physiology chapter 13

Which branch carries motor neurons to structures on the back of the body trunk? A) 1 B) 2 C) 5 D) 7 E) 11

A) 1

In which horn are somatic motor nuclei located? (Figure 13-5) A) anterior horn B) posterior horn C) lateral horn D) dorsal horn E) central horn

A) anterior horn

The anterior root of a spinal nerve contains A) axons of motor neurons. B) axons of sensory neurons. C) cell bodies of motor neurons. D) cell bodies of sensory neurons. E) interneurons

A) axons of motor neurons

Blood vessels that supply the spinal cord run along the surface of the A) pia mater. B) dura mater. C) epidural space. D) subdural space. E) arachnoid mater.

A) pia mater.

Loss of feeling in the thumb and first two fingers is most likely due to a damaged ________ nerve. A) radial B) musculocutaneous C) ulnar D) median E) axillary

A) radial

The neural ʺwiringʺ of a single reflex is called a(n) A) reflex arc. B) ramus. C) ganglion. D) tract. E) circuit.

A) reflex arc.

Bundles of axons in the central nervous system are known as A) tracts. B) ganglia. C) nuclei. D) horns. E) commissures.

A) tracts.

Ascending and descending tracts can be found in which area(s) of the spinal cord? A) 9 B) 8 C) 11, 12, 13, 14 D) 1, 2, 3 E) 4, 5, 6

D) 1, 2, 3

In which structure are sensory cell bodies located? A) 4 B) 6 C) 5 D) 10 E) 12

D) 10

he adult spinal cord typically ends between vertebrae A) T12-L1. B) S4-S5. C) L5-S1. D) L1-L2. E) S5-Co1.

D) L1-L2.

Which of the following is not true of polysynaptic reflexes? A) They involve pools of interneurons. B) They are intersegmental in distribution. C) They involve reciprocal inhibition. D) They involve one muscle group. E) They have reverberating circuits.

D) They involve one muscle group

The ________ nerve, which arises in the cervical plexus, innervates the diaphragm. A) ansa cervicalis B) lesser occipital C) thoracic D) phrenic E) supraclaviculars

D) phrenic

The layer of the meninges in direct contact with the spinal cord is the A) dura mater. B) subarachnoid space. C) arachnoid mater. D) pia mater. E) choroid plexus.

D) pia mater.

The brachial plexus gives rise to all of the following nerves except the A) radial. B) median. C) ulnar. D) musculocutaneous. E) phrenic.

E) phrenic.

Muscles of the neck and shoulder are innervated by spinal nerves from the ________ region. A) cervical B) thoracic C) lumbar D) sacral E) coccygeal

A) cervical

Enlarged area of the spinal cord from which nerves to the shoulder and upper limbs arise. A) cervical enlargement B) lumbar enlargement C) thoracic region D) conus medullaris E) sacral region

A) cervical enlargement

The dura mater tapers inferiorly to form the A) coccygeal ligament. B) conus medullaris. C) cauda equina. D) subarachnoid space. E) denticulate ligament.

A) coccygeal ligament.

Reflexes that activate muscles on the opposite side of the body as the stimulus are called A) contralateral. B) ipsilateral. C) monosynaptic. D) involuntary. E) polysynaptic.

A) contralateral

In ________, one neuron synapses on several postsynaptic neurons. A) divergence B) reverberation C) serial processing D) parallel processing E) convergence

A) divergence

The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the A) endoneurium. B) perineurium. C) epineurium. D) metaneurium. E) subneurium.

A) endoneurium.

A viral disease that destroys the cells of the anterior gray horn will A) lead to skeletal muscle weakness or paralysis. B) interfere with position sense. C) mainly interfere with crude touch and temperature sense. D) block autonomic regulation. E) affect visceral motor function.

