Mastering A&P Ch. 13 and 16

What is the first step of a reflex?

the arrival of a stimulus and the activation of a receptor

Which of the following is NOT a method by which reflexes can be classified? A. The site from which information is obtained B. The complexity of the neural circuit C. The site where information processing occurs D. The nature of the resulting motor responses

the site from which information is obtained

In the spinal cord, the gray horns contain __________.

visceral and somatic sensory and motor nuclei

What reflex causes the movement of a body part away from a stimulus?

withdrawal reflex

What is the term for the expanded segment of the spinal cord where nerves that serve the shoulder and upper limbs exit?

Cervical enlargment

Jon is learning to drive, and although at first he was slow to step on the brake when trouble appeared, he now does it automatically. What kind of reflex has Jon developed?

acquired

A bilateral region of skin that is innervated by a single pair of spinal nerves is a __________.

dermatome

In what pattern of neural processing does one neuron synapse with several neurons?

divergence

Which of the following spinal cord structures is NOT properly associated with its characteristics? A. Columns -- regions of myelinated axons B. Central canal-- located within grey mater C. Horns-- regions of cell bodies and unmyelinated axons D. Dorsal root-- linked to lateral gray horn

dorsal root—linked to lateral gray horn

Which of these terms about nerves is INCORRECTLY associated with its meaning? A. Dermatome: specific region of the body surface monitored by a spinal nerve B. Endoneurium: surrounds each myelinated axon and its schwann cells C. Fascicle: the bundle containing all the axons of a spinal nerve, but not the epineurium D. Perineurium: contains arteries and veins

fascicle—the bundle containing all the axons of a spinal nerve, but not the epineurium

Accidentally touching a hot burner on a stove elicits a(n) __________ reflex.

flexor

The median nerve of the brachial plexus innervates the __________.

flexor muscles of the forearm

Dermatomes __________. A. Are clinically important because they indicate which spinal nerve may have suffered damage or infection B. Are regions of skin supplied by specific spinal nerves C. Are areas of skin that may have a loss of sensation if the spinal nerves supplying that area have been damaged D. Have all of the listed characteristics

have all of the listed characteristics

Ryan was in a car accident and has suffered injury to the dorsal root of his C7 spinal nerve on his left side. Which structure would he likely have difficulty receiving sensations from after this injury?

his left index finger

Gray matter in the spinal cord is divided into __________.

horns

What term is given to the projections of gray matter toward the outer surface of the spinal cord?

horns

Which type of reflex is genetically or developmentally acquired?

innate reflex

Which of the following reflexes is INCORRECTLY linked with its characteristics? A. innate reflex—produces complex, learned motor pattern B. monosynaptic reflex—has one synapse between sensory neuron and motor neuron C. acquired reflex—produces complex, learned motor pattern D. visceral reflex—manages glands, cardiac muscle, or smooth muscle

innate reflex—produces complex, learned motor pattern

What are all the major nerves included in the Brachial Plexus?

-musculocutaneous nerve -radial nerve -median nerve -ulnar nerve -axillary nerve

There are __________ major plexuses of the spinal nerves.

4

The adult spinal cord is about __________ long

45 cm (18 inches)

What is the fourth step in the activation of a reflex arc?

Activation of a motor neuron

What is the first step in the activation of a reflex arc?

Activation of receptor by a stimulus

What is the second step in the activation of a reflex arc?

Activation of sensory neuron

Which of the following reflexes prevents you from falling when you slip in a puddle of water in your kitchen? A. contralateral B. crossed extensor C. polysynaptic D. All of the listed responses are correct.

All of the listed responses are correct.

Which of the following statements about the peripheral distribution of spinal nerves is INCORRECT? A. The largest branch from a spinal nerve is the ventral ramus. B. All spinal nerves branch to form gray and white rami communicantes. C. White rami communicantes carry information toward the sympathetic ganglia. D.Rami communicantes are nerve branches to and from sympathetic chain ganglia near the spinal cord

All spinal nerves branch to form gray and white rami communicantes.

Monosynaptic reflexes __________

Are the simplest reflexes, have a single synapse, and have the shortest delay.

Which of the following is NOT a reflex found in a normal, healthy adult? A. Stretch Reflex B. Tendon Reflex C. Babinski Reflex D. Plantar Reflex

Babinski reflex

The collection of dorsal and ventral roots that continues through the vertebral canal and resembles a horse's tail is the __________.

Cauda equina

Anatomically, the spinal cord is part of the __________, and the spinal nerves are part of the __________.

CNS; PNS

Which of the spinal meninges is the outermost, dense, collagenous layer?

Dura mater

What is the third step in the activation of a reflex arc?

Information processing in the CNS

The patellar reflex __________.

