Anatomy 12
If a person has a crush injury to the C3-C5 spinal segments, you would expect that he
is unable to breathe on his own
The ventral rami form four major plexuses including all of the following except the ______ plexus
nuchal
As the ________ nerve approaches the knee, it divides into two branches, the fibular nerve and the tibial nerve.
sciatic
The spinal cord continues to elongate until about age
4 years
What is the function of the structure labeled "14"
Visceral motor
The ________ reflex complements the flexor reflex by activating contralateral muscles
crossed extensor
The ______ of each spinal nerve innervates the skin and muscles of the back
dorsal ramus
The tough, fibrous outermost covering of the spinal cord is
dura mater
The subdural space lies between
dura mater and arachnoid mater
The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the
endoneurium
The outermost connective-tissue covering of nerves is the
epineurium
The outward projections from the central gray matter of the spinal cord are called
horns
Enlargements of the spinal cord occur
in those spinal segments that control the limbs
In meningitis
inflammation of the meninges of the brain and spinal cord
Reflexes based on synapses formed during development are ________ reflexes.
innate
Blood vessels that supply the spinal cord run along the surface of the
pia material
The complex interwoven network formed by contributions from the ventral rami of neighboring spinal nerves is termed a(n)
plexus
In which of the following would the delay between stimulus and response be greater
polysynaptic reflex
If the dorsal root of a spinal nerve is severed,
sensory input would be blocked
The posterior horns of the spinal cord contain mainly
sensory nuclei
Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the
subarachnoid space
cerebrospinal fluid flows within the
subarachnoid space
The stretch reflex
the contraction of a muscle in response to stretch of that muscle
The flexor reflex
the quick contraction of flexor muscles resulting in the withdrawal of a limb from an injurious stimulus
Reflexes can be classified according to all of the following, except
whether they are sensory or motor
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
Identify the structure labeled "10"
anterior gray commissure
Nerve tracts or fasciculi make up the
anterior white columns
The dorsal root of a spinal nerve contains
axons of sensory neurons
The layer of the meninges in direct contact with the spinal cord is the
pia mater
After age ________ the vertebral column continues to elongate, but the spinal cord itself does not.
4
In which structure are sensory cell bodies located
10
Which of the following associations is incorrect
11 thoracic spinal nerves
Where do somatic motor neurons reside
15
The spinal cord consists of five regions and ______ segments
31
The _______ is a strand of fibrous tissue that provides longitudinal support as a component
Filum terminale
In an adult, the conus medullaris is found at about
L1
Tina falls while climbing a tree and lands on her back. Her frightened parents take her to the emergency room, where she is examined. Her knee-jerk reflex is normal and she exhibits a plantar reflex (negative Babinski reflex). These results suggest that
Tina suffered no damage to her spinal cord.
Identify the structure labeled "6"
White ramus
The obturator nerve is distributed to the
adductors of the hip
All of the following are true of polysynaptic reflexes except that they
are arranged according to dermatomes
All of the following are true of muscle spindles except that they
are found in tendons
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
Postganglionic fibers of the autonomic nervous system that innervate internal organs do not rejoin the spinal nerve but form
autonomic nerves
The ventral root of a spinal nerve contains
axons of motor neurons
Spinal nerves are
both sensory and motor
In which plexus does the ulnar nerve arise?
brachial
The ventral rami of spinal nerves c5 to t1 contribute fibers to the ______ plexus
brachial
All of the following are true of neural reflexes except that they
cannot be modified by the brain
Which of the following is not true about a positive babinski reflex
causes you to close your eyes when you sneeze
The dorsal root ganglia mainly contain
cell bodies of sensory neurons
Muscles of the neck and shoulder are innervated by spinal nerves from the ________ region.
cervical
In the spinal cord white matter is separated into ascending and descending Tracts organized as
columns
The epidural space contains
connective tissue and blood vessels
The white matter of the spinal cord contains
myelinated and unmyelinated nerve fibers
The reflex that prevents a muscle from exerting too much tension is the ________ reflex.
golgi tendon
Axons crossing from one side of the spinal cord to the other within the gray matter are found in the
gray commissures
the postganglionic fibers that connect an autonomic ganglion in the thoracic or lumbar region with the spinal nerve are
gray rami communicates
The white matter of the spinal cord is mainly
myelinated axons
A viral disease that destroys the cells of the anterior gray horn will
lead to skeletal muscle weakness or paralysis.
Spinal nerves from the sacral region of the cord innervate the ________ muscles.
leg
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
Each peripheral nerve provides ________ innervation to peripheral structures.
motor and sensory
Somatic motor neurons in the spinal cord control all of the following muscles except those that
move the neck
Recognized neuronal circuit patterns include all of the following, except
multipolar
The gray horns of the spinal cord contain mainly
nerve cell bodies
The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the
perineurium
The _______ nerve which arises in the cervical plexus innervates the diaphragm
phrenic
The brachial plexus gives rise to all of the following nerves except the
phrenic
Identify the structure labeled "1"
posterior white column
Identify the structure labeled "5"
rami communicantes
Spinal interneurons inhibit antagonist motor neurons in a process called
reciprocal inhibition
Each of the following nerves originates in the lumbar plexus except the _______ nerve
sciatic
Compared to the vertebral column, the spinal cord is
shorter
The anterior horns of the spinal cord contain mainly
somatic motor nuclei
What is the function of the structure labeled "12"
somatic sensory receiving
The specialized membranes that surround the spinal cord are termed the
spinal meninges
A dorsal and ventral root of each spinal segment unite to form a
spinal nerve
Identify the structure labeled "8"
spinal nerve
Identify the structure labeled "2"
ventral ramus
The _______ innervates the ventrolateral body surface structures in the body wall and the limbs
ventral ramus