15CHAPTER 15: AUTONOMIC NERVOUS SYSTEM

Question 1

What is the general function of the sympathetic and parasympathetic ANS?

Answer 1

S= fight or flight

P= Rest and digest

Question 2

Whats the difference in heart activity between the sympathetic and parasympathetic ANS?

Answer 2

S= increases HR, increases strength of contraction
P= decrease HR, and strength of contraction

Question 3

What is the difference in the digestive system between the sympathetic and parasympathetic ANS?

Answer 3

S= decreases blood flow,
P= increases motility and secretion

Question 4

What is the difference in the urinary system between the sympathetic and parasympathetic ANS?

Answer 4

S= decreases blood flow
P= micturition reflex

Question 5

What are the actions of blood vessels in the sympathetic and parasympathetic ANS?

Answer 5

S= stimulation = vasoconstriction = decrease in blood flow
P= none

Question 6

Where is the sympathetic and parasympathetic ANS located?

Answer 6

S= thoracolumbar
P= craniosacral

Question 7

Which ANS is responsible for maintaining homeostasis?

Answer 7

Both, sympathetic and parasympathetic ANS

Question 8

Which ANS has background rate of activity causing autonomic tone?

Answer 8

Both, sympathetic and parasympathetic ANS

Question 9

Neural pathways have what 2 neurons that come from the spinal cord and arrive at the target?

Answer 9

Preganglionic and postganglionic neurons

Question 10

What are preganglionic neurons?

Answer 10

Cell body in spinal cord or brainstem

Question 11

What are postganglionic neurons?

Answer 11

Cell body in autonomic ganglion or near the target

Question 12

Where does the Sympathetic NS arise from?

Answer 12

the thoracolumbar location of the spinal cord.

Question 13

In the SNS, short preganglionic myelinated neurons are with cell bodies located where?

Answer 13

in the lateral horn of gray matter in spinal cord

Question 14

In the SNS, where does the axons travel?

Answer 14

Axon travels in spinal nerve and then communicating ramus (white) to the sympathetic chain ganglion

Question 15

What is the ratio of preganglionic and postganglionic neurons in the SNS?

Answer 15

1:17

Question 16

From the sympathetic chain ganglion, what are the 3 pathways are possible for the ganglionic/postganglionic fibers?

Answer 16

1. Spinal nerve route
2. Sympathetic nerve route
3. Splanchnic nerve route

Question 17

What occurs in the spinal nerve route?

Answer 17

Preganglionic fibers synapse on postganglionic neurons in sympathetic chain ganglia = postganglionic fibers go back into spinal nerve via gray communicating ramus = take signal to skin, blood vessels, sweat glands etc.

Question 18

What occurs in the sympathetic nerve route?

Answer 18

Preganglionic fibers travel up (or down) the sympathetic trunk, synapse on postganglionic neurons in ganglia at other levels = postganglionic fibers take signal to heart, lungs, pupils, glands

Question 19

What occurs in the splanchnic nerve route?

Answer 19

Preganglionic fibers go through the chain without synapsing and continue as splanchnic nerves to synapse with postganglionic neurons in collateral ganglia (2nd set of ganglia) = postganglionic fibers take signal to digestive, reproductive, urinary organs

Question 20

Where can you find the adrenal glands?

Answer 20

Sits on top of kidneys

Question 21

What does the adrenal cortex secrete?

Answer 21

Steroid hormones

Question 22

What does the adrenal medulla contain?

Answer 22

Contains modified sympathetic ganglion (postganglionic neurons without dendrites or axons)

Question 23

The preganglionic neuron stimulates modified postganglionic neurons to release what?

Answer 23

Hormones into blood

Question 24

Where does the parasympathetic NS arise from?

Answer 24

The craniosacral location

Question 25

In the PNS, long preganglionic neurons, with cell bodies in brainstem (midbrain, pons, and medulla) or sacral spinal cord (S2 – S4) synapse with what and where?

