A & P Chapter 13

Figure 13-3 Which structure conducts action potentials directly from a sensory receptor?

1

Figure 13-3 Which of the following is true regarding the structure labeled "6"?. 1. The synapse occurs between motor neurons. 2. The sensations may be filtered out. 3. The third-order neuron projects to the primary sensory cortex. 4. The third-order neuron's axon is myelinated by oligodendrocytes

3 and 4

The choroid plexuses produces CSF at a rate of about

500 mL/day.

The adult human brain contains almost ________ of the body's neural tissue.

97 percent

Describe amyotrophic lateral sclerosis (ALS). (Module 13.22C)

ALS is a progressive degeneration of the motor neurons of the CNS, leading to muscle atrophy and eventual paralysis.

The medial and lateral motor pathways can modify, or direct, skeletal muscle contractions by ________ lower motor neurons.

All of the answers are correct.

The cerebellum

All the answers are correct.

Which part(s) of the following statement is/are true?If the primary motor cortex is destroyed, fine control of movement will be lost, but movement may not be lost completely because the medial and lateral pathways can still provide coarse motor control.

Both parts of the statements are true.

Describe the role of the corticobulbar tracts. (Module 13.20A)

Corticobulbar tracts are descending tracts that carry information or commands from the cerebral cortex to motor nuclei in the brainstem.

Define corticospinal tracts. (Module 13.20B)

Corticospinal tracts are descending tracts that carry motor commands from the cerebral cortex to the anterior gray horns of the spinal cord.

What effect would increased stimulation of the motor neurons of the red nucleus have on muscle tone? (Module 13.20C)

It would increase stimulation of skeletal muscles, thereby increasing their muscle tone.

Damage to the substantia nigra causes a decrease in the neurotransmitter dopamine. This causes a gradual, generalized increase in muscle tone, which is the main symptom of

Parkinson's disease.

Damage to the substantia nigra causes a decrease in the neurotransmitter dopamine. This causes a gradual, generalized increase in muscle tone, which is the main symptom of

Parkinsonʹs disease.

Describe how rabies is contracted. (Module 13.22B)

Rabies is contracted by the bite of a rabid animal.

Define referred pain. (Module 13.22A)

Referred pain is a sensation felt in a part of the body other than its actual source.

Which part(s) of the following statement is/are true?Somatic sensory axons enter the ventral root and usually decussate before ascending to thethalamus.

The first part of the statement is false, and the second part of the statement is true.

Describe the role of the medulla oblongata. (Module 13.2A)

The medulla oblongata relays sensory information to other parts of the brainstem and to the thalamus. It also contains centers that regulate autonomic functions, such as heart rate and blood pressure.

________ are chambers within the brain that contain cerebrospinal fluid.

Ventricles

Which of the cranial nerves is named for the fact that it "wanders," that is, innervates structures throughout the thorax and abdomen?

X

Define somatotopy. (Module 13.19A)

a functional map of the somatosensory cortex

Stimulation of a neuron that terminates close to the longitudinal fissure of the left postcentral gyrus would produce

a sensation in the right leg.

The descending spinal tract that crosses to the opposite side of the body within the cord is the ________ tract.

anterior corticospinal

The spinal tract that relays information concerning crude touch and pressure to the CNS is the

anterior spinothalamic tract of the spinothalamic pathway.

The cells that cover the outer surfaces of CNS capillaries cells are the

astrocytes.

The neural tissue is isolated from the general circulation by the

blood-brain barrier.

Which is likely to be more sensitive to continuous deep pressure: a lamellar corpuscle or a bulbous corpuscle? (Module 13.18B)

bulbous corpuscle

The third and fourth ventricles are linked by a slender canal designated as the

cerebral aqueduct.

Figure 13-1 What is produced by the structure labeled "2."?

cerebrospinal fluid

Which of the following is improperly paired?

corpus callosum - thick tract of gray matter that connects the two cerebral hemispheres

A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?

corticobulbar tract

Figure 13-4 What occurs in this neural pathway at label "3"?

decussation

Which of the following lies between the cerebrum and the brainstem?

diencephalon

Which of the following is improperly paired?

diencephalon — becomes the ventricle

As CSF circulates, ________ between it and the interstitial fluid of the CNS is unrestricted between and across the ependymal cells.

diffusion

The dural sinuses are located in the

dural folds.

Which of these is mismatched with its location?

dural venous sinuses; large collecting veins located within the dural folds

Specialized ________ cells form the secretory component of the choroid plexus.

ependymal

Figure 13-2 What is the function of the nerve labeled "10."?

eye movement

The dural fold that projects into the longitudinal fissure between cerebral hemispheres is called the

falx cerebri.

Two large venous sinuses, the sagittal sinuses, lie within a dural fold called the

falx cerebri.

Figure 13-3 Identify the neuron labeled "1."

first-order neuron

The ventricle associated with the pons and upper medulla is the

fourth.

Alzheimer's disease is characterized by all of the following except that it

has a clear genetic basis.

