Anatomy Chapter 12

the white matter of the spinal cord contains

bundles of axons that share common origins, destinations, functions

the _______ of each spinal nerve innervates the skin and muscles of the back

dorsal ramus

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

as the _______ nerve approaches the knee, it divides into 2 branches the fibular nerve and the tibial nerve

sciatic

if the dorsal root of a spinal nerves is severed,

sensory input would be blocked

compared to the vertebral column the spinal cord is

shorter

all of the following are true of neural reflexes, except that they

show else variability in response

the ________ nerve, which arises in the cervical plexus, innervates the diaphragm

phrenic

the layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the

endoneurium

enlargements of the spinal cord occur

in segments of the spinal cord that control the limbs

which of the following is not true about a positive Babinski reflex?

why you close your eyes when you sneeze

the tough, fibrous, outermost covering of the spinal cord is the

dura mater

the outward projections from the central gray matter of the spinal cord are called

horns

the complex, interwoven network formed by contributions from the ventral rami of neighboring spinal nerves is termed a

plexus

each of the following nerves originates in the lumbar plexus, except the _________ nerve

sciatic

the posterior horns of the spinal cord contain mainly

sensory nuclei

cerebrospinal fluid flows within the

subarachnoid space

samples of CSP for diagnostic purposes are normally obtained by placing the tip of a needle in the

subarachnoid space

the reflex that prevents a muscle from exerting too much tension is the ______ reflex

tendon

the subdural space lies between

the dura mater and the arachnoid mater

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 automobile ganglion in the thoracic and lumbar region of the spinal cord form the

white rami communicates

in an adult, the conus medullaris is found at about

L1

each peripheral nerve provides ______ innervation to peripheral structures

a or b

the obturator nerve is distributed to the

adductors of the hip

in meningitis,

all

the dorsal root ganglia mainly contain

cell bodies of unipolar neurons

spinal nerves are

mixed nerves (sensory and motor)

recognized neuronal circuit patters include all of the following, except

multipolar

the white matter of the spinal cord is mainly

myelinated axons

the layer of connective tissue that surrounds a fascicle within a peripheral nerve is the

perineurium

which of the following associations is incorrect?

11 thoracic spinal nerves

nerve tracts of fascicle make up the

anterior white columns

all of the following are true of polysnaptic reflexes, except that they

are arranged according to dermatomes

the stretch reflex

both d and b

in which plexus does the ulnar nerve arise?

brachial

the ventral rami of spinal nerves C5 to T1 contribute fibers to the ______ plexus

brachial

the brachial plexus gives rise to all of the following nerves, except the

phernic

the ____________ reflex complements the flexor reflex by activating contralateral muscles

crossed extensor

a dorsal and ventral root of each spinal segment unite to form a

spinal nerve

the outermost connective tissue covering of nerves is the

epineurium

the spinal cord consists of five regions and _____ segments

31

the dorsal root of a spinal nerve contains

axons of sensory neurons

blood vessels that supply the spinal cord run along the surface of the

pia mater

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

the spinal cord continues to elongate until about age

4

axons crossing from one side of the spinal cord to the other within the gray matter are found in the

Gray commissures

in which of the following would the delay between stimulus and response be greater?

a polysnaptic reflex

all of the following are true of muscle spindles, except that they

are found in tendons

mary is in a car accident and suffers a spinal cord injury. Which part of her cord is likely to be compressed?

ascending atracts

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

muscles of the neck and shoulder are innervated by spinal nerves from the _____ region

cervical

the _______ is a stand of fibrous tissue that provides longitudinal support as a component

filum terminale

the postganglionic fivers that connect an autonomic ganglion in the thoracic or lumbar region with the spinal nerve are

gray rami communicates

a viral disease that destroys the cells of the anterior gray horn will

lead to muscle weakness or paralysis

spinal nerves from the sacral region of the cord innervate the _____ muscles

leg

bill contracts a viral disease that destroys the cells in the posterior gray horns in his spinal cord. which of the following would you expect?

loss of sensation in his torso

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 flexor reflex

move limb away from painful stimulus

somatic motor neurons in the spinal cord control all of the following muscles, except those that

move the neck

the gray horns of the spinal cord contain mainly

nerve cell bodies

the ventral rami form four major plexuses, including all of the following, except the ________ plexus

nuchal

spinal interneurons inhibit antagonist motor neurons in a process called

reciprocal inhibition

the anterior horns of the spinal cord contain mainly

somatic motor nuclei

the specialized membranes that surround the spinal cord are termed the

spinal meninges

tina falls while climbing a tree and lands on her back these results suggest that

tina suffered no damage to her spinal cord

the ___________ innervates the ventrolateral body surface, structures in the body wall, and the limbs

ventral ramus