Anatomy Quiz 1

The reflex that prevents a muscle from exerting too much tension is the __________ reflex.

tendon

Which of the following pairs is NOT properly matched?

lumbar spinal nerves: 4

The entire spinal cord is divided into __________ segments.

31

The spinal cord continues to elongate and enlarge until about age:

4 years

The following are the steps involved in a reflex arc: activation of a sensory neuron activation of a motor neuron response by an effector. arrival of a stimulus and activation of a receptor information processing The proper sequence of these steps is:

4, 1, 5, 2, 3

The ventral rami of spinal nerves C5 to T1 form the __________ plexus.

brachial

the ulnar nerve is found in which plexus?

brachial

The white matter of the spinal cord contains:

bundles of axons that share common origins, destinations, and functions

The reflex that complements a withdrawal reflex by making compensatory adjustments on the opposite side of the body receiving the stimulus is the __________ reflex.

crossed extensor

Spinal nerves from the sacral region of the cord innervate the __________ muscles.

leg

Spinal nerves are __________ nerves.

mixed

A nerve of the cervical plexus that innervates the diaphragm is the __________ nerve.

phrenic

Each of the following nerves is found in the lumbar plexus, EXCEPT the __________ nerve

sciatic

The specialized membranes that protect the spinal cord are termed:

spinal meninges

The dorsal and ventral roots of each spinal segment unite to form a:

spinal nerve

Muscles of the neck and shoulder are innervated by spinal nerves from the __________ region.

cervical

The ventral root of a spinal nerve contains:

axons of motor neurons

The dorsal root of a spinal nerve contains:

axons of sensory neurons

The dorsal root ganglia contain:

cell bodies of sensory neurons

The outermost connective tissue covering of spinal nerves is the:

epineurium

The adult spinal cord extends only to which vertebral level?

first or second lumbar

Axons crossing from one side of the spinal cord to the other within the:

gray commissures

The projections of gray matter toward the outer surface of the spinal cord are called:

horns

Enlargements of the spinal cord occur:

in segments of the spinal cord that control the limbs

The preganglionic fibers that connect a spinal nerve with a sympathetic ganglion in the thoracic and lumbar region of the spinal cord are the:

white ramus