A) lead to skeletal muscle weakness or paralysis

Identify the structure labeled ʺ8.ʺ A) peripheral nerve B) posterior ramus C) spinal nerve D) anterior root E) posterior root

C) spinal nerve

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? A) loss of sensation in his torso B) inability to breathe C) problems with moving his arms D) uncontrollable sweating of his feet E) problems moving his legs

A) loss of sensation in his torso

If a person has a crush injury to the C3-C5 spinal segments, you would expect that he A) might be unable to breathe on his own. B) could walk without difficulty. C) would have full range of motion in all extremities. D) would be in a coma. E) would have difficulty chewing and moving the tongue.

A) might be unable to breathe on his own.

In a(n) ________ reflex, a sensory neuron synapses directly on a motor neuron. A) monosynaptic B) ipsilateral C) commensual D) contralateral E) polysynaptic

A) monosynaptic

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. A) parallel processing B) reverberating C) serial processing D) convergent E) divergent

A) parallel processin

The loss of feeling and movement of the legs is termed A) paraplegia. B) hemiplegia. C) spinal shock. D) quadriplegia. E) spinal transection.

A) paraplegia.

The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the A) perineurium. B) epineurium. C) endoneurium. D) epimysium. E) endosteum.

A) perineurium.

The preganglionic fibers that connect a spinal nerve with an autonomic ganglion in the thoracic and lumbar region of the spinal cord and carries visceral motor fibers that are myelinated form the A) white rami communicantes. B) gray rami communicantes. C) posterior ramus. D) anterior ramus. E) dermatomes.

A) white rami communicantes

What is a reflex arc? What components must be present to qualify?

Answer: A reflex arc is the wiring pattern of neurons that underlie a particular reflex. A reflex arc consists of three elements at the minimum: (1) a sensory receptor and neuron to carry afferent information to the CNS; (2) an excitatory synapse on a motor neuron; (3) the motor neuron to generate an action potential and conduct the impulse to an effector such as a skeletal muscle motor unit.

Sometimes, when it is difficult to initiate a knee-jerk reflex by tapping the patellar tendon, a patient will be asked to voluntarily make a fist. Then the reflex will be easily evoked. What does this illustrate about the relation between voluntary and involuntary reflex movement?

Answer: Descending motor tracts that excite the motor neurons that activate forearm and hand muscles also send excitatory impulses to motor neurons lower down the spinal cord. These EPSPs spatially summate with the excitatory inputs from the muscle spindles to quadriceps motor neurons, bringing the quadriceps neurons to threshold, and thus generate a brisk ʺknee-jerkʺ response.

While playing football, Ramón is tackled hard, and as he tries to get up, he finds that he has difficulty flexing and adducting his left thigh and extending his left leg. Which nerve innervating the lower limb may be damaged, and how would the damage affect sensory perception in Ramónʹs left leg?

Answer: Ramón has a damaged left femoral nerve. This nerve also supplies sensory innervation to the skin on the anteromedial surface of the thigh and medial surfaces of the leg and foot, so he will also experience numbness in those regions.

The varicella-zoster virus causes chickenpox and shingles. The virus attacks the dorsal roots of spinal nerves and sensory ganglia of cranial nerves. What are the characteristic symptoms of shingles and where are they localized on the body?

Answer: The symptoms include red skin that is warm to the touch. The skin is extremely sensitive and very painful. Additionally, the skin forms painful blisters that are slow to heal. The rash follows the dermatome of the affected sensory nerve so it is typically a small area and usually affects only on one side of the body.

Which of the following associations is incorrect? A) 8 cervical spinal nerves B) 11 thoracic spinal nerves C) 5 lumbar spinal nerves D) 5 sacral spinal nerves E) 1 coccygeal spinal nerve

B) 11 thoracic spinal nerves

Damage to which structure would lead to paralysis of limbs? A) 11 B) 2 C) 1 D) 7 E) 9

B) 2

Place the following events of a reflex arc in the correct order: 1) motor neuron activation, 2) sensory neuron activation, 3) sensory receptor activation, 4) Information processing, 5) effector response. A) 3, 2, 1, 5, 4 B) 3, 2, 4, 1, 5 C) 2, 3, 4, 5, 1 D) 4, 3, 1, 2, 5 E) 1, 5, 3, 2, 4

B) 3, 2, 4, 1, 5

Which of the following is not true regarding an epidural block? A) It is commonly used as a method of pain control during labor and delivery. B) This procedure does not provide sustained anesthesia. C) It can provide sensory and motor anesthesia, depending on the anesthetic selected. D) Intubation is not necessary because respiratory muscles are not paralyzed. E) It affects only the spinal nerves in the immediate area of the injection.

