Autonomic System

Question 1

What is the purpose of the autonomic system?

Answer 1

Controls function of visceral system (smooth and cardiac muscles, and other glands)

Question 2

What are the three parts of the autonomic system?

Answer 2

Parasympathetic, Sympathetic, and Enteric

Question 3

Autonomic system does not have conscious control; however, what can it modulate?

Answer 3

Conscious drive

Question 4

Where are the autonomic system fibers found?

Answer 4

Lateral horn

Question 5

Where are fibers from the sympathetic system travel to and found?

Answer 5

Thoracolumbar Column (T1-L3) and found in the lateral horn

Question 6

Where are fibers from parasympathetic system traveling to and found?

Answer 6

Start at brainstem (CN 3,7,9,10) and S2-S4

Question 7

How are the somatic system and autonomic systems alike?

Answer 7

Their connection to reflex activity is the similar and their connection to higher function CNS are similar

Question 8

How do the somatic and autonomic systems differ?

Answer 8

Structures that receive afferent information (thalamus - somatic) and (hypothalamus - autonomic). Descending pathways leave from (cerebral cortex - somatic) and (hypothalamus - autonomic).
Somatic systems only have ONE neuron pathway to innervate skeletal muscle; whereas, autonomic system has TWO neuron pathways to innervate target smooth muscles, cardiac muscles, and glands. Somatic muscle snaypse by way of chemical synapse; whereas, autonomic system synapses with electrical synapse

Question 9

Explain the two neuron pathway for autonomic system?

Answer 9

Pregangolic fibers exit through the ventral root and synapse with gangiolic fibers in the postsynaptic neuron then innervate smooth and cardiac muscles, and glands

Question 10

How do preganglionic fibers differ from postganglionic fibers?

Answer 10

Preganglionic are lightly myelinated

Postganglionic are not myelinated

Question 11

How does the parasympathetic and sympathetic pathway differ in regards to the postganglionic and preganglionic fibers?

Answer 11

Parasympathetic have longer preganglionic fibers and their ganglion bodies are closer to target cells
Sympathetic have shorter preganglionic fibers and their ganglion bodies are closer to the spinal cord

Question 12

What does the sympathetic system control?

Answer 12

Functions in response to emotional or physical stress

Question 13

What are the 4 E’s that relate to the sympathetic system?

Answer 13

Exercise, Embarrassment, Excitement, Emergency

Question 14

What is the function of the sympathetic nervous system?

Answer 14

Pupil dilation, Bronchodilation, Vasocontriction (reroutes blood to the muscles), Inhibition of lacriminal and salivation glands, stimulates sweat glands, stimulates piloerection, inhibits digestive system, and stimulates hormones (adrenal medulla: releases NE and Epinephrine; Pancreas: Glucagon)

Question 15

Where does the sympathetic system start?

Answer 15

Lateral Column of Spinal Cord

Question 16

Where do the preganglionic neurons of the sympathetic system extend?

Answer 16

T1-L3 (upper thoracolumbar region: head and thorax; lower lumbar regions: pelvic organs, abdominal organs, and LE targets)

Question 17

Explain the three different routes in which efferent information take exiting the spinal cord through the ventral rami?

Answer 17

1. Travel through the white communicating rami of the sympathetic trunk and synapse immediately to postganglionic neurons
2. Travel through the white communicating rami of the sympathetic trunk and then synapse according on where it ascends and descends
3. Travels through the white communicating rami of the sympathetic trunk without synapsing and then goes to synapse to the prevertebral ganglions

Question 18

Explain where the three targets of the sympathetic nervous system exit to

Answer 18

1. Preganglionic fibers that synapse directly in the sympathetic trunk exit directly to the targets of the LE
2. Preganglionic fibers that synapse whether there are descending or ascending exit to blood vessels via the gray communicating matter
3. Preganglionic fibers that travel through the sympathetic trunk without synapsing and then synapse at the prevertebral ganglion exit to the heart, lungs, gut, liver, kidney, bladder, and reproductive organs

Question 19

What is the function of the parasympathetic system?

Answer 19

The function of the parasympathetic system is energy storage and conversation of energy

Question 20

What are components of the parasympathetic?

Answer 20

Rest digest,
Contraction of bladder, constriction of pupils, vasodilation, bronchoconstriction, decrease of HR, Preganglionic nuclei of sacral nerve (s2-s4)

Question 21

What are the four nuclei that are associated with efferent structures of the parasympathetic system?

Answer 21

EW Nuclei, Inferior and Superior Salivary Nuclei, Nucleus Ambigous, Dorsal Motor Nuclei of Vagus nerve

Question 22

Where do the efferent structures of the parasympathetic exit to?

Answer 22

1. EW nucleus –> cilliary muscles for pupil constriction
2. Inferior and Superior Salivary Nuclei —> lacriminal and salivary glands
3. Nucleus Ambigous –> Decreasing HR
4. Dorsal Motor Nucleus of Vagus N. —> glandular secretion of abdominal, slow heart rate, broncho constriction of lungs, and increase gut motility

Preganglionic neurons from Sacral –> bladder contraction, vasodilation of rectum and colon, vasodilation of clitoral and penile

Question 23

Parasympathetic and Sympathetic structures are usually innervate the same structures. What does the sympathetic system ONLY innervate

Answer 23

S: Sweat glands
A: Adrenal Medulla
M: more blood vessels
E: Erector pili muscles

Question 24

What are some major differences between the parasympathetic and sympathetic system??

Answer 24

Sympathetic response are usually longer than parasympathetic due to: divergence of preganglionic neurons, unmyelinated post ganglionic neurons, presence of NE and epinephrine in the blood stream, slower inactivation of NE at the synapse