A&P Test 4

When a person is exposed to temperature extremes, why is it difficult to distinguish hot from cold objects?

At extremes, pain receptors are stimulated by both very hot and very cold objects.

Why isn't an action potential transmitted from a postsynaptic membrane to a presynaptic terminal?

Presynaptic terminals have no acetylcholine receptors.

When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to sodium ions,

an excitatory postsynaptic potential (EPSP) will result

During an autopsy the brainstem was separated from the rest of the brain by a cut between the

midbrain and diencephalon

The perineurium

bundles axons into fascicles

What is the large C-shaped mass of white matter that consists of nerve fibers that connect the two cerebral hemispheres?

corpus callosum

The gray matter on the outer surface of the cerebrum is called the

cortex.

The central sulcus separates the

frontal and parietal lobes.

Which portion of the brainstem is continuous with the spinal cord?

medulla oblongata

A patient with a traumatic head injury may exhibit vomiting as a result of irritation of nuclei in the

medulla oblongata.

The endoneurium

surrounds individual axons and their Schwann cells

The lateral fissure separates the _____ from the rest of the cerebrum.

temporal lobe

Most sensory input that ascends through the spinal cord and brainstem projects to the

thalamus

The interthalamic adhesion connects the two portions of the

thalamus

The primary somatic sensory or general sensory area is located in

the postcentral gyrus

Chemical synapses are characterized by

the release of neurotransmitter by the presynaptic terminal.

The superior and inferior colliculi are located in which of the following portions of the midbrain?

tectum (roof)

The inferior colliculi

are involved with auditory pathways in the CNS.

Which of the following result when the spinal cord is hemitransected (cut) on the left side? (1) loss of pain and thermal sensations below the injury on the left side (2) loss of pain and thermal sensations below the injury on the right side (3) loss of fine touch and pressure sensations below the injury on the left side (4) loss of fine touch and pressure sensations below the injury on right side (5) loss of fine motor control on the right side below the injury (6) loss of fine motor control on the left side below the injury

1, 2, 3, 6

Indicate the order of each of the following in a descending pathway. (1) cerebral cortex (2) pyramids (3) cerebral peduncles (4) internal capsule

1, 4, 3, 2

Arrange the following in order from the diencephalon downward. (1) spinal cord (2) midbrain (3) medulla (4) pons

2, 4, 3, 1

Arrange the events of synaptic transmission in correct sequence. (1) sodium ions diffuse into the cell and cause a local potential (2) neurotransmitter binds with receptor on postsynaptic cell (3) neurotransmitter diffuses across the synaptic cleft (4) membrane permeability to sodium ions on postsynaptic cell increases (5) action potential causes release of neurotransmitter

5, 3, 2, 4, 1

Place the following parts of a reflex arc in the correct order beginning with the sensory receptor. (1) motor neuron (2) interneuron (3) effector (4) sensory neuron (5) sensory receptor

5, 4, 2, 1, 3

Various areas of the cortex form functional pathways to conduct action potentials necessary to perform specific functions. Arrange the areas below in proper sequence to accomplish reading a poem aloud. (1) visual association area (2) premotor area (3) Broca area (4) primary motor area (5) Wernicke area (6) visual cortex

6, 1, 5, 3, 2, 4

Which of the following functions is most likely to be performed by the visual association area? A. "recognizes" the face of a close friend B. "sees" the shape of the visual image C. "senses" pain impulses D. "moves" the eyes E. "sees" color

A

Which of the following is not a lobe of the cerebrum? A. sphenoidal B. frontal C. temporal D. parietal E. occipital

A

Which of the following terms does NOT belong with the others? A. thalamus B. midbrain C. reticular formation D. pons E. medulla oblongata

A

If a person decided to jump over a chair, which of the following areas organizes the motor functions needed to carry out this action. A. prefrontal area B. premotor area C. visual association area D. visual cortex E. auditory association area

B

Which of the following is false? A. The pineal body may play a role in controlling the onset of puberty. B. The thalamus controls many endocrine functions. C. The thalamus projects sensory information to the cerebral cortex. D. The subthalamic nuclei are associated with the basal nuclei. E. The third ventricle separates the two large portions of the thalamus.

B

Which of the following statements concerning the brainstem is true? A. All twelve cranial nerves enter or exit from the brainstem. B. Damage to the brainstem is usually fatal. C. The brainstem consists of the medulla, pons, and cerebellum. D. The brainstem is a relay for sensory input. E. The brainstem is responsible for higher level thinking skills.

B

Which of the following would you observe in a patient with a tumor of the cerebellum? A. loss of general sensation B. balance impairment C. no heartbeat D. no conscious thought E. great sex drive

B

Which of the following is correctly associated with the medulla oblongata? A. It is the most superior portion of the brainstem. B. It contains enlargements called cerebral peduncles. C. It contains nuclei for regulation of heart rate and blood vessel diameter. D. It gives rise to conscious thoughts. E. It relays sensory information.

C

Which of the following pairs is mismatched? A. adaptation - decreased sensitivity to continued stimulus B. proprioceptors - information about body position C. cutaneous receptors - associated with the viscera D. projection - sensation is perceived at the site of the stimulus E. visceroreceptors - associated with organs

C

Which of the following statements concerning the descending pathways of the spinal cord is true? A. Most descending pathways control sensory functions. B. Many of the descending pathways decussate in the midbrain. C. Descending pathways consist of upper and lower motor neurons. D. These pathways start in the spinal cord and end in the brain. E. Descending pathways must synapse in the thalamus.