B) This procedure does not provide sustained anesthesia.

Nerve plexuses are formed by interconnecting branches of the A) posterior rami. B) anterior rami. C) posterior root. D) anterior root. E) white rami communicans.

B) anterior rami

The posterior root of a spinal nerve contains A) axons of motor neurons. B) axons of sensory neurons. C) cell bodies of motor neurons. D) cell bodies of sensory neurons. E) interneurons.

B) axons of sensory neurons.

The anterior rami of spinal nerves C5 to T1 contribute fibers to the ________ plexus. A) cervical B) brachial C) lumbar D) sacral E) thoracic

B) brachial

The axillary, radial, and ulnar nerves branch from which plexus? (Figure 13-9) A) cervical B) brachial C) lumbar D) sacral E) thoracic

B) brachial

A motor neuron typically receives input from neurons that originate in various areas of the brain. This type of circuit is a A) divergent circuit. B) convergent circuit. C) serial processing circuit. D) parallel processing circuit. E) reverberating circuit.

B) convergent circuit

The conus medullaris anchors the spinal cord to the coccygeal ligament via a strand of fibrous tissue called the A) denticulate ligament. B) filum terminale. C) spinal ligament. D) meningeal ligament. E) dura mater.

B) filum terminale

The large anterior gray horns of the spinal cord contain mainly A) somatic sensory nuclei. B) somatic motor nuclei. C) visceral motor nuclei. D) visceral sensory nuclei. E) sympathetic nuclei.

B) somatic motor nuclei.

The postganglionic fibers that innervate glands in the body wall or smooth muscles in limbs are A) white rami communicantes. B) gray rami communicantes. C) posterior ramus. D) anterior ramus. E) dermatomes.

B) gray rami communicantes.

Identify the structure labeled ʺ3.ʺ A) spinal nerve B) gray ramus communicans C) white ramus communicans D) posterior ramus communicans E) anterior ramus communicans

B) gray ramus communicans

The outward projections from the central gray matter of the spinal cord, seen easily in microscopic spinal cord cross sections, are called A) wings. B) horns. C) pyramids. D) fibers. E) tracts

B) horns.

Reflexes based on synapses formed during development are ________ reflexes. A) visceral B) innate C) acquired D) somatic E) intersegmental

B) innate

Reflexes that activate muscles on the same side of the body as the stimulus are called A) contralateral. B) ipsilateral. C) monosynaptic. D) involuntary. E) polysynaptic.

B) ipsilateral.

Each of the following nerves originates in the lumbar plexus except the ________ nerve. A) saphenous B) sciatic C) femoral D) obturator E) genitofemoral

B) sciatic

What is the function of the structure labeled ʺ11ʺ? A) somatic motor control B) somatic sensory receiving C) visceral sensory receiving D) visceral motor control E) ascending pathway

B) somatic sensory receiving

Cerebrospinal fluid flows within the A) filum terminale. B) subarachnoid space. C) dura mater. D) pia mater. E) arachnoid mater

B) subarachnoid space.

Identify the structure labeled ʺ6.ʺ A) autonomic nerve B) sympathetic ganglion C) posterior root ganglion D) rami communicantes E) anterior root

B) sympathetic ganglion

Sensory information from visceral organs is carried by the A) parasympathetic nerve. B) sympathetic nerve. C) anterior ramus. D) posterior ramus. E) rami communicantes.

B) sympathetic nerve.

