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