Quiz 4: Sidman (Ch 18 & 20)

Question 1

Before it enters the pons, the corticospinal tract transverse the _____ _____ of the midbrain.

Answer 1

basis pedunculi

Question 2

In the coronal section, the corticospinal fibers in the internal capsule are cut lengthwise (longitudinally); in a section transverse to the midbrain, the same fibers are cut in _____ section.

Answer 2

transverse (or cross)

Question 3

The pons appears rounded and bulging on its _____ side.

Answer 3

anterior

Question 4

Note the fourth ventricle (IV) in the transverse section through the pons. The section is at the level marked _____ on the left hand diagram.

Answer 4

B

Question 5

Label the pons (P) and medulla (M). A distinctive structural feature of the pons is the pattern made by the interlacing bundles of white matTer fibers in its anterior, bulging part, The arrow lies along fibers running to the cerebellum. Most of the other fibers are heading for the medulla and belongs to the _____ tract.

Answer 5

Pons: Bottom middle
Medulla: Right side

corticospinal

Question 6

Draw lines to bundles of corticospinal fibers and label them “CS”
Draw arrows on the laterally placed masses of white matter to indicate the direction of impulse conduction in them.

Answer 6

Label “CS” as bottom inner two circles
Draw arrows on outer sides going out and curved

Question 7

The region of the brainstem represented by the left section is the _____; the region represented by the right section is the _____. The area encircled on the two pictures contains the fibers of the _____ tract.

Answer 7

midbrain; pons; corticospinal

Question 8

The parietal, temporal, and occipital lobes send efferent fibers to the pons. This _____ pontine tract follows the expected white matter route through the posterior limb of the _____ _____ and then through the _____ ______ of the midbrain.

Answer 8

corticopontine; internal capsule; basis pedunculi

Question 9

Another efferent tract from the frontal lobe to the pons follows a similar route, except that it passes through the _____ limb of the internal capsule. It is named the _____ pontine tract.

Answer 9

anterior; frontopontine

Question 10

Encircle and label the corticopontine tract and the frontopontine tract at the level of the internal capsule. In the basis pedunculi, the _____ tract is closest to midline.

Answer 10

corticospinal

Question 11

Number the following tracts as 1 to 3 in sequence, with I being most lateral and 3 being most medial in the basis pedunculi.

Answer 11

3- Frontopontine, 1- Corticopontine 2-Corticospinal

Question 12

Label tracts 1 to 3 on the figure with their names.

Answer 12

(From left- 1, 2, 3)
Corticopontine tract
Corticospinal tract
Frontopontine tract

Question 13

Fibers of tract “A” terminate in the _____. Fibers of tract “B” pass downward from the level of this section, successive through the _____ and _____ and into the _____ _____

Answer 13

pons; pons; medulla; spinal cord

Question 14

The line through the left hand diagram indicates the level of the section. From which region of the brainstem is the transverse section?

Answer 14

medulla

Question 15

The corticospinal fibers again form a compact bundle along the _____ surface of the medulla. At some levels of the medulla, the corticospinal fibers form a compact bundle with a pyramidal shape. Because of this shape, the portion of the corticospinal system that lies in the medulla is called the _____al tract.

Answer 15

anterior; pyramidal

Question 16

The pyramidal tract is _____ matter. The stain applied to the right side of this diagram colors the _____ matter (cranial nerve XII was drawn in on this diagram; it would not be stained in this way). On the right side, label the inferior olive, cranial nerve XII, and pyramidal tract.

Answer 16

white; gray
Inferior olive- two parts of squiggles on right side
Cranial nerve XII- little part protruding under squiggles

Question 17

Cranial nerve XII emerges from the brainstem between the inferior olive and the pyramidal tract. On both sides of the diagram, indicate its point of emergence with arrows. Cranial nerve XII, the inferior olive, and the pyramid all help to identify a transverse section across the _____.

Answer 17

medulla
Point arrow on both sides at line in bottom