Quiz 5: Sidman (Ch 21)

Question 1

On this section drawn in the _____ plane, draw a Betz cell axon as it courses through the white matter.

Answer 1

Betz cell axon: line from left dots to lower middle circles

coronal

Question 2

The medical term “stroke” is commonly used for an acute loss of some neurological function because of blood vessel disease. One manifestation of the stroke resulting from the lesion diagrammed is _____ of voluntary movement of the face, arm, and leg on the _____ side.

Answer 2

paralysis; left

Question 3

When the lesion, as diagrammed, is in the _____ _____, limb reflexes are still present but _____ use of the limb is lost.

Answer 3

internal capsule; voluntary

Question 4

Lesions of corticospinal fibers above the level of the decussation of the pyramids cause paralysis on the _____ side of the body; lesions below the decussation cause paralysis on the _____ side. “Paralysis” is the term meaning inability to _____.

Answer 4

contralateral (opposite); ipsilateral (same); move

Question 5

A lesion in this shaded area leads to paralysis of the arm and leg on the _____ side of the body. In addition, the axons of cranial nerve XII cease to function on the _____ side.

Answer 5

right (contralateral); left (ipsilateral)

Question 6

In all three lesions, there is loss of _____ movement of the left arm and _____. The only lesion that abolishes function in cranial nerve XII as well is the one in the section through the _____.

Answer 6

voluntary; leg; medulla

Question 7

A lesion in the corona radiata that interrupts all corticospinal axons influencing the left arm and leg is much _____ in size than a lesion in the medulla with the same consequences. Shade in the affected area on the section.

Answer 7

larger
Shade in right side of bottom shaded area

Question 8

The lesion (shaded) in the internal capsule affects efferent corticospinal fibers as well as afferent fibers coming to the _____ gyrus from cell bodies in the _____. The resulting loss is in _____ function and in the _____ class of sensory function.

Answer 8

postcentral; thalamus; motor; somesthetic

Question 9

A lesion may produce many effects if different types of axons all pass through the damaged area. On the diagram, shade in the smallest lesion that would concurrently affect voluntary motor, somesthetic sensory, and visual functions.

Answer 9

Shade in inner C of brain and point arrows from both sides to inner C

Question 10

From the combinations of symptoms reported and signs detected by examination, the physician, knowing the kinds of axons that would have to be involved, deduces the anatomical _____ and size of the lesion.

Answer 10

location

Question 11

This patient had a stroke with occlusion of the artery supplying the corona radiata in the central part of his _____ cerebral hemisphere.

Answer 11

right

Question 12

A lesion at “A” lies _____ to the pyramidal decussation and affects voluntary control of the _____ leg. A lesion at “B” affects voluntary control of the _____ leg.

Answer 12

superior; right; left

Question 13

Since the right lower side of the face is paralyzed in a left cortical lesion, many cortico_____ fibers also must cross the midline.

Answer 13

corticonuclear

Question 14

Decussation of corticonuclear fibers is not easily demonstrated in stained sections, even though clinical data make it clear that such decussations must occur. Corticonuclear fibers must cross at many levels in groups of _____ size.

Answer 14

variable

Question 15

If the shaded area were destroyed by sudden occlusion of the artery that nourishes it, the patient would likely be unable to move the lower _____ side of the face or the _____ arm and leg.

Answer 15

right (contralateral); right (contralateral)

Question 16

Much of our knowledge of human neuroanatomy comes from the study of neurological disease. For example, since corticospinal lesions on one side do not paralyze breathing, we conclude that nerve cells that directly innervate intercostal muscles and the diaphragm are influenced by corticospinal fibers of _____ sides of the brain.

Answer 16

both

Question 17

A unilateral lesion affecting corticonuclear fibers commonly has no effect on voluntary chewing, swallowing, or phonating. Also, upper facial muscles that control forehead and brow movement are spared. Presumably, the neuromuscular apparatus directly affecting these motor functions is influenced by corticonuclear fibers of _____ sides. Corticonuclear lesions that do affect these functions must be _____.

Answer 17

both; bilateral

Question 18

The movements characteristically affected in unilateral corticonuclear and corticospinal lesions are movements of the tongue (transiently affected), lower face, arm, and leg on the _____ side from the lesion. Whether or not the anatomist can demonstrate it, most of these fibers must _____.

Answer 18

contralateral; decussate