What is the interpeduncular fossa and where is it located?

The interpeduncular fossa is a rhomboid space on the base of the brain. It is bounded laterally by the crura cerebri, anteriorly by the optic chiasma and tracts, and posteriorly by the pons.

What structures are found within the interpeduncular fossa?

The interpeduncular fossa contains several key structures: mammillary bodies, tuber cinereum, infundibulum, posterior perforated substance, and the oculomotor nerve (III) emerges here.

Which cranial nerve is the exception to ventral brain attachments, and why?

The trochlear nerve (IV) is the exception because it emerges dorsally from the midbrain, unlike all other cranial nerves which attach to the ventral surface of the brain.

Where does the oculomotor nerve (III) attach on the base of the brain?

The oculomotor nerve (III) emerges from the medial side of the cerebral peduncle within the interpeduncular fossa.

What are the key anatomical areas visible on the base of the brain?

The base of the brain includes: orbital and tentorial surfaces of the frontal and temporal lobes, interpeduncular fossa, ventral surfaces of the midbrain, pons, medulla oblongata, and cerebellum, and sites of superficial cranial nerve attachments.

How are the trigeminal nerve (V) and abducent nerve (VI) attached to the brainstem?

The trigeminal nerve (V) attaches to the pons with two roots (sensory and motor). The abducent nerve (VI) emerges at the lower border of the pons near the medullary pyramid.

Base of Brain – Ventral Anatomy & Cranial Nerve Attachments