Anatomy (ANS - 11/3)

Question 1

ANS (Visceral motor system) innervates __________

Answer 1

Smooth muscle, cardiac muscle, glands

Question 2

How many neurons in ANS system

Answer 2

2 (preganglionic cell body in CNS and postganglionic cell body in peripheral ganglion - motor)

Question 3

Preganglionic cell bodies

Answer 3

CNS - multipolar
Sympathetic in Lateral Horn (T1-L2/3)
Parasympathetic in Brain stem (CN III, VII, IX, X) or sacral region S2-S4

Question 4

Postganglionic cell bodies

Answer 4

Autonomic ganglion (depending on para/sympathetic) - multipolar

Question 5

Sympathetic originates from preganglionic cell neurons having cell bodies in _____

Answer 5

Lateral gray horn (intermediolateral cell column) of spinal cord levels T1 to L2/3

Question 6

Parasympathetic have cell bodies in ____

Answer 6

Cranial nerve nuclei III, VII, IX, X and spinal cord segments
S2,3,4

Question 7

Where do preganglionic sympathetic neurons exit from lateral horn?

Answer 7

Ventral root (motor) to join spinal nerve

Question 8

Sympathetic preganglionic neuron pathway

Answer 8

Lateral horn –> ventral root –> spinal cord –> communicating white ramus –> sympathetic chain to synapse with postganglionic OR travel to prevertebral ganglion

Question 9

Lateral Horn

Answer 9

T1-L2/3
Sympathetic preganglionic cell bodies
Intermediolateral cell column

Question 10

White communicating ramus

Answer 10

Spinal nerve to sympathetic chain ganglia (preganglionic sympathetic fibers - axons)
Myelinated axons
14 pairs (28 total) from T1-L2
Also contain visceral sensory nerves

Question 11

4 Options for Preganglionic Sympathetic neurons

Answer 11

1. Terminate with postsynaptic neuron of paravertebral ganglion at that spinal cord level
2. Ascend to terminated at higher paravertebral level
3. Descend to terminate at lower paravertebral leve
4. Traverse sympathetic trunk w/o terminating –> splanchnic (visceral) nerves –> prevertebral ganglia (pre-aortic) or adrenal gland

Question 12

Postganglionic sympathetic cell bodies

Answer 12

Paravertebral (sympathetic chain) ganglia OR prevertebral (preaortic) ganglia

Cells of adrenal medulla homologous to postganglionic neurons

Question 13

Cervical paravertebral ganglia

Answer 13

3 ganglia (per side) --> 8 cervical spinal nerves 
Superior cervical ganglion (largest) --> supply head also, Middle, Inferior

Question 14

How do postganglionic axons leave paravertebral ganglia?

Answer 14

Gray rami communicans

Question 15

How many pairs of gray rami?

Answer 15

31 pairs - communicate with 31 pairs of spinal nerves (cervical, thoracic, lumbar, sacral and coccygeal)

Question 16

Gray rami communicans

Answer 16

31 pairs

Unmyelinated axons from postganglionic sympathetic axons –> spinal nerves

Question 17

Cardiopulmonary sympathetic nerves

Answer 17

From paravertebral ganglia to supply postG sym fibers to heart and lungs (cardiac, pulmonary, aortic plexuses)
From middle/inferior cervical paravertebral panglia or in upper 5 thoracic paravertebral ganglia

Question 18

Cephalic arterial rami (Sym)

Answer 18

postS sym fibers to head, travel with blood vessels, from superior cervical ganglion

Question 19

Prevertebral/preaortic ganglia

Answer 19

3 main ones - celiac ganglion, superior mesenteric ganglion, inferior mesenteric ganglion
Also a renal ganglion closely associated with superior mesenteric ganglion
Receive preganglionic sympathetic input over splanchnic nerves (visceral)

Question 20

Splanchnic nerves

Answer 20

Carry preganglionic fibers from sypmathetic chain to prevertebral ganglia - postganglionic neruons in prevertebral G send axons to organ of innervation

Question 21

What nerves supply prevertebral ganglia with preganglionic neurons?

Answer 21

Splanchnic nerves

Question 22

Adrenal gland (suprarenal gland(

Answer 22

Equivalent to postganglionic neuron
Release primarily epinephrine into vascular system
Preganglionic neurons pass through paravertebral and prevertebral ganglia to synapse at AM.

Question 23

What does preganglionic Sym neuron release - onto what receptor

Answer 23

Acetylcholine onto nicotinic receptor of PostG sym neuron RO adrenal medulla

Question 24

What does PostG sym neuron release? What do receptors do?

Answer 24

Norepinephrine onto
a1, b1 - excitatory
a2, b2 - inhibitory

Question 25

Location of PreG parasympathetic cell bodies

Answer 25

Brain stem (for cranial nerves III, VII, IX, X) and sacral spinal cord S2-S4 (for spinal nerves) LONG - to postG near organ of innervation

Question 26

Postganglionic parasympathetic cell bodies

Answer 26

Closer to organ of innervation In ganglia In head - named, distinct Vagus nerve/pelvic nears - terminal ganglia near organs

Question 27

What do preG para neurons release? Receptors?

Answer 27

Acetylcholine to Nicotinic receptors on postG

Question 28

What do postG para neurons release? Receptors?

Answer 28

Acetylcholine to Muscarinic receptors on organ

Question 29

Enteric nervous system overview

Answer 29

Nerve cell bodies of myenteric and submucosal nerve plexus Postganglionic Para neurons Terminal ganglia

Question 30

Where are postganglionic parasympathetic nerve cell bodies located?

Answer 30

Cranial nerve and terminal ganglia

Question 31

Preganglionic Symp Neurons to the head have cell bodies in _________

Answer 31

spinal cord segments T1-T2

Question 32

#White Rami communicantes present in body

Answer 32

28 (14*2)

Question 33

PostG symp neurons to the head have their cell bodies located in _________

Answer 33

paravertebral ganglia

Question 34

Paravertebral ganglia receive innervation via

Answer 34

white rami

Question 35

What nerves supply prevertebral ganglia with preganglionic neurons

Answer 35

splanchnic nerves

Question 36

Gray rami communicantes

Answer 36

62 (31*2)

Question 37

What is the location of postG sym nerve fibers suppling the head?

Answer 37

Superior cervical ganglion

Question 38

Where are cell bodies of cardiopulmonary nerves (SYM)

Answer 38

Paravertebral plexus

Question 39

Ways postganglionic axons leave paravertebral ganglia

Answer 39

Gray rami communicans --> spinal nerves Cephalic arterial branches/periarterial sym plexus --> head region Cardiopulmonary nerves --> heart, lungs, esophagus (cardiac/pulmonary/aortic plexuses)

Question 40

Why are cardiopulmonary splanchnic nerves postganglionic white abdominopelvic splanchnic nerves preG?

Answer 40

CPS come from sympathetic chain ganglia where they synapsed, whereas APS do NOT synapse when they run through SCG and synapse in the prevertebral ganglia

Question 41

Adrenal medulla cells

Answer 41

Chromaffin - release primarily epinephrine

Question 42

Exception to rule that postG sym release norepinephrine

Answer 42

PostG sym release acetylcholine to innervate sweat glands, smooth muscle in some arteries (i.e. skeletal muscle)

Question 43

vagus nerve

Answer 43

CN X Preganglionic neurons to postganglionic parasym neurons associated w/ heart, lungs, most of abdominal viscera Largest source of preganglionic para nerve fibers

Question 44

Pelvic splanchnic nerves

Answer 44

output of S2-S4 preganglionic to postG parasym --> distal 1/3 of large intestine, pelvic viscera, genitalia