Nervous System

Question 1

Most neurons are ___

Answer 1

Multipolar, excitation occurs at cell body

Question 2

unipolar neuron: where is it found? where is the cell body? sensory or motor?

Answer 2

found in spinal ganglia, sensory neurons. cell body is along the axon.

Question 3

Nerve is enveloped by ___

Answer 3

connective tissue (epineurium, perineurium, endoneurium)

Question 4

Root is enveloped by

Answer 4

Meninges. nerve adjacent to CNS

Question 5

In the PNS, there are ___ pairs of cranial nerves and ___ pairs of spinal nerves

Answer 5

12, 36

Question 6

Dorsal and ventral roots combine to form a ____

Answer 6

spinal nerve

Question 7

spinal nerve is found within the ___

Answer 7

vertebral foramen

Question 8

dorsal root contains afferent or efferent axons?

Answer 8

afferent (sensory), site of spinal ganglion

Question 9

4 branches of spinal nerve:

Answer 9

meningeal branch (short, sensory to meninges), ramus communicans (connects to sympathetic trunk and innervates viscera), ventral (big, hypaxial mm and lateral/ventral cutaneous nn), dorsal (medial/lateral braches. epaxial mm. and dorsal cutaneous nn)

Question 10

General Somatic Afferent (GSA)

Answer 10

This sensory nerve fiber type has receptors in skin, muscles, tendons, and joints

Question 11

This sensory nerve fiber type has receptors in viscera

Answer 11

General Visceral Efferent (GVE)

Question 12

Two nerve fiber types

Answer 12

Afferent (Sensory) and Efferent (Motor)

Question 13

Afferent nerves have cell bodies in ____ while efferent nerves have cell bodies in ____

Answer 13

spinal ganglia, spinal cord (or autonomic ganglia)

Question 14

Visceral efferent innervates ___

Answer 14

cardiac muscle, smooth muscle, glands

Question 15

somatic efferent innervates ___

Answer 15

skeletal muscle

Question 16

ANS consists of what type of nerve fibers? What about it’s neurons makes it unique?

Answer 16

Visceral Efferent (VE) pathway (sometimes GVA is lumped in there). It has TWO multipolar neurons

Question 17

VE Pathway. where are first and second neuron located?

Answer 17

first neuron is in CNS/spinal cord and second neuron is in autonomic ganglia in PNS.

Question 18

T/F: each skeletal muscle innervated by one nerve

Answer 18

False. each myotome is innervated by one nerve, but they overlap during development, so each muscle is composed of multiple myotomes. Limb muscles are only innervated by one nerve, but that’s a branch of a regional nerve which have axons from ventral branches of multiple spinal nerves. this is what makes a “plexus”