The reflex that prevents a muscle from exerting too much tension is the ________ reflex. A) stretch B) tendon C) flexor D) crossed extensor E) reciprocal

B) tendon

What is the function of the structure labeled ʺ12ʺ? A) somatic motor control B) visceral motor control C) somatic sensory input D) visceral sensory input E) sensory receptor for pain

B) visceral motor control

The spinal cord continues to elongate until about age A) 20 years. B) 10 years. C) 4 years. D) 6 months. E) 2 months

C) 4 years.

In an adult, the conus medullaris is found at about A) T6. B) T10. C) L1. D) L5. E) C8.

C) L1.

Which of the following is not a reason a reflex response may fail during a clinical exam? A) The person may consciously suppress the response. B) The nerves may be damaged. C) The person may be elderly and no longer have any reflexes. D) The CNS may be damaged. E) There may be nerve conduction problems

C) The person may be elderly and no longer have any reflexes.

All of the following are true of muscle spindles except they A) are found within skeletal muscle. B) consist of specialized fibers called intrafusal fibers. C) are found in tendons. D) are the receptor for the stretch reflex. E) are innervated by gamma motor neurons.

C) 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? A) the anterior gray horns B) the anterior gray commissures C) ascending tracts D) descending tracts E) the anterior white commissures

C) ascending tracts

Spinal nerves are A) purely sensory. B) purely motor. C) both sensory and motor. D) interneuronal. E) involuntary.

C) both sensory and motor

In which plexus does the ulnar nerve arise? A) cranial B) cervical C) brachial D) lumbar E) sacral

C) brachial

The spinal cord is part of the ________ nervous system. A) peripheral B) somatic C) central D) autonomic E) afferent

C) central

In the spinal cord, white matter is separated into ascending and descending tracts organized as A) nuclei. B) ganglia. C) columns. D) nerves. E) horns.

C) columns.

The tough, fibrous, outermost covering of the spinal cord is the A) arachnoid mater. B) pia mater. C) dura mater. D) coccygeal ligament. E) periosteum.

C) dura mater

The most complicated spinal reflexes are called A) collateral reflex arcs. B) ipsilateral reflex arcs. C) intersegmental reflex arcs. D) dermatomes. E) spinal plexuses

C) intersegmental reflex arcs.

The flexor reflex A) prevents a muscle from overstretching. B) prevents a muscle from generating damaging tension. C) moves a limb away from a painful stimulus. D) usually depends on cranial neurons. E) is an example of a monosynaptic reflex.

C) moves a limb away from a painful stimulus.

Recognized neuronal circuit patterns include all of the following except A) convergent. B) divergent. C) multipolar. D) reverberating. E) parallel processing.

C) multipolar.

Masses of gray matter within the central nervous system are A) ganglia. B) columns. C) nuclei. D) commissures. E) horns.

C) nuclei.

Regional loss of sensory or motor function from nerve trauma or compression is termed A) shingles. B) dermatome. C) peripheral neuropathy. D) hemisection. E) areflexia.

C) peripheral neuropathy.

A complex, interwoven network of nerves is called a A) dermatome. B) ramus. C) plexus. D ) ganglion. E) tract.

C) plexus

In the condition ________, a virus infects posterior root ganglia, causing a painful rash whose distribution corresponds to that of the affected sensory nerves as seen in their dermatomes. A) myasthenia gravis B) neuronal damage C) shingles D) chickenpox E) Hodgkinʹs disease

C) shingles

Ken has a herniated disc which is pinching the structure labeled ʺ10ʺ. He is most likely experiencing impairment in which sensory pathway? A) somatic sensory B) visceral sensory C) somatic and visceral sensory D) somatic and visceral motor E) visceral motor

C) somatic and visceral sensory

The specialized membranes that surround the spinal cord are termed the A) cranial meninges. B) cranial mater. C) spinal meninges. D) spinal mater. E) epidural membranes.

C) spinal meninges.

A posterior and anterior root of each spinal segment unite to form a A) cervical enlargement. B) lumbar enlargement. C) spinal nerve. D) denticulate ligament. E) spinal ganglion.

