Autonomic Nervous System

Question 1

The autonomic nervous system is the subdivision of the peripheral nervous system that regulates body activities that are generally not under _____ control

Answer 1

conscious

Question 2

Where do the cell bodies of the somatic nervous system reside?

Answer 2

in the CNS (brain or spinal cord)

Question 3

Axons of the somatic nervous system extend where and are called what?

Answer 3

They extend all the way to their skeletal muscles as spinal nerves

Question 4

The autonomic nervous system consist of how many motor neurons? What are they called?

Answer 4

Chains of 2 motor neurons

 - first is the preganglionic neuron located in the brain or spinal cord and synapses with the 2nd neuron
 - second is the postganglionic neuron located in the ganglia outside the CNS and synapse with the organ it serves

Question 5

Is the pre- or postganglionic neuron slower? Why?

Answer 5

Postganglionic neuron is slower because it is lightly or unmyelinated

Question 6

What are the 2 divisions of the autonomic nervous system?

Answer 6

• Parasympathetic division

- Sympathetic division

Question 7

Although the parasympathetic and sympathetic divisions innervate most of the same organs they cause _____ effects

Answer 7

antagonistic

Question 8

The parasympathetic division is known as what?

Answer 8

The “rest & digest” system

Question 9

The sympathetic division is known as what?

Answer 9

The “fight or flight” system

Question 10

The parasympathetic division is aka what and why?

Answer 10

The craniosacral system because all its preganglionic neurons are in the brain stem or sacral levels of the spinal cord

Question 11

The preganglionic neurons of the parasympathetic division include cranial nerves __, __, __, and __ as well as the lateral horn of gray matter from S_- S_

Answer 11

CN III,VII, IX and X

S2-S4

Question 12

What does the parasympathetic division innervate?

Answer 12

internal organs (not skin)

Question 13

What neurotransmitter is released in all pre- and postganglionic parasympathetic neurons?

Answer 13

Acetylcholine

Question 14

Describe CN III (oculomotor) and its role in the PNS

Answer 14

It constricts the pupils

Question 15

Describe CN VII (facial) and its role in the PNS

Answer 15

It decreases the production of tears, nasal mucus, and saliva

Question 16

Describe CN IX (glossopharyngeal) and its role in the PNS

Answer 16

It effects the parotid gland which is a major salivary gland

Question 17

Describe CN X (vagus) and its role in the PNS

Answer 17

It innervates the visceral organs of the thorax & abdomen:

 - stimulates digestive glands
 - increases motility of smooth muscle of GI tract
 - decreases heart rate
 - causes bronchial constriction

Question 18

The sacral outflow from the parasympathetic nervous system from what nerves?

Answer 18

pelvic splanchnic nerves (S2-S4)

Question 19

The pelvic splanchnic nerves supply what 2 things?

Answer 19

• the 2nd half of large intestine

- all the pelvic (genitourinary) organs

Question 20

The sympathetic division is aka what and why?

Answer 20

The thoracolumbar system because all of its neurons are located in the lateral horn of gray matter from T1-L2

Question 21

Unlike the parasympathetic division, neurons of the sympathetic division go where?

Answer 21

everywhere in the body

Question 22

7 things associated with the SNS

Answer 22

• nervous sweat
• BP rises during excitement
• dry mouth
• dilated pupils
• increased HR
• increased respiratory rate
• liver release more glucose

Question 23

What neurotransmitter is released by most postganglionic sympathetic neurons?

Answer 23

Norepinephrine

Question 24

What neurotransmitter is released by most preganglionic sympathetic neurons?

Answer 24

acetylcholine

Question 25

Preganglionic axons of the sympathetic nervous system exit the spinal cord where? Where do they enter after they exit the spinal cord?

Answer 25

They exit the spinal cord through the ventral root and enter a spinal nerve

Question 26

Preganglionic axons of the sympathetic nervous system exit spinal nerves via what?

Answer 26

communicating ramus

Question 27

As soon as the preganglionic neurons enter the sympathetic trunk/chain what 3 things can they do?

Answer 27

1) Synapse on the postganglionic neuron in chain ganglion then return to spinal nerve and follow its branch to the skin
2) Ascend or descend within the sympathetic trunk, synapse with a postganglionic neuron within a chain ganglion, and then return to a spinal nerve at that level and follow branches to skin
3) Enter the sympathetic chain, pass through without synapsing with a postganglionic neuron, forming a splanchnic nerve that passes towards thoracic or abdominal organs

Question 28

Where do splanchnic nerves synapse?

Answer 28

In prevertebral ganglion in front of aorta

Question 29

Once synapsed, where do the postganglionic axons go?

Answer 29

They follow arteries to the organs