medulla ( anterolateral aspect )

Median features of medulla (ventral vs dorsal surfaces)

Ventral: longitudinal median fissure.

Dorsal: median sulcus.

Both continuous with spinal cord counterparts.

What interrupts the ventral median fissure caudally?

Obliquely crossing fascicles of motor (pyramidal) decussation.

Where does the ventral median fissure end rostrally?

At pontine border in a depression called the foramen caecum.

Pyramid of medulla: location and content

Elongated ridge lateral to ventral

median fissure → contains descending corticospinal axons.

What marks the lateral margin of the pyramid?

Shallow ventrolateral sulcus.

Which nerve emerges from the ventrolateral sulcus?

Hypoglossal nerve rootlets (in line with ventral spinal nerve roots).

Where does the abducens nerve emerge?

At caudal border of pons, generally in line with hypoglossal rootlets.

Olive: location and content

Oval prominence lateral to pyramid

and ventrolateral sulcus → contains inferior olivary nuclear complex.

Which nerves emerge lateral to the olive and from where?

Glossopharyngeal and vagus nerves

emerge along posterolateral sulcus

(in line with dorsal spinal nerve roots).

Which nerves emerge superior to the olive and where exactly?

Facial and vestibulocochlear nerves

emerge in medullopontine sulcus

(supra-olivary fosette).