Brainstem

Question 1

What is medial geniculate body?

Answer 1

The medial geniculate body (MGB) is a structure located in the thalamus, specifically in the posterior part of the thalamus.
It serves as a relay station for auditory information, receiving input from the inferior colliculus of the midbrain and transmitting it to the auditory cortex in the temporal lobe of the cerebrum.

Question 2

What are cerebral preduncles?

Answer 2

Cerebral peduncles are bundles of nerve fibers that connect the cerebrum to other parts of the brain, specifically the midbrain. They are involved in transmitting motor signals from the cerebral cortex to the spinal cord, as well as sensory information from the brainstem to the thalamus.

Question 3

Trochlear nerves wind around lateral aspect of midbrain to enter the lateral wall of ?

Answer 3

Cavernous sinus

Question 4

Floor of the interpreduncle fossa consists of?

Answer 4

Posterior perforated substance

Question 5

1.Trochlear nerve immerges?
2. Occulomotor nerve emerges?

Answer 5

1.In the midline below inferior colliculi

2. From the groove on the medial side of crus cerebri

Question 6

The most anterior & posterior part of cerebral preduncles of midbrain?

Answer 6

Most anterior : crus cerebei
Posterior to it: tegmentum
Most posterior: tectum

Question 7

What is cerebral aqueduct?

Answer 7

A narrow cavity of midbrain that connects 3rd & 4th ventricle

Lined by ependyma & surrounded by central gray matter

Question 8

1.Which nuclei is present at the level of inferior colliculi?

2. Fibres of trochlear nuclei pass laterally & posteriorly & exit the midbrain?
3. Fibres of trochlear nucleus then decussate completely in the?

Answer 8

1. Trochlear nucleus + mesencephalic nuclei of trigeminal nerve
2. Just below the inferior colliculi
3. Superior medullary velum

Question 9

1. The central part of tegmentum is occupied by?
2. The reticular formation of the midbrain is ______ than that of pons and is ______ to the decussation?

Answer 9

1. Decussation of superior cerebral preduncles
2. Smaller & lateral

Question 10

To which geniculate bodies do the superior & inferior colliculus connect?

Their control?

3. The afferent pathway for light reflex ends in?

Answer 10

Superior—–lateral
Inferior—–medial

Superior—visual
Inferior—-auditory

3. Pretectal nucleus

Question 11

Which leminisci are present in superior & inferior colliculi level?

Answer 11

Median leminiscus
Spinal leminiscus
Trigeminal leminiscus
Lateral leminiscus (not present at the level of superior colliculi)

Question 12

Reticular formation in midrbrain is suituated in the?

Answer 12

Tegmentum