the midbrain

what is the midbrain also known as?

mesencephalon

what are the functions of the midbrain?

- connects forebrain and hindbrain

- important for auditory and visual processing

- controlling movement

- regulating circadian rhythm (sleep/wake cycle)

- involved in reward systems

what opening does the midbrain travel through?

tentorium cerebelli

what are the 2 main parts of the mesencephalon?

- tectum

- paired cereberal peduncles

how are the cerebral peduncles further separated?

by substanstia nigra into:

- crus cerebri

- tegmentum

which is anterior out of the tegmentum and crus cerebri?

crus cerebri

where is the tectum located?

posterior to cerebral aqueduct

where are the paired cerebral peduncles located?

anteriorly and laterally to cerebral aqueduct, they converge at the pons

what does the tectum consist of?

4 colliculi - called the corpora quadrigemina

what are the 4 colliculi?

2 superior

2 inferior

where do the colliculi sit?

posterior to the pineal gland

which cranial nerve exits between the peduncles?

oculomotor nerve (CNIII)

which cranial nerves have nuclei located in the midbrain? (2)

- oculomotor (III)

- trochlear (IV)

what is the tectum involved in?

processing visual and auditory information

what is the tegmentum involved in?

- contains substantia nigra - so involved in motor control

- contains the red nucleus - so involved in coordinating limb movements

what is the function of the superior colliculi?

visual reflexes - turning head to a visual stimulus

what is the function of the inferior colliculi?

auditory reflexes - turning head to an audio stimulus