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