Deck 13: The Peripheral Nervous System and Reflex Activity

Question 1

The musculocutaneous nerve is a major nerve of the brachial plexus.

Answer 1

True

Question 2

Vitamin A needed by the photoreceptor cells is stored by the cells of the retina pigmented layer.

Answer 2

False

Question 3

The neural layer of the retina prevents excessive scattering of light within the eye.

Answer 3

False

Question 4

The fluid contained within the membranous labyrinth is called perilymph.

Question 5

The meningeal branch of a spinal nerve actually reenters the vertebral canal to innervate the meninges and blood vessels.

Question 6

The structure that allows equalization of the pressure in the middle ear with that outside the body is the external auditory meatus.

Question 7

Precision of eye movement is due to the fact that extrinsic eye muscle motor units contain only8 to 12 muscle cells and in some cases as few as 2 or 3 muscle cells.

Question 8

Irritation of the phrenic nerve may cause diaphragm spasms called hiccups.

Question 9

Drooping of the upper eyelid, and double vision are potential symptoms of damage to the oculomotor nerve.

Question 10

Dorsal and ventral rami are similar in that they both contain sensory and motor fibers.

Question 11

Static equilibrium involves the sensation of linear acceleration as well as changes in head rotation.

Question 12

The mucous membrane that lines the eyelids and is reflected over the anterior surface of the eyeball is the conjunctiva.

Question 13

The bending of light rays is called reflection.

Question 14

The optic disc is forms a blind spot where the optic nerve leaves the eyeball.

Question 15

The second cranial nerve forms a chiasma at the base of the brain for partial crossover of neural fibers.

Question 16

Sour taste receptors are stimulated by hydrogen ions of acidic food substances.

Question 17

The anterior chamber of the eye is filled with vitreous humor.

Question 18

Lamellar corpuscles can be exteroceptors, interoceptors, or proprioceptor.

Question 19

Ciliary muscles are considered voluntary, skeletal muscle.

Question 20

Reciprocal inhibition means that while one sensory nerve is stimulated, another sensory neuron for synergistic muscles in the same area is inhibited and cannot respond.

Question 21

Theoretically, an individual born without a middle ear would be able to hear by bone conduction with a hearing aid.

Question 22

We can touch our finger to our nose while our eyes are closed in part because we can sense the position and movement of our joints as well as the length of stretch in our muscles. Thesesensations create awareness of our body's positioning. The following receptors are most likely responsible for this ability.

A) exteroceptors
B) interoceptors
C) proprioceptors
D) nociceptors

Question 23

An emergency medical technician is examining a trauma victim by shining a pen light into her patient's eye. She records the reactivity of the patents pupils as they constrict when stimulated by the light. This test supports which of the following?

A) The patient has lost function of the optic nerve (II).
B) The patient has function of the trochlear nerve (IV).
C) The patient has function of the oculomotor nerve (III).
D) The patient has suffered brain damage.

Question 24

Hair cells in the spiral organ of the ear are never replaced.

Question 25

A bit of dust blows into and touches the cornea of the eye. Which of the following is likely to ha ppen?

A) Nothing, because there is no sensory information sent from the cornea.
B) Stimulation of the facial nerve (VII) will be perceived as pain.
C) Stimulation of the optic nerve (II) will cause tears to flow from the lacrimal gland.
D) Stimulation of the ophthalmic division of the trigeminal nerve (V) will cause blinking.

Question 26

When we move from darkness to bright light, retinal sensitivity is lost, but visual acuity is gained.

Question 27

A patient is suffering from the inability to distinguish various types of odors. This patient may have damage to which of the following?

A) vagus nerve (X)
B) hypoglossal nerve (XII)
C) olfactory nerve (I)
D) facial nerve (VIII)

Question 28

Light passes through the entire thickness of the neural layer of the retina to excite the photoreceptors.

Question 29

A patient has lost vision on the left side of both eyes. The patient has likely suffered damage to________.