C) spinal nerve.

What is the area between the arachnoid mater and the pia mater? (Figure 13-3) A) dura mater B) subdural space C) subarachnoid space D) denticulate space E) epidural space

C) subarachnoid space

Which of the following is not a way that reflexes are classified? A) innate/acquired B) somatic/visceral C) sympathetic/parasympathetic D) monosynaptic/polysynaptic E) spinal/cranial

C) sympathetic/parasympathetic

The subdural space lies between A) the arachnoid mater and the pia mater. B) the pia mater and the dura mater. C) the dura mater and the arachnoid mater. D) the pia mater and the subarachnoid space. E) the endosteum and the periosteum.

C) the dura mater and the arachnoid mater.

Identify the structure labeled ʺ4.ʺ A) spinal nerve B) gray ramus C) white ramus D) posterior ramus E) anterior ramus

C) white ramus

Suppose that you feel something brushing against your abdomen. The sensory information would be carried to the spinal cord over a(n) ________ ramus. A) posterior B) sympathetic C) lateral D) anterior E) ascending

D) anterior

Identify the structure labeled ʺ9.ʺ A) anterior white commissure B) anterior median fissure C) anterior white column D) anterior gray commissure E) anterior white horn

D) anterior gray commissure

The ________ innervates the ventrolateral body surface, structures in the body wall, and the limbs. A) white rami communicantes B) gray rami communicantes C) posterior rami D) anterior rami E) dermatomes

D) anterior rami

Identify the structure labeled ʺ2.ʺ A) anterior root B) posterior ramus C) spinal nerve D) anterior ramus E) white ramus

D) anterior ramus

All of the following are true of neural reflexes except that they A) are automatic motor responses. B) are the simplest form of behavior. C) help preserve homeostasis. D) cannot be modified by the brain. E) involve at least two neurons.

D) cannot be modified by the brain.

The posterior root ganglia mainly contain A) axons of motor neurons. B) axons of sensory neurons. C) cell bodies of motor neurons. D) cell bodies of sensory neurons. E) synapses

D) cell bodies of sensory neurons.

Which of the following is not true about a positive Babinski reflex? A) normal in newborns B) abnormal in adults C) a sign of injury to descending spinal tracts D) clinicians test this when a peripheral nerve injury is suspected E) flaring of the toes when the sole is stroked

D) clinicians test this when a peripheral nerve injury is suspected

The ________ reflex complements the flexor reflex by activating contralateral muscles. A) stretch B) tendon C) flexor D) crossed extensor E) reciprocal

D) crossed extensor

These structures extending from the pia mater through to the dura mater support the spinal cord by preventing lateral movement. A) coccygeal ligament B) rami communicantes C) cauda equina D) denticulate ligaments E) spinal ligaments

D) denticulate ligaments

What are the four ways reflexes can be classified? (Figure 13-15) A) monosynaptic, polysynaptic, monosegmental, polysegmental B) flexor, extensor, crossed extensor, withdrawal C) somatic, muscle, visceral, autonomic D) development, response, complexity, processing site E) dorsal, ventral, lateral, central

D) development, response, complexity, processing site

The outermost connective tissue covering of nerves is the A) endoneurium. B) endomysium. C) perineurium. D) epineurium. E) epimysium.

D) epineurium.

Axons crossing from one side of the spinal cord to the other within the gray matter are found in the A) anterior gray horns. B) lateral gray horns. C) posterior gray horns. D) gray commissures. E) white commissures.

D) gray commissures

Spinal nerves from the sacral region of the cord innervate the ________ muscles. A) shoulder B) intercostal C) abdominal D) leg E) facial

D) leg

During the procedure known as a(n) ________, a needle is inserted into the subarachnoid space in the inferior lumbar region. A) myelography B) encephalomyelogram C) laminectomy D) lumbar puncture E) thoracic tap

D) lumbar puncture

The white matter of the spinal cord is mainly A) unmyelinated axons. B) neuroglia. C) Schwann cells. D) myelinated axons. E) nodes of Ranvier.

