Nervous System

Question 1

Are visceral Afferent neurons motor or sensory neurons?

Which direction do they carry information?

Answer 1

Afferent = sensory
Carry info TO the CNS from viscera
= pain, stretch, distention, chemo and baro receptors (poorly localized)
(33)

Question 2

Are visceral Efferent neurons motor or sensory neurons?

Which direction do they carry information?

Answer 2

Efferent = motor (visceromotor)
Carry info from CNS to viscera
Innervates smooth and cardiac muscle and gland cells

Question 3

Does the Visceral Afferent or Visceral Efferent neurons form the ANS?

Answer 3

Visceral Efferent

33

Question 4

What are the 2 types of Visceral Efferent neurons?

Answer 4

Somatic efferent and Visceral efferent

Question 5

What is the major difference b/t somatic efferent neurons and somatic visceral neurons?

Answer 5

Somatic efferent neurons have only one neuron b/t the CNS and effector cell; The neuron soma is always in CNS.
Visceral efferent neurons have 2 neurons b/t CNS and effector cell (pre and post ganglionic); only the preganglionic soma is in CNS (34)

Question 6

Where do sympathetic fibers exit CNS?

Where do parasympathetic fibers exit CNS?

Answer 6

Sympathetic = T1-L2 (thoracolumbar)
Parasympathetic = S2,3,4 and CN III, VII, IX, X (craniosacral)
(34)

Question 7

Where are preganglionic sympathetic cell bodies located?

Answer 7

Gray matter of the Lateral Horn T1-L2

35

Question 8

Where are postganglionic sympathetic cell bodies located?

Answer 8

Paravertebral ganglia (make up sympathetic trunk) 
Prevertebral ganglia (near organs)

Question 9

How many paravertebral ganglia are typically present?

Answer 9

22-23 
2-3 cervical
12 thoracic
4 lumbar
4 sacral

Question 10

How do virtually all spinal nerves connect to the sympathetic trunk?

Answer 10

Gray rami communicantes

36

Question 11

Describe the sympathetic innervation to the head and neck structures.

Answer 11

Preganglionic sympathetic fibers enter chain through white rami communicantes of T1-T5 spinal nerves, ascend, and terminate on postganglionic neurons of cervical chain ganglia
(37)

Question 12

The superior cervical chain ganglion is made up of postganglionic axons at what cervical level?
Middle?
Inferior?

Answer 12

Superior = C1-C3/4 cervical spinal nerves
Middle = C4-6
Inferior = C7-8

Question 13

Where are prevertebral ganglia found?

Answer 13

Near organs they supply
*Include postganglionic sympathetic neurons
**The axons of these neurons are distributed primarily via arterial plexuses to effector cells
(37)

Question 14

How are postganglionic neurons of the prevertebral ganglion innervated?

Answer 14

Innervated by preganglionic sympathetic neurons whose fibers traverse through the sympathetic trunk w/out synapse and travel through splanchnic nerves to the specific ganglia
(37)

Question 15

Where is the celiac ganglion?

What does it innervate?

Answer 15

Celiac ganglion found near celiac artery
Innervates foregut and midgut
Receives preganglionic fibers from greater splanchnic nerves
(37)

Question 16

Where is the superior mesenteric and aorticorenal ganglia?

Where do they innervate?

Answer 16

Near superior mesenteric and renal arteries
Innervate midgut
Receive preganglionic fibers from lesser splanchnic nerves

Question 17

Where is the inferior mesenteric ganglion?

What does it innervate?

Answer 17

Near inferior mesenteric artery
Innervate hindgut
Receives preganglionic fibers from lumbar splanchnic nerves

Question 18

Describe the functions of the sympathetic division of ANS as it relates to 1) cutaneous structures (arteries of skin, sweat glands, arrector pili muscles)

2) Arteries of skeletal muscle
3) Pupils
4) heart rate/blood pressure

Answer 18

1) Vasoconstrict arteries of skin, increase sweat gland secretion, activate arrector pili
2) Vasodilate arteries in skeletal muscle
3) Dilate pupils
4) Increase heart rate and blood pressure
(40)

Question 19

Where are preganglionic parasympathetic neuron cell bodies located?

Answer 19

Brain-exit via CN III, VII, IX, X
and spinal cord-exit via spinal nerves S2,3,4
(41)

Question 20

Are preganglionic parasympathetic axons myelenated?

Answer 20

Yes

41

Question 21

Where are postganglionic parasympathetic neuron cell bodies located?

Answer 21

Parasympathetic ganglia = near/in the wall of organs they innervate
(41)

Question 22

How many pairs of parasympathtic ganglia are there? What are they?

Answer 22

Four parasympathetic ganglia
1) Ciliary - receives preganglionic fibers from CN III
2) Submandibular - receives preganglionic fibers from CN VII
3) Sphenopalatine - receives preganglionic fibers from CN VII
4) Otic - receives preganglionic fibers from CN IX
(41)

Question 23

What type of neurons are found in Auerbach’s plexus (smooth muscle of GI tract); Meissner’s (submucosal plexus); Cardiac plexus; Pulmonary plexus; Pelvic plexus?

Answer 23

Postganglionic Parasympathetic fibers. These are all examples of intramural ganglia
(42)

Question 24

Where are preganglioinic fibers to intramural ganglia from?

Answer 24

CN X and spinal nerves S2,3,4

Question 25

Are postganglionic parasympathetic axons myelenated?

Answer 25

No

42

Question 26

Describe functions of the Parasympathetic Nervous System as it relates to:

1) Heart rate/blood pressure
2) Glands of digestion
3) Peristalsis of the gut
4) Pupils

Answer 26

1) Decrease HR and BP
2) Increase glands of digestion (salivary/GI)
3) Increase peristalsis of the gut
4) Constrict pupils
(42)

Question 27

Visceral pain afferent fibers enter the spinal cord through what spinal nerves?

Answer 27

T1-L2

44

Question 28

Visceral physiological (chemoreception, baroreception, distention) afferent fibers enter the spinal cord through…?

Answer 28

CN IX, X and S2,3,4

44