A) the optic chiasm
B) the optic nerves
C) the retinas of the eyes
D) the right optic tract

Question 30

Odorants must be volatile to be smelled.

Question 31

A person picks up a heavy suitcase in order to estimate its weight and reflexively drops it.Which of the following receptors has initiated this reflex?

A) bulbous corpuscle
B) tendon organ
C) lamellae corpuscle
D) free nerve ending

Question 32

Which of the following is the best explanation of how a stimulus' strength is transmitted to the central nervous system from sensory nerves?

A) Action potential frequency is increased as stimulus' strength increases.
B) An action potential will increase in strength as stimulus's strength increases.
C) Action potentials as well as graded potentials are sent to the central nervous system when stimulus strength increases.
D) More than one type of receptor will respond to larger stimulus.

Question 33

Without a functioning crista ampullaris, the semicircular canals would not function.

Question 34

In order for sound to reach the spiral organ (of Corti), the auditory ossicles must vibrate the oval window and set the endolymph in motion.

Question 35

Contraction of the ciliary muscle causes the lens to bend the light less.

Question 36

The function of the lens of the eye is to allow precise focusing of light on the retina.

Question 37

Tactile sensation is a combination of touch, pressure, stretch and vibration. Which of the following is most likely the receptor type that senses tactile stimulation?

A) thermoreceptors
B) proprioceptors
C) nociceptors
D) mechanoreceptors

Question 38

If someone spills very hot coffee (200°F) on their skin, they will likely perceive much pain.Which of the following receptor types is causing this sensation?

A) mechanoreceptors
B) nociceptors
C) chemoreceptors
D) thermoreceptors

Question 39

Some large arteries that are proximal to the heart are sensitive to the stretch of the blood vessels. This stretch indicates the blood's pressure. Which of the following pairs ofclassifications below best fit the receptor type that is being described above?

A) thermoreceptors that are also exteroceptors
B) mechanoreceptors that are also exteroceptors
C) thermoreceptors that are also interoceptors
D) mechanoreceptors that are also interoceptors

Question 40

Sound is generally perceived in the occipital lobe of the cerebral cortex.

Question 41

Bill is a mechanic that works with vibrating tools. He also exerts force on his wrists whentwisting wrenches and screws. Bill has a tingling sensation in the lateral portion of his hand. The doctor suspects carpal tunnel syndrome. Which of the following test might the doctor try on her patient?

A) Have bill grip an object with his thumb and index finger and try to pull the object away.
B) Check for reflex on the medial condyle of the humerus with a rubber mallet.
C) Check for hyperextension at the knuckles of the little and ring finger.
D) Have bill flex and extend his arm against resistance.

Question 42

After axonal injury, regeneration in peripheral nerves is guided by _____ ___.

A) Golgi organs
B) Schwann cells
C) Wallerian cells
D) dendrites

Question 43

A doctor asks her patient to follow the motion of her finger as she moves it up and down, left and right. Which of the following cranial nerves is not being tested?

A) the vestibulocochlear nerve (VIII)
B) the oculomotor nerve (III)
C) the trochlear nerve (IV)
D) the abducens (VI)

Question 44

Striking the "funny bone" is actually stimulation of (or injury to) the________.

A) ulnar nerve
B) sciatic nerve
C) median nerve
D) radial nerve

Question 45

As a cook chops red onions he begins to tear up due to activation of the lacrimal gland. Which of the following nerves provided the stimulus?

A) the facial nerve (VII)
B) the olfactory nerve (I)
C) the vagus nerve (X)
D) the optic nerve (II)

Question 46

Starting at the spinal cord, the subdivisions of the brachial plexus are (in order) ________.

A) roots, trunks, divisions, and cords
B) roots, divisions, cords, and trunks
C) trunks, divisions, cords, and roots
D) divisions, roots, trunks, and cords

Question 47

Spinal nerves exiting the cord from the level of L4 to S4 form the ________.

A) lumbar plexus
B) sacral plexus
C) thoracic plexus
D) femoral plexus

Question 48

Injury to cervical vertebra C3-C4 is particularly problematic because ________.

