Lecture 24: The Autonomic Nervous System

Question 1

Homeostasis

Answer 1

Dynamic balance between the autonomic branches (sympathetic and parasympathetic)

Question 2

Sympathetic Nervous System

Answer 2

Fight or flight

Question 3

Parasympathetic Nervous System

Answer 3

Rest and digest

Question 4

Visceral Reflexes

Answer 4

Happens in spinal cord

Question 5

Viscera

Answer 5

Where autonomic, polysynaptic reflexes are initiated

Question 6

Automatic Motor Responses

Answer 6

Doesn’t go to brain, no cognition

Question 7

Higher Order

Answer 7

In brain stem, hypothalamus (mostly)

Question 8

What functions do higher order contain control centers and nuclei for?

Answer 8

Salivation + swallowing, digestive secretions, peristalsis, urinary retention

Question 9

What responses do the pons, hypothalamus and medulla initiate?

Answer 9

Autonomic, endocrine, and behavioral responses

Question 10

How are autonomic functions regulated?

Answer 10

Tonic v antagonistic control

Question 11

Most autonomic regulation is:

Answer 11

Antagonistic

except for sweat glands, smooth muscle dilation

Question 12

ANS general anatomy

Answer 12

Two neurons (preganglionic and postganglionic) that synapse in an autonomic ganglion

Question 13

Where do sympathetic pathways originate from?

Answer 13

Thoracic and L1-L2 region of spinal cord

Question 14

Where do parasympathetic pathways originate from?

Answer 14

Brain stem and sacral region of spinal cord

Question 15

Are sympathetic pathway ganglia closer to the spinal cord or target?

Answer 15

Spinal cord

Question 16

Are parasympathetic pathway ganglia closer to the spinal cord or target?

Answer 16

Target

Question 17

Length of sympathetic pathway neurons

Answer 17

Short pre-ganglionic neuron, long post-ganglionic neuron

Question 18

Length of parasympathetic pathway neurons

Answer 18

Long pre-ganglionic neuron, short post-ganglionic neuron

Question 19

What type of receptors do sympathetic pathways have?

Answer 19

Adrenergic receptors

Question 20

What does the post-ganglionic neuron of the sympathetic pathway secrete to the receptor on the target tissue?

Answer 20

Norepinephrine

Question 21

What type of receptors do parasympathetic pathways have?

Answer 21

Muscarinic

Question 22

What does the post-ganglionic neuron of the parasympathetic pathway secrete to the receptor on the target tissue?

Answer 22

ACh

Question 23

Dual Innervation of most organs

Answer 23

Balance between parasympathetic and sympathetic activity

Increase of activity in one couple to decrease in other

Question 24

Autonomic tone

Answer 24

Resting level of activity even without stimulation

Nerves can increase of decrease activity quickly

Question 25

Nicotinic Receptors

Answer 25

Ionotropic, ion channels Cation non-selective, produces EPSP

Question 26

Muscarinic Receptors

Answer 26

GPCR, series of second messengers that opens up K+ (IPSP) and Ca2+ channels (EPSP)

Question 27

Vagus Nerve

Answer 27

75% of all parasympathetic outflow Innervates structures in neck, thoracic and abdominopelvic cavities including distal portion of large intestine

Question 28

Sympathetic Chain

Answer 28

Adjacent to vertebral column

Question 29

Collateral Ganglia

Answer 29

Anterior of Vertebral bodies