Answer 25

Short postganglionic neurons in terminal ganglia near target organ

Question 26

In the PNS there are short postganglionic neurons with cell bodies located where?

Answer 26

Near the target

Question 27

What is the ratio of preganglionic and postganglion neurons in the PNS?

Answer 27

1:2

Question 28

What are the 4 cranial nerves that are controlled by the PNS?

Answer 28

Oculomotor (III), facial (VII), Glossopharyngeal (IX), vagus (X)

Question 29

What is the enteric nervous system specific to?

Answer 29

The digestive tract

Question 30

Does the enteric nervous system arise from the brain or spinal cord?

Answer 30

Neither

Question 31

What does the enteric nervous system regulate?

Answer 31

Regulated motility

Question 32

What is the enteric nervous system regulated by?

Answer 32

ANS

Question 33

What are the 2 types of fibres in the ANS?

Answer 33

Cholinergic fibers and adrenergic fibers

Question 34

What does adrenergic fibers secrete?

Answer 34

Secrete (NE), excitatory/inhibitory

Question 35

What do cholinergic fibers secrete?

Answer 35

Secrete (ACh), excitatory/inhibitory

Question 36

What are the types of receptor found in sympathetic and parasympathetic divisions?

Answer 36

Cholinergic receptors, Adrenergic Receptors (Sympathetic NS only)

Question 37

What are the 2 types of Ach receptors?

Answer 37

Nicotinic and muscarinic receptors

Question 38

What do nicotinic receptors do?

Answer 38

Opens ligand-gated ion channel

Question 39

Where are nicotinic receptors located?

Answer 39

At neuromuscular junctions and on postganglionic neurons of ANS

Question 40

What is the action of nicotinic receptors?

Answer 40

``` Excitatory Curare (poison) blocks nicotinic receptors = flaccid paralysis (decreases thoracic muscle contraction = suffocation) ```

Question 41

What is a muscarinic receptor?

Answer 41

G protein coupled receptors – second-messenger systems

Question 42

Where are muscarinic receptors located?

Answer 42

Neuromuscular junctions and on postganglionic neurons of ANS

Question 43

What is the action of muscarinic receptors?

Answer 43

``` Excitatory Curare (poison) blocks nicotinic receptors = flaccid paralysis (decreases thoracic muscle contraction = suffocation) ```

Question 44

What are the 2 classes of Adrenergic Receptors?

Answer 44

Alpha (α and Beta (β

Question 45

What action does alpha and beta classes of the adrenergic receptors do?

Answer 45

``` Alpha= usually excitatory Beta= usually inhibitory ```

Question 46

What happens when B1 (beta 1) receptors are blocked?

Answer 46

Decreases strength of heart contraction and decreases HR

Question 47

What happens when B2 (beta 2) receptors are blocked?

Answer 47

Vasoconstriction of heart vessels = decrease in blood flow

Question 48

What is propranolol and why is it prescribed?

Answer 48

A beta-blocker, prescribed to reduce hypertension (high BP)

Question 49

What is dual innervation?

Answer 49

One target receives both sympathetic and parasympathetic input

Question 50

What can dual innervation can be?

Answer 50

Antagonistic (pupil diameter) | Cooperative (salivation)

Question 51

What is it called when blood vessels increase firing?

Answer 51

Vasoconstriction

Question 52

What is it called when blood vessels decrease firing?

Answer 52

Vasodilatation

Question 53

What does the limbic system provide?

Answer 53

pathway connecting mental experience with ANS

Question 54

Hypothalamus (major control of ANS) acts as a bridge between what?

Answer 54

the brain and ANS

Question 55

The Midbrain, Pons, and Medulla have nuclei for what cranial nerves in what division?

Answer 55

Cranial nerves III, VII, IX, X of the parasympathetic division

Question 56

What does the hypothalamus coordinate?

Answer 56

Coordinates many ANS activities-BP, HR, vasomotion, GI tract motility and secretion

Question 57

What autonomic reflexes does the spinal cord integrate?

Answer 57

micturition and defecation