ANS Physiology

Question 1

What is the efferent path of the ANS?

Answer 1

A two-neuron link

Question 2

Which transmitters are present in the ANS?

Answer 2

ACh, adrenaline/nor

Question 3

Can you control the ANS?

Answer 3

No, it is involuntary.

Question 4

Where are the preganglionic fibers of the parasympathetic division located?

Answer 4

Cranial and sacral segments.

Question 5

Where are the preganglionic fibers of the sympathetic division located?

Answer 5

Thoracic and lumbar segments.

Question 6

How do the ganglion locations differ between SNS and ANS?

Answer 6

Ganglion in the ANS are close to the target.

Question 7

What is the lateral horn?

Answer 7

The origin of the pre-ganglionic fiber in the lateral ventral root.

Question 8

Divergence

Answer 8

Fibers split to different locations.

Question 9

Convergence

Answer 9

Fibers accumulate to one ganglion, one common destination.

Question 10

White ramus communicans

Answer 10

Myelinated branch between sensory nerve and ganglion.

Question 11

Gray ramus communicans

Answer 11

Non-myelinated branch between afferent nerve and target.

Question 12

Sympathetoc chain

Answer 12

Consists of chains of ganglions that divide into either another series of ganglia or a pathway towards a target.

Question 13

Collateral/Prevertebral ganglion

Answer 13

In front of vertebral column, does not terminate in chain-ganglion.

Question 14

Varicosities

Answer 14

Storage site for vesicles containing NT in smooth muscle cells

Question 15

Briefly describe the flow of transmission in the sympathy-adrenal system

Answer 15

Spinal cord, sympathetic ganglion, adrenal medulla.

Question 16

Chromaffin cells

Answer 16

similar to Sympathetic post-ganglion, release NT that travel via blood.

Question 17

What is release influenced by in the sympathy-adrenal system?

Answer 17

Pre-ganglionic fibers.

Question 18

Which NT is released from the somatic nerve?

Answer 18

Acetylcholine

Question 19

Which NT is released from the parasympathetic fiber?

Answer 19

Ganglion: Acetylcholine Target: Acetylcholine

Question 20

Which NT is released from the sympathetic fiber?

Answer 20

Ganglion: Acetylcholine, Target: Noradrenaline

Question 21

Specifically, which NT is released in the sympathoadrenal system?

Answer 21

Adrenal medulla: Acetylcholine, target: NA

Question 22

Briefly describe the production of Ach

Answer 22

Acetyl CoA, choline carrier + Acetyl CoA = acetylcholine

Question 23

Briefly describe NA synthesis

Answer 23

Tyrosine, DOPA, Dopamine, NA

Question 24

What are the two cholinergic receptors? What is the category of their target cells?

Answer 24

Nicotinic (Skeletic muscle and nervous tissue)

Muscarinic (Smooth muscle)

Question 25

What are the two adrenergic receptors? What do these receptors target?

Answer 25

Alpha and Beta, target smooth muscle (IN ANS)

Question 26

What do alpha receptors specifically target?

Answer 26

Eye, blood vessels, GIT, presynaptic endings

Question 27

What do beta receptors specifically target?

Answer 27

Heart, kidney, blood vessels, GIT

Question 28

Muscanaric and adrenergic receptors are ______ receptors

Answer 28

Metabotropic

Question 29

The nicotinic receptor is a _______ receptor

Answer 29

Ionotropic

Question 30

What do ionotropic receptors look like?

Answer 30

Doughnuts

Question 31

What do metabotropic receptors look like?

Answer 31

Snake

Question 32

What is the product of activating a metabotropic receptor?

Answer 32

Secondary messenger phosphorylates a protein, causing a cellular response.

Question 33

What are non-adrenaline/choline messengers?

Answer 33

Peptides Amines Amino acids Gases

Question 34

Most tissues have _______ innervation, what does this means? What usually occurs when these nerves are activated?

Answer 34

dual, this means that the two divisions of ANS typically produce opposite or similar/complimentary effects on the same tissue.

Question 35

What is the simplified function of the parasympathetic nervous system?

Answer 35

Rest and Digest

Question 36

What is an oversimplified function of the sympathetic nervous system?

Answer 36

Fight or flight.

Question 37

What happens in the eye (both SNS and PNS)

Answer 37

SNS: relaxes for far vision PNS: constricts for near vision

Question 38

What happens in the heart (SNS and PNS)

Answer 38

PNS: descreases heart rate SNS: increases heart rate

Question 39

What happens in the exocrine glands? (SNS and PNS)

Answer 39

PNS: lots of watery saliva SNS: thick saliva, increases temperature regulation

Question 40

What happens in blood vessels (SNS only)

Answer 40

Constriction

Question 41

What happens in the gut? (SNS and PNS)

Answer 41

PNS: increased motility SNS: Decreased motility

Question 42

What happens in the lungs? (SNS and PNS)

Answer 42

PNS: airway constriction SNS: airway dilation

Question 43

What happens in the urinary bladder? (PNS only)

Answer 43

Contraction

Question 44

What happens in the genitalia? (SNS and PNS)

Answer 44

PNS: increased erection SNS: Contracts smooth muscle (ejaculation)

Question 45

What are the major integrating centres for autonomic reflexes?

Answer 45

Hypothalamus, brainstem, spinal cord.

Question 46

Role of ANS in mictrurition reflex

Answer 46

Stretch receptors in bladder activate ANS and somatic nerve, relaxation of sphincter and contraction of bladder.

Question 47

Decreased resistance in blood vessels means:

Answer 47

dilated blood vessels

Question 48

What is BP equal to?

Answer 48

Resistance x heart rate x force

Question 49

Temperature regulation (Too cold)

Answer 49

``` Increased metabolism (symp.adrenaline) Inhibition of sweating (decreased symp to sweat glands) Vasoconstriction (increased symp to vessels) ```

Question 50

Temperature regulation (Too hot)

Answer 50

``` Decreased metabolism (decreased symp.adreno) Increased sweating (increased symp ACH) Vasodilation (decreased symp to blood vessels) ```

Question 51

Drugs that mimic the action of ACh

Answer 51

cholinomimetics

Question 52

Drugs that mimic NA

Answer 52

adrenomimetics

Question 53

Drugs that block action of ACh

Answer 53

anticholinergics

Question 54

Drugs that block action of NA

Answer 54

antiadrenergics