Mesencephalon (M2)

Question 1

Where do all sensory fibers ascend in the mesencephalon on the way to the thalamus?

Answer 1

Tegmentum

Question 2

What cranial nerves nuclei are in the tegmentum?

Answer 2

III and IV

Question 3

What is the fluid filled tube of the mesencephalon called?

Answer 3

Aqueducts of Sylvius

Question 4

What is the dorsal section of the mesencephalon called?

Answer 4

Tectum

Question 5

What is the ventral section of the mesencephalon called?

Answer 5

Crus Cerebri

Question 6

What is the space between the two cerebral peduncles called?

Answer 6

Interpeduncle Fossa

Question 7

What is the result from a lesion that compresses the left cerebral peduncle?

Answer 7

Spastic paralysis of the right

Question 8

What are the four bumps on the tectum of the mesencephalon collectively called?

Answer 8

corpora quadrigemina

Question 9

What is the superior colliculus of the tectum of the mesencephalon involved with?

Answer 9

vision

Question 10

What is the inferior colliculus of the tectum of the mesencephalon involved with?

Answer 10

hearing

Question 11

What ventricle is continuous with the Aqueduct of Sylvius?

Answer 11

4th Ventricle

Question 12

What surrounds the aqueduct of Sylvius?

Answer 12

periaqueductal grey matter

Question 13

What fibers connect the red nucleus and the cerebellum? 1. And what direction do these fibers run? 2

Answer 13

1. rubro cerebellar fibers

2. dorsal caudal (down)

Question 14

Where is the corticospinal tract in the mesencephalon?

Answer 14

Crus Cerebri

Question 15

What is the difference in presentation with a crus cerebri damage instead of internal capsular damage?

Answer 15

1. No anesthesia in crus cerebri

2. Oculomotor nerve palsy in crus cerebri

Question 16

What is paralysis of the ciliary fibers called?

Answer 16

cycloplesia

Question 17

What side and muscles does the lateral nucleus of the oculomotor complex innervate?

Answer 17

Ipsilateral medial rectus, inferior rectus, and inferior oblique

Question 18

What is the lateral nucleus split into?

Answer 18

1. ventral
2. intermediate
3. dorsal

Question 19

What side and muscles does the dorsomedian nucleus of the oculomotor complex innervate?

Answer 19

Contralateral superior rectus

Question 20

What side and muscles does the central caudal nucleus of the oculomotor complex innervate?

Answer 20

Bilateral Levator (LPS)

Question 21

What side and muscles does the Edinger-Westphall nucleus of the oculomotor complex innervate?

Answer 21

Ipsilateral sphincter pupillae and ciliary body

Question 22

In regard to the oculomotor complex, what does parasympathetic damage result in?

Answer 22

Anisecoria with direct response diminished

Question 23

What does damage to the red nucleus result in? 1. What is this called? 2

Answer 23

1. Contralateral cerebellar ataxia, ipsilateral oculomotor problems and touch,vibration, 2 pt. discrimination
2. Benedicts

Question 24

What direction does the trochlear nerve move from the nucleus? 1. Where does it exit the brain stem? 2

Answer 24

1. dorsal caudal

2. below inferior colliculus

Question 25

Where does the trochlear nerve decussate?

Answer 25

superior/anterior medullary vellum

Question 26

What is a strabismus that varies in size depending on where you’re looking?

Answer 26

Incominant

Question 27

If there is right trochlear nucleus damage what side will the patient have a head tilt?

Answer 27

right side

Question 28

If there is bilateral superior oblique palsy what side will the patient have a head tilt?

Answer 28

No head tilt

Question 29

What central nerves does the Medial longitudinal fasciculus involve?

Answer 29

III, IV, VI, and VIII