CHAPTER 13

Question 1

“Somatosensory” does not refer to sensory signals from_________.

Answer 1

the viscera

Question 2

A ganglion is a swelling along a nerve containing the cell bodies of peripheral neurons.
True or False

Answer 2

True

Question 3

A ganglion is a_________.

Answer 3

cluster of cell bodies in the PNS

Question 4

A mixed nerve consists of both_________ and_________.

Answer 4

afferent; efferent fibers

Question 5

A reflex in which the sensory input and motor output are on opposite sides of the spinal cord is called_________.

Answer 5

contralateral

Question 6

A simple spinal reflex typically involves how many neurons?

Answer 6

three

Question 7

A stretch reflex is often accompanied by reciprocal inhibition.
True or False

Answer 7

True

Question 8

A_________ is a cordlike organ composed of numerous________

Answer 8

nerve; axons

Question 9

Cell bodies of the anterior root are located in the_________.

Answer 9

gray matter

Question 10

Cerebrospinal fluid fills the space between the_________.

Answer 10

arachnoid mater and pia mater

Question 11

Epidural anesthesia is introduced to the epidural space between the_________ to block pain signals during pregnancy.

Answer 11

dural sheath and vertebral bones

Question 12

Eyes and ears are innervated by_________ fibers.

Answer 12

special

Question 13

Interneurons are located in the_________.

Answer 13

spinal cord

Question 14

Many upper motor neurons synapse with lower motor neurons in the_________.

Answer 14

anterior horn

Question 15

Motor commands are carried by_________ from the brain along the spinal cord.

Answer 15

descending tracts

Question 16

Nerve fibers are insulated from one another by_________.

Answer 16

endoneurium

Question 17

Nerve fibers in a given white matter tract are similar in origin, destination, and function.
True or False

Answer 17

TRue

Question 18

Reflex arcs that only use two neurons are called_________ reflex arcs.

Answer 18

monosynaptic

Question 19

Second-order neurons synapse with third-order neurons in the_________.

Answer 19

thalamus

Question 20

Sensory stimuli enter the spinal cord via_________.

Answer 20

afferent axon

Question 21

Somatic reflexes are responses of skeletal, smooth, and cardiac muscles.
True

False

Answer 21

False

Question 22

The bundle of nerve roots that occupy the vertebral canal from L2 to S5 is called the_________.

Answer 22

cauda equina

Question 23

The cervical plexus is the origin of the_________ nerve(s).

Answer 23

phrenic

Question 24

The connective tissue that surrounds a nerve fascicle is called the _________.

Answer 24

perineurium

Question 25

The fibers that carry the action potentials that cause skeletal muscle to contract are_________.

Answer 25

alpha motor neurons

Question 26

The middle layer of the meninges is called the_________.

Answer 26

arachnoid mater

Question 27

The upper motor neurons that control skeletal muscles begin with a body in the_________.

Answer 27

precentral gyrus of the cerebrum

Question 28

There are_________ pairs of spinal nerves.

Answer 28

31

Question 29

Voluntary motor impulses leave the spinal cord via the_________ of gray matter.

Answer 29

anterior horn

Question 30

Which of the following branches of a spinal nerve has the cell bodies of only sensory neurons?

Answer 30

Posterior (dorsal) root

Question 31

Which of the following fractures would be the least likely to cause a spinal cord injury?

Answer 31

A fracture of vertebra L4

Question 32

Which of the following is comprised of anterior rami from C5-T1?

Answer 32

Brachial plexus

Question 33

Which of the following is contained within gray matter?

Answer 33

Cell bodies, dendrites, and proximal parts of axons of neurons

Question 34

Which of the following is not a distal branch of the spinal nerve?

Answer 34

Posterior root

Question 35

Which of the following is not a function associated with the spinal cord?

Answer 35

Protect neurons in both the ascending and descending tracts

Question 36

Which of the following is not a property of reflexes?

Answer 36

Reflexes do not require a stimulus.

Question 37

Which of the following is not considered a region of the spinal cord?

Answer 37

Pelvic

Question 38

Which of the following nerves originates in the lumbosacral plexus?

Answer 38

Sciatic

Question 39

Which of the following sensory functions involves neurons in the posterior root ganglion?

Answer 39

Touch

Question 40

Which of the following structures is the richest in lipid content?

Answer 40

White matter

Question 41

Which one of the following best describes the order of a somatic reflex?

Answer 41

Somatic receptor → afferent nerve fiber → interneuron → efferent nerve fiber → skeletal muscle