Lecture Quiz 11: Spinal Cord, Nerves, Reflexes

which branch carries motor neurons to structures on the back of the body trunk

1

in which structure are sensory cell bodies located

10

the spinal cord continues to elongate until about age

4 years

sensory information entering the posterior ramus of the spinal nerve is most likely coming from which part of the body

Exteroreceptors on back

The adult spinal cord typically ends between vertebrae

L1-L2

A herniated disc is causing a patient feeling discomfort and weakness in the tibialis muscle and a possible sensation of pins and needles in the foot. At which level is the herniation exerting its pressure?

L5

spinal nerves are

both sensory and motor

which structure is indicated by the arrow (drg)

dorsal root ganglion

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

dura mater

identify the structure labeled "4" (wr)

white ramus

ascending and descending tracts can be found in which area(s) of the spinal cord

1, 2, 3

An example of the brain affecting spinal reflexes is the replacement of the __________ by the __________.

Babinski sign; plantar reflex

Tom is a football player who gets hit hard from behind along his spine. About a week later, he is diagnosed with bacterial meningitis, an infection of the CSF carried through the bloodstream. Given that the infection was associated with blood, which hypothesis is most likely to have occurred?

The pia matter tore away from the spinal cord, damaging the associated blood vessels, which leaked into the subarachnoid space.

which of the following is not true of polysynaptic reflexes

They involve one muscle group.

which of the following is not true regarding an epidural block

This procedure does not provide sustained anesthesia

In which horn are somatic motor nuclei located?

anterior horn

identify the structure labeled "2" (ar)

anterior ramus

all of the following are true of muscle spindles except they

are found in tendons

which nerve, branching from the posterior cord, is indicated by the arrow

axillary

The anterior root of a spinal nerve contains

axons of motor neurons

The posterior root of a spinal nerve contains

axons of sensory neurons

the anterior rami of spinal nerves C5-T1 contribute fibers to the______plexus

brachial

the axillary, radial, and ulnar nerves branch from which plexus

brachial

The spinal cord is part of the ________ nervous system.

central

which nerve plexus innervates the muscles of the neck and diaphragm

cervical

Enlarged area of the spinal cord from which nerves to the shoulder and upper limbs arise.

cervical enlargement

The dura mater tapers inferiorly to form the ________.

coccygeal ligament

A motor neuron typically receives input from neurons that originate in various areas of the brain. This type of circuit is a

convergent circuit

the_________ reflex is a polysynaptic reflex that involves activating muscles contralateral to the receptor

cross extensor

You have a pair of new sneakers. As you walk along the corridor, your foot catches. Immediately, your body responds and you are able to catch yourself before falling. Which reflex was executed?

crossed extensor reflex

The region of the body surface monitored by a pair of spinal nerves is known as a(n) __________.

dermatome

The specific strip of skin that is innervated by a specific spinal nerve is called a

dermatome

The connective tissue layer that covers Schwann cells is the

endoneurium

which nerve is indicated by the arrow (f)

femoral

the conus medullaris region of the spinal cord is anchored to the coccygeal ligament via a strand of fibrous tissue called

filum terminate

which muscle group is innervated primarily by the median nerve

flexor muscles in the forearm

neuronal pools are described as_______

functional groups of interconnected neurons

a typical spinal nerve has a________ramus communicans consisting of unmyelinated axons that innervate glands and smooth muscles

gray

which of the following is not a difference between gray and white matter

gray matter contains cell bodies of both sensory and motor neurons

identify the structure labeled "3"

gray ramus communicans

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

horns

Reflexes that activate muscles on the same side of the body as the stimulus are called

ipsilateral

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

During the procedure known as a(n) ________, a needle is inserted into the subarachnoid space in the inferior lumbar region.

lumbar puncture

A reflex that involves only a sensory neuron and a motor neuron is a______

monosynaptic reflex

The reflex centers in the spinal cord are responsible for relaying what type of neural messages

motor output over spinal nerves

the flexor reflex

moves a limb away from a painful stimulus

Recognized neuronal circuit patterns include all of the following, except

multipolar

The nerve that innervates the flexor muscles locates in the arm (brachium) is the________. this nerves is a branch of the_____cord

musculocutaneous nerve; lateral

The white matter of the spinal cord is mainly

myelinated axons

masses of gray matter within the central nervous system are

nuclei

You are sitting at a Mexican restaurant waiting for your food. The waiter brings a very hot plate, telling you to be careful about touching it. You touch it anyway, producing a pain sensation in your fingers, a withdrawal of your hand, and an auditory comment of what you are thinking. This scenario represents a ________ neuronal circuit.

