Autonomics: Lecture 5

Question 0

Autonomic Nervous System

Answer 0

Involuntary or unconscious control of two neuron pathway
Yes ganglia
Sensory input from general and visceral/Motor output to cardiac, smooth muscles, & glands
Excited with Ach & norepinephrine
Thin, sometimes myelinated axons

Question 1

Somatic Nervous System

Answer 1

Voluntary or subconscious control of single neuron pathway
No ganglia
Sensory input/Motor output to skeletal muscles
Excites with Ach only
Thick, myelinated axons

Question 2

Is White mater/rami or gray mater/rami myelinated?

Answer 2

White mater/rami

Question 3

How does the cardiac plexus function?

Answer 3

Sympathetically- Increases HR and BP

Parasympathetically- Decreases HR

Question 4

How does the pulmonary plexus function?

Answer 4

Sympathetically- Bronchodilation

Parasympathetically- Bronchoconstriction & increased secretion from mucous glands of bronchial tree

Question 5

How does the Esophageal plexus function?

Answer 5

Parasympathetically- Controls swallowing reflex

Question 6

How does the abdominal aortic plexus function?

Answer 6

Autonomic control of digestion

*Consists of celiac, superior mesenteric, and inferior mesenteric plexuses

Question 7

How does the hypogastric plexus function?

Answer 7

Autonomic control of urinary and reproductive function

Question 8

Describe the characteristics of the neural pathways of Parasympathetic neurons

Answer 8

Long preganglionic axon, Ach release only, short postganglionic axon
*No branching

Question 9

Describe the characteristics of the neural pathways of Sympathetic neurons

Answer 9

Short preganglionic axon with branching, Ach & Norepinephrine release, long postganglionic axon with branching

Question 10

What are the 4 areas of the CNS autonomic control area and what does each control?

Answer 10

Cerebrum- Conscious activities affect hypothalamus ANS control
Hypothalamus- Integration & command center for ANS (visceral) functions (emotions)
Brainstem- Contains major ANS reflex center
Spinal Cord- Contains ANS reflex centers for defecation & urination

Question 11

What region of the spinal cord are the Sympathetic Preganglionic neuron cell bodies housed?

Answer 11

Lateral horn of T1-L2

Question 12

Why does the sympathetic trunk look like a string of beads?

Answer 12

The “string” is composed of bundles of axons

The “beads” are the sympathetic trunk ganglion

Question 13

What do white rami do and where are they located?

Answer 13

Carry preganglionic sympathetic axons from T1-L2 spinal nerves to the sympathetic trunk
Myelinated

Question 14

What do gray rami do and where are they located?

Answer 14

Carry postganglionic sympathetic axons from the sympathetic trunk to the spinal nerve
Unmyelinated
Connect all spinal nerves to disperse sympathetic information to all parts of the body

Question 15

What are the characteristics of the Splanchnic nerve?

Answer 15

Composed of preganglionic sympathetic axons
Run anteriorly to sympathetic trunk to most abdominal viscera
Terminate in prevertebral ganglia
Sympathetic postganglionic axons extend from these ganglia and innervate many abdominal organs

Question 16

What are the routes a sympathetic signal can take?

Answer 16

Spinal nerve->White rami->A, B, C, or D
A) Ascend then synapse
B) Synapse at level of entry
C) Descend then synapse
D) Pass through without synapsing into abdominopelvic splanchnic nerve for innervation of abdominopelvic viscera only

Question 17

The parasympathetic division is also termed the _____?

Answer 17

Craniosacral division

Question 18

What are the cranial nerve contributions to the parasympathetic division?

Answer 18

Oculomotor, Facial, Glossopharyngeal, & Vagus

Question 19

What ganglion does the oculomotor nerve go to and what parasympathetic activities does it control?

Answer 19

Ciliary ganglion

Controls pupil constriction & ciliary muscles of lens for accommodation (near vision)

Question 20

What ganglion does the facial nerve go to and what parasympathetic activities does it control?

Answer 20

Pterygopalatine Ganglion
Controls lacrimal gland (tear activity), nasal cavity, & oral cavity
Submandibular Ganglion
Controls submandibular and sublingual glands (saliva)

Question 21

What ganglion does the Glossopharyngeal nerve go to and what parasympathetic activities does it control?

Answer 21

Otic Ganglion

Controls Parotid gland (saliva)

Question 22

What ganglion does the Vagus nerve go to and what parasympathetic activities does it control?

Answer 22

Multiple terminal and intramural ganglia
Heart- Decreases HR
Respiratory Organs- Decreases respiration
Bronchial Passages- Constricts, excites mucous production
Esophagus- Promotes swallowing and peristalsis
Abdominal Viscera- Promotes digestion

Question 23

What are the caudal nerve contributions of the parasympathetic division?

Answer 23

Pelvic and Sacral Splanchnic Nerves from S2-S4
Preganglionic parasympathetic axons form superior and inferior hypogastric plexus, then travel to organs and synapse with ganglia close to, or in the walls of the organs

Question 24

Areas of the body affected by Pelvic Splanchnic Nerve are _____?

Answer 24

Descending/sigmoid colon, rectum, most reproductive organs, urinary bladder, distal ureters, & erection