Anatomy (ANS - 11/3) Flashcards Preview

Skin MS: Week 2 > Anatomy (ANS - 11/3) > Flashcards

Flashcards in Anatomy (ANS - 11/3) Deck (44)
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1

ANS (Visceral motor system) innervates __________

Smooth muscle, cardiac muscle, glands

2

How many neurons in ANS system

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

3

Preganglionic cell bodies

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

4

Postganglionic cell bodies

Autonomic ganglion (depending on para/sympathetic) - multipolar

5

Sympathetic originates from preganglionic cell neurons having cell bodies in _____

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

6

Parasympathetic have cell bodies in ____

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

7

Where do preganglionic sympathetic neurons exit from lateral horn?

Ventral root (motor) to join spinal nerve

8

Sympathetic preganglionic neuron pathway

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

9

Lateral Horn

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

10

White communicating ramus

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

11

4 Options for Preganglionic Sympathetic neurons

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

12

Postganglionic sympathetic cell bodies

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

Cells of adrenal medulla homologous to postganglionic neurons

13

Cervical paravertebral ganglia

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

14

How do postganglionic axons leave paravertebral ganglia?

Gray rami communicans

15

How many pairs of gray rami?

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

16

Gray rami communicans

31 pairs
Unmyelinated axons from postganglionic sympathetic axons --> spinal nerves

17

Cardiopulmonary sympathetic nerves

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

18

Cephalic arterial rami (Sym)

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

19

Prevertebral/preaortic ganglia

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)

20

Splanchnic nerves

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

21

What nerves supply prevertebral ganglia with preganglionic neurons?

Splanchnic nerves

22

Adrenal gland (suprarenal gland(

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

23

What does preganglionic Sym neuron release - onto what receptor

Acetylcholine onto nicotinic receptor of PostG sym neuron RO adrenal medulla

24

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

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

25

Location of PreG parasympathetic cell bodies

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

26

Postganglionic parasympathetic cell bodies

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

27

What do preG para neurons release? Receptors?

Acetylcholine to Nicotinic receptors on postG

28

What do postG para neurons release? Receptors?

Acetylcholine to Muscarinic receptors on organ

29

Enteric nervous system overview

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

30

Where are postganglionic parasympathetic nerve cell bodies located?

Cranial nerve and terminal ganglia