotine and ACH. Opens ligand gated ion channels, Na infuses cell and triggers an EPSP.

Question 14

What kind of drug is mecamylamine

Answer 14

antihypertensive

Question 15

Mechanism of action for mecamylamine

Answer 15

noncompetitive agonist of Nn receptors…blocks activation of postganglionic SNS and PNS nerve fibers.

Question 16

The parasympathic division maintains dominant control of most organ systems. Which 3 tissues experience dominant control from the SNS?

Answer 16

Arterioles, veins, and sweat glands.