D) myelinated axons.

The gray horns of the spinal cord contain mainly A) nerve tracts. B) columns. C) meninges. D) neuron cell bodies. E) funiculi

D) neuron cell bodies.

Identify the structure labeled ʺ4.ʺ A) posterior gray column B) posterior gray ganglion C) posterior white column D) posterior gray horn E) anterior gray horn

D) posterior gray horn

The condition in which a person loses all feeling and movement of the arms and legs due to spinal cord injury is termed A) paraplegia. B) hemiplegia. C) spinal shock. D) quadriplegia. E) spinal transection

D) quadriplegia.

Spinal interneurons inhibit antagonist motor neurons in a process called A) a crossed extensor reflex. B) a stretch reflex. C) a tendon reflex. D) reciprocal inhibition. E) reverberating circuits

D) reciprocal inhibition.

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the A) dura mater. B) arachnoid mater. C) epidural space. D) subarachnoid space. E) cerebral ventricles.

D) subarachnoid space

The spinal cord consists of four regions and ________ pairs of spinal nerves. A) five B) twelve C) twenty-five D) thirty-one E) The number varies widely among individuals

D) thirty-one

Large bundles of axons from several spinal nerves in the brachial plexus are termed A) cords. B) rami. C) dermatomes. D) trunks. E) roots.

D) trunks.

Nerve tracts or fasciculi make up the A) central canal. B) posterior gray horns. C) gray commissures. D) white columns. E) anterior gray horns.

D) white columns.

Where do somatic motor neurons reside? A) 9 B) 11 C) 12 D) 13 E) 14

E) 14

Which of the following is not true of meningitis? A) Inflammation of the meninges occurs. B) Bacteria can be the cause. C) Viruses can be the cause. D) CSF flow can be disrupted. E) It only affects spinal meninges.

E) It only affects spinal meninges.

________ reflexes activate skeletal muscles. A) Involuntary B) Cranial C) Spinal D) Autonomic E) Somatic

E) Somatic

Axons cross from one side of the spinal cord to the other through the A) lateral white column. B) posterior gray horn. C) central canal. D) posterior median sulcus. E) anterior white commissure.

E) anterior white commissure.

The specific strip of skin that is innervated by a specific spinal nerve is called a A) root. B) ramus. C) trunk. D) ganglion. E) dermatome.

E) dermatome

Arrange the spinal meninges from innermost layer to outermost layer. A) dura mater, arachnoid mater, pia mater B) dura mater, pia mater, arachnoid mater C) arachnoid mater, pia mater, dura mater D) pia mater, dura mater, arachnoid mater E) pia mater, arachnoid mater, dura mater

E) pia mater, arachnoid mater, dura mater

The complex, interwoven network formed by contributions from the anterior rami of neighboring spinal nerves is termed a(n) A) dermatome. B) autonomic nerve. C) lateral nerve. D) tract. E) plexus.

E) plexus.

A(n) ________ reflex has at least one interneuron placed between the sensory and motor neurons. A) monosynaptic B) ipsilateral C) contralateral D) involuntary E) polysynaptic

E) polysynaptic

Identify the structure labeled ʺ1.ʺ A) anterior white column B) lateral white column C) lateral white horn D) median commissure E) posterior white column

E) posterior white column

The largest peripheral nerve is the ________ nerve. A) median B) femoral C) phrenic D) obturator E) sciatic

E) sciatic

If the posterior root of a spinal nerve is severed, A) output to skeletal muscles would be blocked. B) output to visceral organs would be blocked. C) efferent fibers would be blocked. D) the brain would not be able to communicate with that level of the spinal cord. E) sensory input would be blocked.

E) sensory input would be blocked.

Preganglionic and postganglionic fibers of the autonomic nervous system that innervate internal organs are collectively called A) posterior rami. B) anterior rami. C) white rami. D) gray rami. E) sympathetic nerves.

E) sympathetic nerves.