14-1: Overview

Question 1

The Autonomic Nervous System is the branch of the ___Nervous System that conveys information from the ____ to ____.

Answer 1

Efferent; CNS; cardiac and smooth muscles or gland

Question 2

The Peripheral Nervous System has 2 branches: ___.

Answer 2

afferent and efferent

Question 3

The Efferent Nervous System has 2 branches: ___.

Answer 3

autonomic and somatic

Question 4

What are 5 ways that the ANS differs from the SNS?

Answer 4

effectors: skeletal muscle | smooth muscle, cardiac muscle, and glands

type of control: voluntary | involuntary

pathway: ONE motor neuron btwn CNS and effector | TWO motor neurons btwn CNS and effector

action on effector: always excitatory | excitatory or inhibitory

neurotransmitter: acetylcholine | acetylcholine or norepinephrine

Question 5

What are some examples of autonomic activity?

Answer 5

size of pupil
dilation of blood vessels
heart rate
movement of digestive tract
secretion of saliva
emptying of bladder

Question 6

Autonomic pathways almost always consist of 2 ____ neurons: ___ and ___, which synapse at ___.

Answer 6

motor; preganglionic neuron; postganglionic neuron; autonomic ganglion

Question 7

preganglionic neuron

Answer 7

cell body in the brain or spinal cord, and its myelinated axon passes out of the CNS as part of a cranial or spinal nerve

Question 8

postganglionic neuron

Answer 8

lies entirely outside of the CNS. Cell body is in an autonomic ganglion and unmyelinated axon leaves the ganglion and synapses with a visceral effector

Question 9

autonomic ganglion

Answer 9

where pre and postganglionic neurons synapse

Question 10

The autonomic ganglion has the ____ of ____; the dorsal root ganglia has ___ of ___.

Answer 10

cell bodies; motor neurons and synapses; cell bodies; sensory neurons

Question 11

parasympathetic division

Answer 11

concerned with activities that conserve and restore energy during times of rest (food digestion and absorbtion into body) - normally in control

Question 12

sympathetic division

Answer 12

involves spending energy when the body is under physicial or emotional stress (eg. exercise, rage, fear)

Question 13

In the fight or flight response:

1. pupils ___
2. heart rate and blood pressure ____
3. blood vessels to skin and viscera ____
4. vessels to skeletal and cardiac muscle ____
5. breathing becomes ___; airways ____
6. blood sugar level ____

Answer 13

1. pupils dilate
2. heart rate and blood pressure increase
3. blood vessels to skin and viscera constrict
4. vessels to skeletal and cardiac muscle dilate
5. breathing becomes rapid and deep - airways dilate
6. blood sugar level increases

Question 14

Dual innervation

Answer 14

most organs get nerve fibers from both sympathetic and parasympathetic division. The two cause opposite effects - if one stimulates an organ, the other inhibits it

Question 15

heart rate: SANS ____, PANS ___

intenstinal motility: SANS ____, PANS ____

Answer 15

heart rate: SANS increase and PANS decreases

intestinal motility: SANS decreases and PANS increases

Question 16

Sympathetic neurons originate in the ______; parasympathetic neurons origin in the ______.

Answer 16

thoracic and lumbar regions of spinal cord; brainstem and sacral region of the cord

Question 17

Sympathetic has ___ preganglionic fibers and ___ postganglionic fibers; parasympathetic has ___ preganglionic and ___ postganglionic

Answer 17

SANS: short pre; long post
PANS: long pre; short post

Question 18

Sympathetic ganglia lie ___ to the spinal cord and parasympathetic are ___ to the cord.

Answer 18

close; far

Question 19

PANS preganglionic neurons

Answer 19

have cell bodies located in the nuclei of cranial nerves III, VII, IX, and X (in the brainstem) and in the laterla horns of spinal segments S2 to S4

Question 20

How many nerves are controled by the PANS?

Answer 20

7 total - 4 cranial (III, VII, IX and X) and 3 sacral

Question 21

The autonomic ganglia in the PANS is a ____ and in the SANS is a ____.

Answer 21

terminal ganglion; paravertebral chain ganglion

Question 22

SANS preganglionic neurons

Answer 22

have cell bodies in the lateral horns of spinal cord segments T1 to L2

Question 23

How many nerves are controled by the SANS?

Answer 23

14 spinal nerves

Question 24

paravertebral chain ganglion

Answer 24

series of 23 ganglia in a vertical row on each side of the vertebral column; they form the “sympathetic trunk”

Question 25

When a preganglionic axon reaches a paravertebral ganglion:

1. It can synapse with a post ganglionic neuron in the ____ paravertebral ganglion
2. It can go ____ the chain and synapose with a postganglionic neuron in a ___ paravertebral ganglion
3. It can pass through the ganglion and synapse with a postganglionic neuron in a ____, located ___ to the vertebral column

Answer 25

1. same
2. up and down; different
3. prevertebral ganglion; anterior

Question 26

neurotransmitter

Answer 26

these chemicals are released at the synapses between neurons and the neuromuscular or neuroglandular junctions

Question 27

What are the two types of autonomic nerve fibers?

Answer 27

cholinergic (secretes acetylcholine) and adrenergic (norepinephrine)

Question 28

Where are the cholinergic fibers?

Answer 28

all somatic motor neurons
all preganglionic axons
all parasympathetic postganglionic axons

(and a few sympathetic postganglionic axons to sweat glands and some blood vessels)

Question 29

Where are the adrenergic fibers?

Answer 29

most sympathetic postganglionic axons

Question 30

Effects of cholinergic fibers are ___.

Answer 30

short lived and local (since ACh is quickly inactivated by acetylcholinesterase)

Question 31

Effects of adrenergic fibers are ___.

Answer 31

long lasting and more widespread (since norepinephrine enter the blood and is slowly inactivated)

Question 32

Receptors are found ____.

Answer 32

on viscera and the cell bodies of postganglionic neurons

Question 33

What are the types of cholinergic and adrenergic receptors?

Answer 33

cholinergic: nicotinic and muscarinic
adrenergic: alpha and beta

Question 34

nicotinic receptor

Answer 34

found on cell bodies of all post ganglionic neurons and skeletal muscles

Effect is always stimulation

Question 35

muscarinic receptors

Answer 35

occur on all effector cells stimulated by postganglionic, chonlinergic fibers (all parasympathetic)

effect is either excitatory or inhibitory (usually excitatory, but slows down heart rate)

Question 36

alpha receptor

Answer 36

When NE binds to these, the organ is usually stimulated

Question 37

beta receptor

Answer 37

when NE binds to these, the organ is usually inhibited

Question 38

What is an exception to the alpha-beta receptor rule?

Answer 38

The beta1 receptors of the heart are excitatory