A) several ganglia are near this region that serve the heart
B) part of the brain stem is located here
C) the greater auricular nerve that serve the parotid gland receive there fibers from here
D) the phrenic nerve that serves the diaphragm receives its fibers from here

Question 49

Dermatome maps are useful to clinicians because ________.

A) they show doctors how to avoid striking spinal nerves during surgery
B) they outline the location of the numerous nerve plexus
C) they show the routes of motor nerves
D) they can help pinpoint the location of spinal injury

Question 50

Complicated interlacing of the ventral rami form networks called nerve plexus. Thecrisscrossing of the nerve fibers from the various spinal nerves is advantageous because________.

A) having several nerve fibers unite enhances motor function
B) viruses that infect us by moving through PNS nerves are prevented entry to the CNS
C) having several nerve fibers unite enhances sensory function
D) injury to any single spinal nerve will be less damaging as there is less chance of total loss of innervation to any particular organ

Question 51

In a crossed-extensor reflex, if the right arm was grabbed it would flex and the left arm would________.

A) also flex
B) abduct
C) extend
D) adduct

Question 52

Inborn or intrinsic reflexes are ________.

A) autonomic only
B) always mediated by the brain
C) involuntary, yet may be modified by learned behavior
D) rapid, predictable, and can be learned responses

Question 53

A reflex that causes muscle relaxat ion and lengthening in response to muscle tension is called a________.

A) tendon reflex
B) crossed-extensor reflex
C) flexor reflex
D) plantar reflex

Question 54

A patient has an injury of the spine and is now suffering from a loss of motor function in hisright arm. However, he still has normal sensory function in the arm. Based on this information it is likely that the patient has nervous tissue damage located at ________.

A) the ventral root located at one or more of the cervical vertebra
B) spinal nerves of the cervical vertebra
C) the dorsal rootlets located at one of the thoracic vertebra
D) the dorsal root located at one or more of the cervical vertebra

Question 55

Nerves that carry impulses toward the CNS only are________.

A) mixed nerves
B) afferent nerves
C) motor nerves
D) efferent nerves

Question 56

Which receptors adapt most slowly?

A) pressure receptors
B) nociceptors
C) smell receptors
D) touch receptors

Question 57

The cranial nerve with a cervical origin (spinal cord) is the________.

A) hypoglossal
B) glossopharyngeal
C) vag us
D) accessory

Question 58

Which of the following nerves does not arise from the brachial plexus?

A) median
B) ulnar
C) radial
D) phrenic

Question 59

Regeneration within the CNS ________.

A) is prevented due to growth-inhibiting proteins of oligodendrocytes
B) is more successful than with the PNS
C) is promoted by growth inhibitors and glial scars
D) typical ly allows axonal sprouting of 20 mm

Question 60

The posterior side of the thigh, leg, and foot is served by the ________ nerve.

A) obturator
B) tibial
C) femoral
D) common fibular

Question 61

Bell's palsy is ________.

A) often caused by inflammation of the trigeminal nerve
B) characterized by loss of vision
C) characterized by paralysis of facial muscles
D) characterized by partial paralysis of diaphragm muscles

Question 62

Feeling a gentle caress on your arm would likely involve all of the following except ________.

A) Meissner's corpuscles
B) hair follicle receptors
C) Lamellar corpuscles
D) tactile discs

Question 63

Transduction refers to conversion of ________.

A) stimulus energy into energy of a graded potential
B) receptor energy to stimulus energy
C) presynaptic nerve impulses to postsynaptic nerve impulses
D) afferent impulses to efferent impulses

Question 64

Select the correct definition.

A) Magnitude estimation is the simplest level of sensation.
B) Pattern recognition allows us to see a familiar face.
C) Perceptual detection is the ability to detect how much stimulus is applied to the body.
D) Spatial discrimination allows us to recognize textures.

Question 65

Select the statement that is most correct.

