User:Yanping Nora Soong/M1/neuroanatomy

Midbrain and basal ganglia

General vasculature and organization

The cerebral aqueduct divides the midbrain into dorsal and ventral portions.

Tectum

• Superior colliculus
• Inferior colliculus

Cranial nerves

Oculomotor nerve (III)

• Brainstem nucleus:

  Edinger–Westphal nucleus (parasympathetic pre-ganglionic neuron cell bodies that synapse onto the ciliary ganglion)

  Contributes the autonomic, parasympathetic component to the oculomotor nerve; ultimately innervating iris sphincter muscle and ciliary muscle

  Oculomotor nucleus - general somatic efferent fibers to the levator palpebrae superioris muscle, superior rectus muscle, inferior rectus muscle, medial rectus muscle and inferior oblique muscle

CNIII oculomotor nucleus in context

Neural tracts (ascending and descending)

Spinal cord tracts