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Ch. 13 Spinal Cord, Spinal Nerves, and Spinal Reflexes

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________ reflexes activate skeletal muscles.
Somatic
Blood vessels that supply the spinal cord run along the surface of the
pia mater.
The dorsal root of a spinal nerve contains
axons of sensory neurons.
The spinal cord consists of five regions and ________ segments.
31
Compared to the vertebral column, the spinal cord is
shorter
The ________ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament.
filum terminale
The ventral root of a spinal nerve contains
axons of motor neurons.
The subdural space lies between
the dura mater and the arachnoid mater.
The dorsal root ganglia mainly contain
cell bodies of sensory neurons.
The white matter of the spinal cord is mainly
myelinated axons.
The epidural space contains
connective tissue and blood vessels.
The layer of the meninges in direct contact with the spinal cord is the
pia mater.
Cerebrospinal fluid flows within the
subarachnoid space.
A dorsal and ventral root of each spinal segment unite to form a
spinal nerve.
Which of the following is true regarding an epidural block?
It affects only the spinal nerves in the immediate area of the injection.
It provides mainly sensory anesthesia.
It can be difficult to achieve in the upper cervical and midthoracic region.
It is commonly used as a method of pain control during labor and delivery.
all of the above
Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the
subarachnoid space.
In an adult, the conus medullaris is found at about
L1
The specialized membranes that surround the spinal cord are termed the
spinal meninges.
Spinal nerves are
both sensory and motor.
The tough, fibrous, outermost covering of the spinal cord is the
dura mater.
In meningitis,
CSF flow can be disrupted.
viruses can be the cause.
bacteria can be the cause.
inflammation of the meninges occurs.
all of the above
The spinal cord continues to elongate until about age
4 years old
Which of the following associations is incorrect?
11 thoracic spinal nerves (INCORRECT)
8 cervical spinal nerves
5 lumbar spinal nerves
5 sacral spinal nerves
1 coccygeal spinal nerve
The dura mater tapers inferiorly to form the ________.
coccygeal ligament
The ________ separates the dura mater from the walls of the vertebral canal.
epidural space
During the procedure known as a(n) ________, a needle is inserted into the subarachnoid space in the inferior lumbar region.
spinal tap
Mary is in an automobile accident and suffers a spinal cord injury. She has lost feeling in her lower body. Her doctor tells her that swelling is compressing a portion of her spinal cord. Which part of her cord is likely to be compressed?
ascending tracts
The white matter of the spinal cord contains
bundles of axons with common origins, destinations, and functions.
Somatic motor neurons in the spinal cord control all of the following muscles, except those that
move the neck.(NOT)
move the hand and fingers.
position the pectoral girdle.
move the forearm and hand.
move the arm.
The posterior horns of the spinal cord contain mainly
sensory nuclei.
Enlargements of the spinal cord occur
in those spinal segments that control the limbs.
Axons crossing from one side of the spinal cord to the other within the gray matter are found in the
gray commissures.
In the spinal cord, white matter is separated into ascending and descending tracts organized as
columns
The anterior horns of the spinal cord contain mainly
somatic motor nuclei.
Bill contracts a viral disease that destroys cells in the posterior gray horns in his spinal cord. As a result, which of the following would you expect?
loss of sensation in his torso
The gray horns of the spinal cord contain __________.
The gray horns contain all of these elements.
The gray horns of the spinal cord contain mainly
nerve cell bodies
A viral disease that destroys the cells of the anterior gray horn will
lead to muscle weakness or paralysis.
The ventral rami of spinal nerves C5 to T1 contribute fibers to the ________ plexus.
brachial
The ________ of each spinal nerve innervates the skin and muscles of the back.
dorsal ramus
If a person has a crush injury to the C3-C5 spinal segments, you would expect that he
might be unable to breathe on his own.
The outermost connective-tissue covering of nerves is the
epineurium.
If the dorsal root of a spinal nerve is severed,
sensory input would be blocked.
Muscles of the neck and shoulder are innervated by spinal nerves from the ________ region.
cervical
The ________ nerve, which arises in the cervical plexus, innervates the diaphragm.
phrenic
In which plexus does the ulnar nerve arise?
brachial
The region of the body surface monitored by a pair of spinal nerves is known as a(n) __________.
dermatome
The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the
endoneurium
In the condition ________, a virus infects dorsal root ganglia, causing a painful rash whose distribution corresponds to that of the affected sensory nerves as seen in their dermatomes.
shingles
The brachial plexus gives rise to all of the following nerves, except the
ulnar.
radial.
median.
phrenic.(NOT)
musculocutaneous.
The preganglionic fibers that connect a spinal nerve with an autonomic ganglion in the thoracic and lumbar region of the spinal cord form the
white rami communicantes.
The postganglionic fibers that connect an autonomic ganglion in the thoracic or lumbar region with the spinal nerve are
gray rami communicantes.
Postganglionic fibers of the autonomic nervous system that innervate internal organs do not rejoin the spinal nerve but form
autonomic nerves.
Spinal nerves from the sacral region of the cord innervate the ________ muscles.
leg
The ________ innervates the ventrolateral body surface, structures in the body wall, and the limbs.
ventral ramus
Each of the following nerves originates in the lumbar plexus, except the ________ nerve.
sciatic(NOT)
obturator
genitofemoral
femoral
saphenous
The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the
perineurium
The ventral rami form four major plexuses, including all of the following, except the ________ plexus.
brachial
sacral
cervical
lumbar
nuchal (NOT)
As the ________ nerve approaches the knee, it divides into two branches, the fibular nerve and the tibial nerve.
sciatic
The obturator nerve is distributed to the
adductors of the hip.
The nerve crucial for breathing that originates within the cervical plexus is called the ________ nerve.
phrenic
Reflexes can be classified according to all of the following, except
where information processing occurs.
whether they are sensory or motor. (NOT)
their development.
the complexity of the neural circuit.
the motor response.
The stretch reflex
is important in regulating muscle length and activated when a skeletal muscle lengthens.
A reflex arc always includes a(n) __________.
efferent axon, afferent axon, sensory receptor
All of the following are true of neural reflexes, except that they
involve at least two neurons.
cannot be modified by the brain. (NOT)
are automatic motor responses.
are the simplest form of behavior.
help preserve homeostasis.
Reflexes based on synapses formed during development are ________ reflexes.
innate
Visceral reflexes provide a mechanism for control of the abdominal muscles.
False
The reflex that prevents a muscle from exerting too much tension is the ________ reflex.
tendon
In which of the following would the delay between stimulus and response be greater?
a polysynaptic reflex (GREATER)
a monosynaptic reflex
Spinal interneurons inhibit antagonist motor neurons in a process called
reciprocal inhibition.
The most complicated spinal reflexes are called ________.
intersegmental reflex arcs
Which of the following is not true about a positive Babinski reflex?
normal in newborns
why you close your eyes when you sneeze (NOT)
abnormal in adults
flaring of the toes when the sole is stroked
a sign of injury to descending spinal tracts
The condition in which a person loses all feeling and movement of the arms and legs due to spinal cord injury is termed ________.
quadriplegia