Autonomic Nervous System (Ch 18)

Question 1

ANS and functions

Answer 1

• -> general visceral motor system of PNS
• involuntary control of visceral functions, regulates smooth muscles, cardiac muscles, and glands
• regulates heart rate, breathing, body temp, and other functions vital to maintaining homeostasis
• controls all “routine” functions of physiological systems

Question 2

Somatic vs. Autonomic

Answer 2

Somatic:
-ONE neuron in pathway
-from skin/special senses to skeletal muscle
Autonomic: 
-TWO neurons in pathway
-from viscera to smooth/cardiac muscle

Question 3

Sympathetic and Parasympathetic

Answer 3

• most organs/glands receive input from both regions
• sympathetic = activation
• parasympathetic = inhibition

Question 4

Sympathetic

Answer 4

“Thoracolumbar”

• for emergencies, exercise, excitement
• -> dilate pupils, inhibit bladder contractions

Question 5

Parasympathetic

Answer 5

“Craniosacral”

• normal everyday functioning
• -> “housekeeping,” slow HR, relaxation, urination, digest food

Question 6

Sympathetic Trunk

Answer 6

a. k.a. Paravertebral Ganglia
- along both sides of vertebral column from neck to pelvis
- connect to ventral rami by rami communicans (white rami are lateral to grey rami, approx 1 per spinal nerve)
- different pathway for autonomic nerves to reach their target (ex. the heart)

Question 7

Spinal Nerves: Roots

Answer 7

emerge from spinal cord = ventral/dorsal roots –> form spinal nerves

Question 8

Ventral Roots

Answer 8

contain only motor axons (carry motor info)

-motor neuron cell bodies are in ventral horn

Question 9

Dorsal Roots

Answer 9

contain sensory axons only (carry sensory info)

-sensory axon cell bodies are in dorsal root ganglion

Question 10

Spinal Nerves: Rami

Answer 10

spinal nerves travel through intervertebral foramen
–>after that they split into ventral/dorsal rami (carry sensory + motor neurons)

1. Ventral Rami: form plexuses
2. Dorsal Rami: innervate small strip of back