C

Which of the following combinations indicates the correct distribution of spinal nerve pairs? A. 8 cervical - 12 thoracic - 6 lumbar - 4 sacral - 1 coccygeal B. 7 cervical - 12 thoracic - 5 lumbar - 6 sacral - 1 coccygeal C. 7 cervical - 12 thoracic - 6 lumbar - 5 sacral - 1 coccygeal D. 8 cervical - 12 thoracic - 5 lumbar - 5 sacral - 1 coccygeal E. 7 cervical - 13 thoracic - 6 lumbar - 5 sacral - 1 coccygeal

D

Which of the following is a somatic sense? A. sound B. smell C. taste D. touch E. sight

D

Which of the following is an ascending pathway in the spinal cord? A. anterior corticospinal tract B. tectospinal tract C. rubrospinal tract D. lateral spinothalamic tract E. lateral corticospinal tract

D

Which of the following is false? A. The ventral root is formed by the axons of neurons in the lateral and anterior horns. B. The dorsal root of the spinal cord conveys sensory (afferent) nerve impulses to the spinal cord. C. The dorsal and ventral roots unite to form spinal nerves. D. The posterior horn of the cord contains the cell bodies of motor neurons. E. The ventral root of the spinal cord conveys motor (efferent) nerve impulses away from the spinal cord.

D

Which of the following pairs is mismatched? A. left cerebral hemisphere - speech area for most of the population B. left cerebral hemisphere - mathematical hemisphere C. left cerebral hemisphere - analytical hemisphere D. left cerebral hemisphere - spatial perception E. right cerebral hemisphere - recognition of faces

D

Consider the following five terms and determine which does not belong. A. pyramids B. medulla oblongata C. olives D. cardiac center E. pons

E

The sense of taste is an example of a general sense. (T/F)

False

The sensory speech area is Broca area. (T/F)

False

Visceroreceptors are receptors associated with joints, tendons, and other connective tissue. (T/F)

False

The reflex that prevents excessive tension in a muscle is the

Golgi tendon reflex

What is found in the dorsal root ganglion?

The cell bodies of pseudo-unipolar sensory neurons

The ability to detect simultaneous stimulation at two points on the skin is called two-point discrimination. (T/F)

True

The conscious awareness of stimuli received by sensory receptors is called perception. (T/F)

True

The simplest and most common type of sensory nerve endings are free nerve endings. (T/F)

True

Decreased sensitivity to a continued stimulus is called

adaptation.

The white matter of the cerebellum forms a branching network known as the

arbor vitae.

Muscle spindles

are innervated by gamma motor neurons

Association fibers connect

areas of the cerebral cortex within the same hemisphere

Neurotransmitters

cause the production of action potentials in the postsynaptic membrane

The cerebellum communicates with other parts of the CNS by means of nerve tracts called the

cerebellar peduncles

A nurse is caring for a patient who exhibits the following symptoms: (1) inability to maintain balance while walking (2) normal intelligence (3) can initiate voluntary movements although they are somewhat uncoordinated. (4) decreased tone in the skeletal muscles The patient is probably suffering from a condition that affected the

cerebellum.

In the spinal cord, white matter is organized into

columns and the gray matter into horns

Tracts of white matter that connect the right and left hemispheres are composed of

commissural fibers.

The primary motor area

contains a larger area for control of the hand and fingers than for control of the arm and elbow.

The fact that the right side of the brain controls the left side of the body is explained by the

decussation of the pyramids in the medulla

The pyramids of the medulla contain

descending motor tracts

An inhibitory postsynaptic potential (IPSP) can result from the

either influx of chloride or outflow of potassium ions.

The thickest of the meninges is the

dura mater

Monamine oxidase inhibitors (MAO inhibitors)

enhance the breakdown of norepinephrine

The portion of the dorsal column/medial lemniscal tract that carries proprioceptive sensations from nerve endings in the feet and legs is the

fasciculus gracilis.

During brain surgery, the superior portion of the postcentral gyrus of a patient is stimulated. The patient is most likely to

feel pressure on his toes

During brain surgery, the superior portion of the primary somatic sensory cortex of a patient is stimulated. The patient is most likely to

feel something touching his back.

Local hyperpolarization in a synapse is called a(an)

inhibitory postsynaptic potential

The conus medullaris

is a tapered, cone like region immediately inferior to the lumbar enlargement

Rapid removal or destruction of neurotransmitter in the synaptic cleft

may affect the ability of the postsynaptic membrane to generate action potentials

If the ventral root of a spinal nerve were cut, the regions innervated by that spinal nerve would experience complete loss of

movement

A patient has suffered a cerebral hemorrhage that has damaged the primary motor area of his right cerebral cortex. As a result the

patient cannot voluntarily move his left arm or leg.

The part of the brain that connects the medulla to the midbrain is the

pons.

The adaptive significance of the crossed extensor reflex when a person steps on a tack is to

prevent the person from falling down

A decrease in the number of voltage-gated Ca2+ ion channels in the presynaptic terminal would

reduce or inhibit transmission across the synapse

Gamma motor neurons

regulate the sensitivity of the muscle spindle

A bird hits the windshield of your car, and you reflexively duck and close your eyes. Which of the following is responsible for this action?

superior colliculi

The most superficial meningeal layer is

the dura mater.

Slowly adapting proprioceptors that would let you know the position of your thumb without looking at it are known as

tonic receptors.

What is the role of the red nuclei?

unconscious regulation and coordination of motor activities

Cerebrospinal fluid is formed by tissue in the walls and roofs of the

ventricles of the brain

Structurally, the simplest reflex is the

withdrawal reflex