Spinal Nerves

In males, what reflex protects a testis from damage by elevating it when the medial side of the thigh is briskly stroked?

cremasteric

Within the cauda equina is a thin strand of pia mater called the

filum terminale

White matter of the spinal cord is partitioned into ____________, each containing both ascending and descending ____________.

funiculi; tracts

Which of the following is not generally involved in a reflex?

inhibition of an effector by a stimulus from a motor neuron

Which spinal cord components contain cell bodies of interneurons and axons of sensory neurons?

posterior horns

Cell bodies of sensory neurons are housed in each

posterior root ganglion

Damage to which nerve would likely cause the most severe dysfunction in both the urinary and reproductive systems?

pudenal

In a freak golfing accident, Jim damaged a nerve in his arm and now has trouble extending his forearm, wrist, and fingers. Which nerve did he damage?

radial

All of the following branch from the lumbar plexus except the

sciatic nerve

The patterns of ____________ innervation of each pair of spinal nerves, termed ____________, do not match the sensory distribution of any terminal nerve in the limbs because of recombinations in the plexuses.

somatic sensory; dermatomes

Within each intervertebral foramen, an anterior root and its corresponding posterior root unite to form a

spinal nerve

A familiar type of monosynaptic reflex that monitors and regulates the length of skeletal muscle is the

stretch reflex

The roots of the brachial plexus are actually

the anterior rami of spinal nerves

Which nerve innervates the posterior thigh and leg muscles, plantar foot muscles, and skin of the sole of the foot?

tibial

Which nerve is most likely to be injured by fractures or dislocations of the elbow (or by an extra hard hit to the "funny bone")?

ulnar

The anterior funiculi are interconnected by the

white commissure

The outer region of the spinal cord, composed primarily of myelinated axons, is called the

white matter

Normal for infants but indicative of CNS damage in adults, the ____________ is essentially a reversal of the ____________ reflex.

Babinski sign; plantar

The spinal nerves inferior to ____________ exit below the vertebra of the same number.

C8

Which spinal meningeal layer is sandwiched between a potential space and a very significant space occupied by connective tissue fibers and cerebrospinal fluid?

arachnoid

The anterior rami of spinal nerves T1-T11

are called intercostal nerves

The sensory nuclei of the spinal cord contain which type of neuron cell bodies?

association

Which adjective best describes reflex responses?

autonomic

Which terminal branch of the brachial plexus innervates the skin just distolateral to the acromion, as well as an abductor and a lateral rotator of the arm?

axillary nerve

Loss of sensation in a single dermatome on one side of the body could indicate damage to a spinal nerve or to

a posterior root ganglion

The word root commissura most nearly means

a seam

The first step involved in a typical neural reflex is

activation of a receptor by stimulus

Where does the adult spinal cord end?

all of the above at the tip of the conus medullaris above filum terminale at the level of L1

Which branches of spinal nerves innervate the limbs and the anterolateral portions of the trunk?

anterior rami

Which structure contains motor axons only?

anterior root

Which structures would not be found in the anterior horns of the spinal cord?

cell bodies of autonomic motor neurons

The posterior and anterior roots of the ____________ must elongate because the spinal cord stops growing before the vertebral column does.

cauda equina

What is the collective name for all of the axons that project inferiorly from the spinal cord?

cauda equina

The lateral horns found in the T1-L2 regions of the spinal cord contain

cell bodies of autonomic motor neurons

The substance that fills the subarachnoid space is

cerebrospinal fluid

Branches of which plexuses innervate anterior neck muscles, the skin of the neck, and parts of the head and shoulders?

cervical

The four principal nerve plexuses are the

cervical, brachial, lumbar, and sacral

Helping to prevent side-to-side and inferior movement of the spinal cord are paired ____________ that connect the pia mater to the dura mater.

denticulate ligaments

What are the paired, triangular extensions of the pia mater that help anchor the spinal cord laterally to the dura mater?

denticulate ligaments

Which term describes the specific region of skin monitored by a single spinal nerve?

dermatome

The tough, protective ____________ extends between adjacent vertebrae to fuse with the connective tissue surrounding the spinal nerves.

dura mater

The spinal cord meninges, in order from the outermost to the innermost, are the

dura mater, arachnoid mater, pia mater

Between the dura mater and the inner walls of the vertebrae is the

epidural space

Bob had polio as a child and now drags his right leg slightly when he walks because of weakness in flexing his hip and extending his knee. In addition, his leg swings outward slightly with each step, and he has difficulty in crossing his right leg over his left. These all result from damage to which nerve?

femoral

Although extending from the end of the spinal cord, the ____________ contains no neural fibers, only fibrous connective tissue

filum terminale

In the spinal cord, a ____________ is to a tract as a horn is to a nucleus.

funiculus

Clinically, a ____________ reflex accompanied by ____________ strongly indicates brain or spinal cord injury.

hyperactive; clonus

Which branches of the lumbar plexus innervate muscles of the anterior abdominal wall?

iliohypogastric and ilioinguinal nerves

If its receptor and effector are on the same side of the body, a reflex arc is termed ____________; if on opposite sides, it is ____________.

ipsilateral; contralateral

Which body regions are innervated by the lumbar enlargement of the spinal cord?

lower limbs

Nerves from the brachial plexuses innervate the

pectoral girdles and upper limbs

Of the following, which nerve ranges farthest from its roots in the cervical plexus and is most vital to your health?

phernic

Fibers of the ____________ intertwine on one side with those of another meninx, and on the other, with glial cells.

pia mater

If a reflex arc involves a single interneuron, it is classified as

polysynaptic

"Crutch palsy" and "drunkard's paralysis" both refer to conditions resulting from injury to the ____________ of the brachial plexus.

posterior chord