Nervous System

Question 1

What are nuclei?

Answer 1

collections of neuron cell bodies in the CNS

Question 2

What are tracts?

Answer 2

bundles of nerve fibers/axons that are traveling together towards a common destination within the CNS

Question 3

Describe afferent neuron

Answer 3

• relay sensory input to the CNS
• usually bipolar or unipolar
• cell bodies within PNS

Question 4

Describe efferent neuron

Answer 4

• relay motor output from the CNS
• usually multipolar
• cells bodies within the CNS

Question 5

Where do efferent somatic nerves synapse, and where do efferent visceral nerves synapse?

Answer 5

• somatic synapse directly on target tissue

- visceral synapse onto a second neuron, which then synapses onto the target tissue

Question 6

Describe the composition of the phrenic nerves and their target tissue

Answer 6

• supply somatic innervation to diaphragm

- contain motor, sensory, and sympathetic nerve fibers

Question 7

Where is the vagosympathetic trunk, and what does it consist of? What types of nerve fibers?

Answer 7

• lies in the neck, in the carotid sheath
• contains vagus nerve and sympathetic trunk
• transmits parasympathetic pre-ganglionic nerve fibers caudally, and somatic pre-ganglionic nerve fibers cranially

Question 8

Where is the sympathetic trunk and what does it consist of? What types of nerve fibers?

Answer 8

• runs craniocaudal, lateral to the vertebral column
• ganglion present where each ramus joins from spinal nerve
• ganglia contain sympathetic post-ganglionic cell bodies

Question 9

What is the composition of the vagus nerves?

Answer 9

• contain parasympathetic pre-ganglionic nerve fibers

- also contains somatic nerve fibers that leave via the recurrent laryngeal nerves

Question 10

What do the middle cervical and cervicothoracic ganglia contain?

Answer 10

sympathetic post-ganglionic cells bodies

Question 11

What is the function of the Ansa Subclavia?

Answer 11

transmits sympathetic pre-ganglionic fibers to middle cervical ganglion

Question 12

What is the celiacomesenteric ganglion and plexus, and what does it contain?

Answer 12

• celiac and cranial mesenteric ganglia contain sympathetic post-ganglionic cell bodies
• plexus transmits sympathetic post-ganglionic fibers

Question 13

What is the composition of the splanchnic nerves?

Answer 13

sympathetic pre-ganglionic fibers

Question 14

What does the caudal mesenteric ganglion contain?

Answer 14

sympathetic post-ganglionic cell bodies

Question 15

What is the composition of the hypogastric nerves?

Answer 15

sympathetic post-ganglionic fibers

Question 16

What is the composition of the pelvic nerves?

Answer 16

parasympathetic pre-ganglionic fibers

Question 17

What does the pelvic plexus contain?

Answer 17

parasympathetic pre-ganglionic fibers (from pelvic nerves) and sympathetic post-ganglionic fibers (from hypogastric nerves)

Question 18

Describe the cell body location and fiber distribution for the sympathetic neurons

Answer 18

• pre-ganglionic cell bodies are within the CNS, and their axons synapse in a second ganglion in the PNS
• post-ganglionic cells bodies are within the second ganglia, and the axons synapse on the target organ/tissue

Question 19

Describe the cell body location and fiber distribution for the parasympathetic neurons

Answer 19

• pre-ganglionic cells bodies are within the CNS, and the axons synapse on a ganglion on the target organ/tissue
• post-synaptic cell bodies are within the ganglia on the target organ, and the axons synapse on the organ

Question 20

Which cranial nerves contain autonomic components?

Answer 20

• oculomotor (CN III)
• facial (CN VII)
• glossopharyngeal (CN IX)
• vagus (CN X)