Figure 13-2 What is the function of the nerve labeled "4."?

hearing and balance

A patient develops a tumor of a cranial nerve that leads to difficulty in speaking from a loss of tongue movement. Which cranial nerve is affected?

hypoglossal

The basic reflex motor patterns related to eating and drinking are controlled by which region of the brain? (Module 13.21B)

hypothalamus

The floor of the diencephalon is formed by the

hypothalamus.

Parkinson's disease is the result of

inadequate production of dopamine by substantia nigra neurons.

Each lateral ventricle communicates with the third ventricle through a(n)

interventricular foramen.

Cerebrospinal fluid

is secreted by ependymal cells.

Male brains are typically ________ compared to female brains.

larger

Cerebrospinal fluid enters the subarachnoid space through the

lateral and median apertures.

The descending spinal tract that crosses to the opposite side of the body within the pyramids of the medulla oblongata is the ________ tract.

lateral corticospinal

Which spinal tracts carry action potentials generated by nociceptors? (Module 13.19B)

lateral spinothalamic tracts

Which cerebral hemisphere receives impulses conducted by the right gracile fasciculus? (Module 13.19C)

left cerebral hemisphere

What loss would result from cutting through the medial lemniscus on the right side?

loss of fine touch sensation on the left side of the body

Based on the motor homunculus, which of the following body regions has the largest motor units?

lower limbs

Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.

lower motor

The cerebellum relies on information from all of the following except

lower motor neurons.

Damage to the tectospinal tracts would interfere with one's ability to

make reflex responses of the head and neck in response to sudden movements or loud noises.

Autonomic centers that control blood pressure, heart rate, and digestion are located in the

medulla oblongata.

Figure 13-4 Identify the type of information that travels along the structure labeled "4."

motor commands to skeletal muscles

Damage to the ________ nerve would result in near paralysis of the eye.

oculomotor

Droopy eyelids and double vision can result from injury to the ________ nerve.

oculomotor

Olfactory receptors send axons through the cribriform plate and synapse on neurons in the

olfactory bulb.

Figure 13-3 Identify the type of information that travels along the structure labeled "2."

pain and crude touch sensations

What structure is covered by many blood vessels and adheres tightly to the surface of the brain?

pia mater

The layer of the meninges that closely follows every gyrus and sulcus is the

pia mater.

The tracts that connect the cerebellum to the brainstem are located in the

pons

Upper motor neuron cell bodies originate in all the following except

postcentral gyrus.

Figure 13-4 Identify the structure labeled "1."

primary motor cortex

Which of the following is not one of the main divisions of the adult brain?

prosencephalon

Which structures form the secondary brain vesicles? (Module 13.1B)

prosencephalon and rhombencephalon

Name the three primary brain vesicles. (Module 13.1A)

prosencephalon, mesencephalon, rhombencephalon

Which of the following is not a function of cerebrospinal fluid?

provides ATP for impulse transmission

Your uncle was just diagnosed with a heart attack. One of his major symptoms is left arm pain. You are not surprised because you are familiar with the phenomenon of ________ pain.

referred

Complex motor activities such as riding a bicycle

require the coordinated activity of several regions of the brain.

The spinal tract that normally plays a minor role in the control of the distal muscles of the arms is the ________ tract.

rubrospinal

Increased production and release of acetylcholine by the neurons of the cerebral nuclei would result in

spastic, uncontrolled muscle contractions.

Conscious and subconscious motor commands control skeletal muscles by traveling over all of the following except the

spinothalamic pathway.

What contains a spider web-like network of cells and fibers through which cerebrospinal fluid flows?

subarachnoid space

The tectum of the midbrain contains the

superior and inferior colliculi.?

Cerebrospinal fluid enters the blood circulation at the

superior sagittal sinus.

Which types of tactile receptors are located only in the dermis? (Module 13.18A)

tactile corpuscles, lamellar corpuscles, and bulbous corpuscles

During embryonic development, which of the following secondary brain vesicles will form the cerebrum?

telencephalon

Which embryonic brain vesicle develops into the largest region of the adult brain? (Module 13.1C)

telencephalon

Which brain regions control reflexes in response to visual and auditory stimuli that are experienced while viewing a movie? (Module 13.21A)

thalamus and midbrain

Sensory information is processed and relayed to the cerebrum by the

thalamus.

All of the following help(s) to directly protect the brain except

the neural tubes.

Sensory encoding of the perceived location of a stimulus depends on

the specific location of the cortical neuron that is stimulated.

Figure 13-2 Identify the nerve labeled "11."

trigeminal

Sensory information that arrives at the CNS is routed according to the ________ of the stimulus.

type and location

Figure 13-4 Identify the origin of the axon labeled "2."

upper motor neuron

Absorption at the arachnoid granulations returns CSF to the

venous circulation.

Figure 13-3 Identify the structure labeled "5."

ventral root

The spinal tract that unconsciously maintains balance and muscle tone of the neck, eyes, head, and limbs is the ________ tract.

vestibulospinal

Figure 13-2 What is the function of the verve labeled "5."?

visceral sensation and motor control

Damage to the pyramidal cells of the cerebral cortex would directly affect

voluntary motor activity.

Which of the following symptoms would you associate with damage to the spinal accessory nerve?

weakness of the sternocleidomastoid muscle