CH 13: ONLINE MC (spinal cord)

Which adjective best describes reflex responses?

automatic

The white matter of the spinal cord is composed primarily of

myelinated

The tapered inferior end of the spinal cord is called the

conus medullaris

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

filum terminale

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

Which structure provides motor innervation to the deep back muscles and receives sensory information from the skin of the back?

posterior ramus

Cell bodies of sensory neurons are housed in each

posterior root ganglion

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

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

The subarachnoid space contains ________, and the epidural space contains ________.

CSF; fat, connective tissue, and blood vessels

The anterior rami of spinal nerves T1-T11

are called intercostal nerves

The anterior root of a spinal nerve contains

axons of motor neurons only

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

cell bodies of autonomic motor neurons

The first step involved in a typical neural reflex is

activation of a receptor by a stimulus

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

Identify the meningeal layer immediately deep to the subdural space.

arachnoid

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

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, and pia mater

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

epidural space

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

funiculus

Axons cross from one side of the spinal cord to the other through a gray matter region called the

gray commissure

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?

phrenic

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

polysynaptic