parallel processing

The loss of feeling and movement of the legs is termed

paraplegia

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

perineurium

Regional loss of sensory or motor function from nerve trauma or compression is termed

peripheral neuropathy

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

phrenic

the_____nerve, which arises in the cervical plexus, innervates the diaphragm

phrenic

The layer of the meninges in direct contact with the spinal cord is the

pia mater

the cerebospinal fluid (CSF) is confined beteeen the_____ and the______

pia mater; arachnoid mater

A complex, interwoven network of nerves is called a

plexus

in this video, all of the nerves located deep in the wooden probe are derived from the_______cord of the brachial plexus

posterior

the______gray horns contain somatic and the visceral sensory nuclei

posterior

identify the word grouping that is correct

posterior division, axillary nerve, deltoid

identify the structure labeled "4" (pgh)

posterior gray horn

which structure is indicated by the arrow (pgh)

posterior gray horns

Identify the structure labeled "1."

posterior white column

Ginny started using the incline program on the treadmill during her workouts. She noticed that at 5 percent incline she felt the burn in her calf muscles while at -5 percent incline her shins tightened. what type of reflex was triggered by her actions

postural reflex

The condition in which a person loses all feeling and movement of the arms and legs due to spinal cord injury is termed

quadriplegia

Loss of feeling in the thumb and first two fingers is most likely due to a damaged ________ nerve.

radial

In a spinal reflex, information flows from __________ to __________ to __________.

receptor; spinal cord; peripheral effector

Spinal interneurons inhibit antagonist motor neurons in a process called

reciprocal inhibition

The neural "wiring" of a single reflex is called a(n)

reflex arc

Clenching the fists often enhances the knee jerk reflex. This is an example of __________.

reinforcement

If the posterior root of a spinal nerve is severed,

sensory input would be blocked

A reflex arc always includes a(n) __________.

sensory neuron, motor neuron, sensory receptor (all answers are correct)

When building a doghouse, Tom misses the nail and hits his thumb with a hammer instead. The pain sensation is immediate and intense. Which of the following is the pattern of neuronal pool interaction most likely to process that sensation?

serial processing

________ reflexes activate the skeletal muscles

somatic

Ken has a herniated disc which is pinching the structure labeled "10". he is most likely experiencing impairment in which sensory pathway

somatic and visceral sensory

The large anterior gray horns of the spinal cord contain mainly

somatic motor nuclei

which structure is indicated by the arrow (ssn)

somatic sensory nuclei

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the

subarachnoid space

what is the area between the arachnoid mater and the pia mater

subarachnoid space

identify the structure labeled "6" (sr)

sympathetic ganglion

sensory information from visceral organs is carried by the

sympathetic nerve

which of the following is not a way that reflexes are classified

sympathetic/parasympathetic

The nerve fibers that form the M of the brachial plexus are derived from which portions of the plexus

the anterior divisions

damage to which branch of the spinal nerve is likely to have an effect on the muscles of the limbs

the anterior ramus

the subdural space lies between

the dura mater and arachnoid mater

Anesthetics administered into the epidural space are advantageous because __________.

the effect is localized and only sensory

The spinal cord consists of four regions and_________ pairs of spinal nerves

thirty-one

bundles of axons in the central nervous system are known as

tracts

Large bundles of axons from several spinal nerves in the brachial plexus are termed

trunks

damage to which of the following nerve (s) will potentially lead to loss of sensation to the little/pinky finger

ulnar nerve

which structure is indicated by the arrow (vr)

ventral root

A reflex that leads to secretion of saliva is a(n) __________ reflex.

visceral

what type of information is communicated through the anterior root of the spinal cord

visceral motor and somatic motor

what is the function of the structure labeled "12" (vmc)

visceral motor control

when the humerus is broken mid-shaft, injury to the radial nerve can often result. Following healing of the broken bone, what muscular deficits would be apparent if the radio nerve had been injured at the area of the fracture

weakness or loss of extension of the wrist

which of the following is an example of the brain modifying reflex patterns

when someone holds their breath when a person deliberately walks on hot coals when someone keeps postponing emptying a full urinary bladder (All of the listed responses are correct.)

Nerve tracts or fasciculi make up the

white columns