15CHAPTER 15: AUTONOMIC NERVOUS SYSTEM Flashcards Preview

Anatomy and Physiology > 15CHAPTER 15: AUTONOMIC NERVOUS SYSTEM > Flashcards

Flashcards in 15CHAPTER 15: AUTONOMIC NERVOUS SYSTEM Deck (57):
1

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

S= fight or flight
P= Rest and digest

2

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

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

3

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

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

4

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

S= decreases blood flow
P= micturition reflex

5

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

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

6

Where is the sympathetic and parasympathetic ANS located?

S= thoracolumbar
P= craniosacral

7

Which ANS is responsible for maintaining homeostasis?

Both, sympathetic and parasympathetic ANS

8

Which ANS has background rate of activity causing autonomic tone?

Both, sympathetic and parasympathetic ANS

9

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

Preganglionic and postganglionic neurons

10

What are preganglionic neurons?

Cell body in spinal cord or brainstem

11

What are postganglionic neurons?

Cell body in autonomic ganglion or near the target

12

Where does the Sympathetic NS arise from?

the thoracolumbar location of the spinal cord.

13

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

in the lateral horn of gray matter in spinal cord

14

In the SNS, where does the axons travel?

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

15

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

1:17

16

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

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

17

What occurs in the spinal nerve route?

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.

18

What occurs in the sympathetic nerve route?

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

19

What occurs in the splanchnic nerve route?

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

20

Where can you find the adrenal glands?

Sits on top of kidneys

21

What does the adrenal cortex secrete?

Steroid hormones

22

What does the adrenal medulla contain?

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

23

The preganglionic neuron stimulates modified postganglionic neurons to release what?

Hormones into blood

24

Where does the parasympathetic NS arise from?

The craniosacral location

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?

Short postganglionic neurons in terminal ganglia near target organ

26

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

Near the target

27

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

1:2

28

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

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

29

What is the enteric nervous system specific to?

The digestive tract

30

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

Neither

31

What does the enteric nervous system regulate?

Regulated motility

32

What is the enteric nervous system regulated by?

ANS

33

What are the 2 types of fibres in the ANS?

Cholinergic fibers and adrenergic fibers

34

What does adrenergic fibers secrete?

Secrete (NE), excitatory/inhibitory

35

What do cholinergic fibers secrete?

Secrete (ACh), excitatory/inhibitory

36

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

Cholinergic receptors, Adrenergic Receptors (Sympathetic NS only)

37

What are the 2 types of Ach receptors?

Nicotinic and muscarinic receptors

38

What do nicotinic receptors do?

Opens ligand-gated ion channel

39

Where are nicotinic receptors located?

At neuromuscular junctions and on postganglionic neurons of ANS

40

What is the action of nicotinic receptors?

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

41

What is a muscarinic receptor?

G protein coupled receptors – second-messenger systems

42

Where are muscarinic receptors located?

Neuromuscular junctions and on postganglionic neurons of ANS

43

What is the action of muscarinic receptors?

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

44

What are the 2 classes of Adrenergic Receptors?

Alpha (α and Beta (β

45

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

Alpha= usually excitatory
Beta= usually inhibitory

46

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

Decreases strength of heart contraction and decreases HR

47

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

Vasoconstriction of heart vessels = decrease in blood flow

48

What is propranolol and why is it prescribed?

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

49

What is dual innervation?

One target receives both sympathetic and parasympathetic input

50

What can dual innervation can be?

Antagonistic (pupil diameter)
Cooperative (salivation)

51

What is it called when blood vessels increase firing?

Vasoconstriction

52

What is it called when blood vessels decrease firing?

Vasodilatation

53

What does the limbic system provide?

pathway connecting mental experience with ANS

54

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

the brain and ANS

55

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

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

56

What does the hypothalamus coordinate?

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

57

What autonomic reflexes does the spinal cord integrate?

micturition and defecation