Autonomic Nervous System (ANS) and Cervical Nerves

Question 1

Nuclei vs. Tract ( both are WITHIN CNS)

Answer 1

nuclei: collection of neuron cell bodies within the CNS; gray matter
tracts: axonal processes of neurons that travel collectively together to common destinations within the CNS; white matter

Question 2

Are afferent neurons unipolar or bipolar?

Answer 2

• Unipolar

bipolar: special sensory systems (olfaction, vision, taste)

Question 3

What shape are efferent neurons?

Answer 3

multipolar

Question 4

What are afferent neuron cell bodies in the CNS? In the PNS?

Answer 4

CNS: nerves
PNS: dorsal root ganglia

Question 5

What are efferent neuron cell bodies in the CNS? In the PNS?

Answer 5

CNS: nuclei
PNS: nerves

Question 6

What four cranial nerves contain autonomic neurons?

Answer 6

Oculomotor (CN III)
Facial (CN VII)
Glossopharyngeal (CN IX)
Vagus (CN X): innervates to lower body

Question 7

Where is the vagosympathetic trunk located?

Answer 7

in the neck, lies in the common carotid sheath; sympathetic portion has post and pre ganglionic axons that move cranially to structures in the head (synapse in cranial cervical ganglion)

-parasympathetic portion extends down to thorax and abdomen (synapse in terminal ganglion)

Question 8

Does the vagus nerve carry sympathetic or parasympathetic innervations? Where in the body?

Answer 8

pre-parasympathetic nervous system axons from the brain to the thorax and abdomen

Question 9

synapses of presynaptic ganglia onto post synaptic ganglia in sympathetic nervous system

Answer 9

(1) prevertebral ganglia: celiac, middle cervical, cranial cervical
(2) paravertebral ganglia
(3) cervicothoracic, middle cervical, cranial cervical (post sympathetic nervous system cell bodies)

Question 10

Where are the 8 cervical spinal nerves located?

Answer 10

CSN 1: above atlas
CSN2: between atlas and axis; near omotransversarius
CSN3:caudal to C2, cranial to C3 (same pattern for CSN 4-7)
CSN8: caudal to C7, cranial to T1

Question 11

Which CSN branches bifurcates into ventral branches? What nerves do those branches form?

Answer 11

CSN2

(1) greater auricular nerve
(2) transverse cervical nerve

Question 12

What is the accessory nerve? Where can it be seen?

Answer 12

Cranial nerve (XI)

-courses between the brachiocephalicus and the trapezius, dorsal to the omotransversarius