Is triggered by stretching of the quadriceps muscles, is an example of a monosynaptic reflex and a stretch reflex, and causes a rapid increase and then decline in the muscle tone of the quadriceps

Which of the following statements about the tendon reflex is FALSE? A. It has reverberating circuits that prolong the reflexive motor response. B. It prevents opposing tendon force through reciprocal inhibition. C. It prevents muscles from developing enough tension to damage the tendons. D. All of the listed responses are correct.

It prevents opposing tendon force through reciprocal inhibition.

What is the fifth step in the activation of a reflex arc?

Response by a peripheral effector

Which of the following statements about the spinal cord and spinal meninges is INCORRECT? A. The denticulate ligaments are paired lateral extensions from the pia mater to the dura mater that prevent lateral movement of the spinal cord. B. The spinal meninges provide physical stability, shock absorption, and a pathway for blood vessels for the spinal cord C. The cauda equina refers to the area of the spinal cord just under the pia mater. D. The meninges cover the entire spinal cord and extend over the spinal nerve roots to fuse with tissues covering the spinal nerves.

The cauda equina refers to the area of the spinal cord just under the pia mater.

Which of the following is NOT among the basic characteristics of polysynaptic spinal reflexes? A. The distribution of active neurons is intersegmental. B. The response is always to inhibit muscles. C. Several reflexes may cooperate to produce a coordinated response. D. The response may be inhibitory to some muscles or excitatory to other muscles.

The response is always to inhibit muscles.

Which of the following statements about the spinal cord is FALSE? A. Spinal nerves contain both sensory and motor fibers B. There are 31 pairs of spinal nerves C. The spinal cord itself extends the length of the entire vertebral column D. All of the above are true, none are false

The spinal cord itself extends the length of the entire vertebral column.

Which of the following is/are composed of myelinated fibers carrying information toward the brain A. ascending tracts B. gray commissures C. lateral gray horn D. descending tracs

ascending tracts

What plexus includes the ulnar nerve?

brachial plexus

An epidural block __________.

can be given to control pain during labor

The filum terminale and spinal nerves in the lumbar and sacral regions are called the __________.

cauda equina

The dorsal root ganglion contains the __________ of __________ neurons.

cell bodies; sensory

The space between the arachnoid and pia mater is filled with __________.

cerebrospinal fluid

Regions of the spinal cord are expanded to accommodate sensory and motor information associated with the limbs. These expanded areas are called the __________.

cervical and lumbar enlargements

What plexus includes the phrenic nerve, a nerve that controls the diaphragm?

cervical plexus

In what pattern of neural processing do several neurons synapse on one neuron?

convergence

The reflex that complements a withdrawal reflex, making compensatory adjustments on the side of the body opposite that which receives the stimulus, is the __________ reflex.

crossed extensor

Which of the following reflexes will cause a motor response on the side opposite the stimulus? A. Tendon reflex B. Crossed extensor reflex C. withdrawal reflex D. stretch reflex

crossed extensor reflex

he branches of the ansa cervicalis innervate the __________.

laryngeal muscles

Acquired reflexes are __________.

learned responses

Which of these nerves does NOT arise from the cervical plexus? A. Greater auricular nerve B. Supraclavicular nerve C. Phrenic nerve D. median nerve

median nerve

The membranes surrounding and protecting the brain and spinal cord are the __________.

meninges

What is the term for a reflex where the sensory neuron synapses directly on the motor neuron?

monosynaptic reflex

The connective tissue that wraps bundles of axons into fascicles is the __________.

perineurium

The most important branch of the cervical plexus is the __________ nerve, which innervates the diaphragm.

phrenic

Sherry runs a feather along the sole of her 10-year-old brother's foot. His toes immediately curl in response to the touch. What type of reflex has just occurred?

plantar reflex

Which part of the gray matter in the spinal cord contains somatic and visceral sensory nuclei?

posterior grey horns

Which of the following nerves innervates the sphincter muscles controlling defecation and urination? A. Obturator nerve B. Pudendal nerve C. Saphenous nerve D. Genitofemoral neve

pudendal nerve

What term describes the action of the neural circuit when collateral branches of axons extend back and further stimulate presynaptic neurons?

reverberation

Susan is doing hip extension movements during an exercise class. Which plexus and nerve is she using to contract the gluteus maximus muscle?

sacral plexus and inferior gluteal nerve

Which of these plexuses is INCORRECTLY linked with its contributing nerves? A. Brachial plexus: C5-T1 B. Cervical plexus: C1-C5 C. Lumbar Plexus: T12-L4 D: Sacral Plexus: L5-S4

sacral plexus—L5 through S4

What type of reflex is initiated by increasing the length of a muscle and will cause that muscle to contract?

stretch reflex