Autonomic Nervous System Flashcards Preview

Anatomy Exam II > Autonomic Nervous System > Flashcards

Flashcards in Autonomic Nervous System Deck (15)
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1
Q

preganglionic neuron releases what NT?

A

acetylcholine

2
Q

postganglionic neuron releases what NT?

A

acetylcholine or norepinephrine (to excite)

3
Q

What are differences between Sympathetic and Parasympathetic ANS with regard to: distribution, preganglionic origin, postganglionic NT, function?

A

sympathetic (thoracolumbar) is fight or flight, pregang is in thoracolumbar SC, postgang is usually adrenergic, so it releases norepinephrine.

Parasympathetic ANS (craniosacral) is routine visceral/head actions, pregang in sacral SC and brainstem?, postgang is always cholinergic.

4
Q

Why are muscle vessels dilated under cholinergic control (while cutaneous are constricted) during a sympathetic response?

A

shifting blood flow to more important areas, but not sure why it’s cholinergic.

5
Q

Parasympathetic does not innervate:

A

cutaneous vessels, muscle vessels, and sweat glands

6
Q

3 parasympathetic nerve pathways

A
Cranial Nerves (later)
C10 nerve (Vagus Nerve)
Sacral Spinal Cord
7
Q

Vagus Nerve Parasympathetic Pathway

A

Parasympathetic. pregangs travel down axon and synapse on “terminal ganglia” in abdomen and thorax. postgangs then go to submucosal or myenteric plexuses to innervate smooth m., cardiac m. or gland.

8
Q

Sacral spinal cord Parasympathetic Pathway

A

Parasympathetic. S1-S3 innervates pelvic viscera. Pregang goes from sacral cord through ventral root, spinal nerve, ventral branch, sacral plexus, pelvic nerve. then synapses on pelvic plexus and then postgangs branch to pelvic viscera.

9
Q

route of all sympathetic nerves

A

SC –> dorsal/ventral root –> spinal nerve –> ramus communicans –> sympathetic trunk

10
Q

Head Sympathetic Pathway

A

Ventral Root –> Spinal Nerve –> Ramus Communicans –> SYmpathetic Trunk

–> ansa subclavia –> cervical sympathetic trunk

synapses on cranial cervical ganglion

postgang goes down carotid arteries and branches.

11
Q

Neck Sympathetic Pathway

A

Ventral Root –> Spinal Nerve –> Ramus Communicans –> Sympathetic Trunk

Synapses on the cervicothoracic ganglion

postgang:
vertebral nerve –> rami communicantes –> cervical spinal nerve –> dorsal/ventral branches to muscles and skin

12
Q

Body Wall/Limbs/Tail Sympathetic Pathway

A

Ventral Root –> Spinal Nerve –> Ramus Communicans –> Sympathetic Trunk

Synapses on sympathetic trunk ganglia (paravertebral ganglia)

Postgangs:
rami communicantes –> spinal nerve –> dorsal/ventral branches to muscle/skin

13
Q

Thoracic Viscera Sympathetic Pathway

A

Ventral Root –> Spinal Nerve –> Ramus Communicans –> Sympathetic Trunk

Synapse at cervicothoracic and middle cervical ganglia

postgang: cardiosympathetic nerves branch from ansa subclavia and with vagus nerve.

14
Q

Abdominal Viscera Sympathetic Pathway

A

…sympathetic Trunk –> splanchnic n

synapse at prevertebral ganglia - celiac, cranial mesenteric, caudal mesenteric, renal, and gonadal ganglia.

post gang go tonerve plexuses on abdominal arteries

15
Q

Pelvic Viscera Sympathetic Pathway

A

…sympathetic trunk –> lumbar splanchnic n –> caudal mesenteric plexus

synapses at caudal mesenteric ganglion

postgang:
hypogastric n –> pelvic plexus –> branches to pelvic viscera