A) Ganglia associated with afferent nerve fibers contain cell bodies of sensory neurons.
B) The cell bodies of afferent ganglia are located in the spinal cord.
C) The dorsal root ganglion is a motor-only structure.
D) Ganglia are collections of neuron cell bodies in the spinal cord that are associated with efferent fibers.

Question 66

The sciatic nerve is a combination of which two nerves?

A) pudendal and common fibular
B) common fibular and tibial
C) posterior femoral cutaneous and tibial
D) pudendal and posterior femoral cutaneous

Question 67

Which of the following is the best explanation for our perception of color?

A) Rods contain a single kind of visual pigment.
B) Cones come in three types, each sensitive to different wavelengths of light.
C) The foveae are densely packed with cones.
D) As many as 100 cones may converge on one ganglion cell.

Question 68

Nutrients are delivered and waste products are carried away from the cells of the posteriorsegment of the eye by blood vessels. However, the cells in the cornea and lens (in the anterior segment) are avascular. Which is the best explanation for how these cells are maintained?

A) These cells, like the cells of the corneal layer of the integument are not living cells.
B) The aqueous humor is continuously replenished and flows from the ciliary process to drain in the scleral venous sinus.
C) The metabolic activity of these cells is very low. They produce little waste and need few nutrients.
D) The nutrients and waste products of the anterior segment diffuse into and through the vitreous humor of the posterior segment.

Question 69

Mixed cranial nerves containing both motor and sensory fibers include all except which of the following?

A) olfactory
B) trigeminal
C) facial
D) oculomotor

Question 70

Which of the following is the best explanation for why night vision is fuzzy and indistinct?

A) Rods contain a single kind of visual pigment.
B) Cones come in three types, each sensitive to different wavelengths of light.
C) The foveae are densely packed with cones.
D) As many as 100 cones may converge on one ganglion cell.

Question 71

Which of the following is the correct simple spinal reflex arc?

A) receptor, afferent neuron, integration center, efferent neuron, effector
B) receptor, efferent neuron, integration center, afferent neuron, effector
C) effector, efferent neuron, integration center, afferent neuron, receptor
D) effector, afferent neuron, integration center, efferent neuron, receptor

Question 72

If the ventral root of a spinal nerve were cut, what would be the result in the tissue or region that nerve supplies?

A) a complete loss of voluntary movement
B) a complete loss of sensation and movement
C) complete loss of sensation
D) loss of neither sensation nor movement but only of autonomic control

Question 73

The flexor muscles in the anterior arm (biceps brachii and brachialis) are innervated by what nerve?

A) ulnar
B) musculocutaneous
C) median
D) radial

Question 74

In a person who is color blind, which of the following would you most expect to see?

A) a loss of functions in the rods of their retina
B) absence of green or red cones in their foveae
C) an inability to regenerate 11-cis-retinal after bleaching
D) a loss of their peripheral vision

Question 75

A fracture of the ethmoid bone could result in damage to which cranial nerve?

A) glossopharyngeal
B) olfactory
C) vag us
D) accessory

Question 76

A fall or an improperly delivered gluteal injection could result in ________.

A) phantom limb pain
B) postpoliomyelitis muscular atrophy
C) neurofibromatosis
D) sciatica

Question 77

Which of the following is the best explanation of why it is difficult to discriminate the color of an object at night?

A) Rods contain a single kind of visual pigment.
B) Cones come in three types, each sensitive to different wavelengths of light.
C) The foveae are densely packed with cones.
D) As many as 100 cones may converge on one ganglion cell.

Question 78

Which nerve is compressed in carpal tunnel syndrome?

A) ulnar
B) radial
C) median
D) axillary

Question 79

All processing at the circuit level going up to the perceptual level must synapse in the________.

A) reticular formation
B) medulla
C) thalamus
D) pons

Question 80

A patient who received a blow to the side of the skull exhibits the following signs andsymptoms on that side of the face: he is unable to close his eye, and the corner of his mouth droops. Which cranial nerve has been damaged?

A) facial
B) hypoglossal
C) glossopharyngeal
D) accessory