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