Autonomic physiology

Question 1

Which branch of the nervous system is voluntary and how does it send its signal?

Answer 1

Somatic , and it is one axon orginating in the CNS and directly into the muscle

Question 2

How are the parasympathetic axons different from the sympathetic axons?

Answer 2

Parasympathetic axons have a long preganglionic axon and a short postganglionic axon, while the sympathetic axons have a short preganglionic and long postganglionic

Question 3

What does the parasympathetic ganglionic axons release?

Answer 3

The parasympathetic releases ACh at both the pre and post synaptic junctions

Question 4

What does the sympathetic ganglionic axons release?

Answer 4

They release ACh at the presynaptic junction and either ACh or NE/E at the post ganglionic junctions to either muscarinic or Alpha/beta anergic

Question 5

How is the actions of the parasympathetic nervous system terminated?

Answer 5

Acetylcholinesterase

Question 6

What are all autonomic receptors coupled to?

Answer 6

GTP binding proteins including Gq (PI turnover), Gs (increase cAMP), and Gi (decrease cAMP, increased K+ conductance)

Question 7

Where does the PNS originate from in the spinal cord?

Answer 7

Cranial/Sacral

Question 8

Where does the SNS originate from in the spinal cord?

Answer 8

Thoracic, upper lumbar

Question 9

How are actions terminated in the SNS?

Answer 9

Reuptake, degradative enzymes

Question 10

How is acteylecholine synethesized?

Answer 10

From choline and acetate via action of choline acetyletransferase

Question 11

What do ACE inhibitors target?

Answer 11

Acetyletransferase to stop the increase of ACh

Question 12

What is the process of norepinephrine synthesis?

Answer 12

Tyrosine –> DOPA –> Dopamine (stored)–>Norepinephrine

Question 13

How is NE action terminated?

Answer 13

Degradative enzymes MAO and Catechol-O-methytransferase

Question 14

How does the autonomic innervation affect the lungs?

Answer 14

SNS –> Dilation of the bronchioles

PNS–> Constrict bronchioles

Question 15

How does the autonomic innervation affect the heart?

Answer 15

SNS –> Beta-1 receptors stimuates the heart at SA node, increase AV nodal conduction, and force of contraction
PNS –> M2 receptors, decreases AV nodal conduction, no parasympathetic innervation of the ventricle, but exogenous ACh will decrease force of contraction

Question 16

How does the autonomic innervation affect the vasculature?

Answer 16

SNS –> Alpha-1 - vasoconstriction, Beta2 vasodilation *via EPI)
There is no ONS innervation of vasculature but exogenous muscarinic drugs will cause vasodilation (NO)

Question 17

How does the autonomic innervation affect the baroreceptors?

Answer 17

Reflex phenomena - decrease in BP sensed by baroreceptors will lead to an increase in heart rate and increase in BP will lead to decrease in HR

Question 18

How does the autonomic innervation affect the eyes?

Answer 18

SNS –> alpha 1, dilator

PNS–> M3 receptors, constrictor (light)

Question 19

How does the autonomic innervation affect the ciliary muscle?

Answer 19

SNS–> Beta2, causes relaxation for far view

PNS–> M3, contraction for near vision

Question 20

How does the autonomic innervation affect the liver?

Answer 20

SNS will lead to an increase in glucose

Question 21

What all entails the fight or flight response?

Answer 21

rlease of epi leads to coordinated response, epi causes vasoconstriction of visceral beds and vasodilation of the vessels in skeletal muscel, bronchiols to dilate, GI tract and bladder to relax, eyes to dilate, skin to sweat, glycogenolysis in the liver