Mesencephalon

• The mesencephalon is characterized by basal and alar plates
• Tegmentum is an area formed from the basal plates that are neuron-rich
• The alar plates give rise to the two superior colliculi, which control ocular reflexes, and two inferior colliculi, which serve as relays in the auditory pathway.
• The tectum are colliculi that are visible as round protuberances on the dorsal surface of the midbrain
• The crus cerebri connects the cerebral cortex to the pons of the brainstem