SM49_Somatic Nervous System

Question 1

Particular properties of sensory/afferent neurons

Answer 1

Pseudounipolar: one process is divided into a very long dendrite and a short axon

Cell bodies are in dorsal root ganglia

Unusual in that dendrite is myelinated

Question 2

Particular properties of somatomotor/efferent neurons

Answer 2

Multipolar: many dendrites and an axon

Cell bodies in ventral horn of spinal cord

Found in spinal nerves

Question 3

Part of embryo that contributes to formation of the most inferior part of spinal cord

Answer 3

Caudal eminence

Question 4

Defects in neural tube formation from least to most severe (4)

Answer 4

spina bifida occulta, myelomeningocele, meningocele, rachischisis

Question 5

Spinal nerves consist of ____

Answer 5

general sensory neurons, somatomotor neurons, and postsynaptic sympathetic neurons

Question 6

Compared to the deep body wall spinal nerves, spinal nerves supplying the superficial body wall do not have what kind of nerves?

Answer 6

somatomotor neurons (bc no skeletal muscle exists in superficial body wall)

Question 7

Cell body locations of:

1) somatomotor neurons in spinal nervs
2) general and visceral sensory neurons in spinal nerves
3) neurons which relay peripheral sensory impulse to the brain or ventral horn

Answer 7

1) ventral horn
2) dorsal root ganglia
3) dorsal horn

Question 8

Three meninges from outermost layer to most inner layer

Answer 8

Dura mater (outer), arachnoid (middle), pia mater (inner)

Question 9

Conus medularis

Answer 9

termination of the spinal cord at the L1 vertebral level

Question 10

The _________ L2 is the level of the exit of spinal nerve L2, while _________ L2 is the origin of the spinal nerve L2

Answer 10

Vertebral body L2, spinal cord segment L2

Question 11

“Tooth-like” pia mater extensions which anchor the cord to the vertebral column

Answer 11

Denticulate ligaments

Question 12

Inferior pia mater extension from the cord to the coccyx which anchors the cord inferiorly

Answer 12

Filum terminale

Question 13

Dorsal and ventral roots below the end of the cord coursing toward their appropriate level of exit from the vertebral column

Answer 13

Cauda Equina

Question 14

True or False: Sacral nerve blocks can be either epidural or subarachnoid

Answer 14

False; sacral nerve blocks must be epidural because the subarachnoid space ends at S1

Question 15

True or False: Epidural blocks can be done in both the sacral and lumbar regions

Answer 15

True