Corpus: Cerebral peduncle

The term pedunculi cerebri is a summarising term for two parts of the midbrain

• the crura cerebri (cerebral peduncle) and
• the mesencephalic tegmentum (midbrain bonnet).

The mesencephalic tegmentum forms the posterior part of the pedunculi cerebri. It contains important pathways and nuclei, including the substantia nigra, the nucleus ruber and the formatio reticularis. Dorsal to the mesencephalic tegmentum lies the tectum with the four-humped plate. The mesencephalic aqueduct is located between the tectum and tegmentum.

The cerebral crura are located ventral to the mesencephalic tegmentum. The corticospinal tract (pyramidal tract) and the following tracts run through them:

• Fibrae frontopontinae
• Fibrae corticonucleares
• Fibrae parietotemporopontinae

The pedunculi cerebri form the lateral boundary of the interpeduncular fossa, where the oculomotor nerve emerges. They are supplied by the peduncular rami of the posterior cerebral artery.