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Midbrain
Aka: Midbrain
- See Also
- Brain Stem
- Anatomy: Superior (Rostral) Midbrain Components
- Superior colliculus
- Superior (rostral) bump on each side of the upper Midbrain
- Visual reflex center (visual function, orientation of head and eyes)
- Aqueduct
- Single small midline CSF conduit
- CN 3 nucleus (Oculomotor Nerve)
- Medial, immediately anterior to aqueduct
- Cranial Nerves course anteriorly, and exit in the superior Midbrain at the midline
- Medial Geniculate Body
- Communication relay between the inferior colliculus and the auditory cortex
- Spinothalamic Tract
- Continued pain and TemperatureSensation tracts from the spinal cord
- Medial Lemniscus
- Proprioception Sensation from Posterior Columns (via Internal Arcuate Tract)
- Within the tract, head is represented anteriorly and legs posteriorly (as if standing on head)
- Red Nucleus
- Reflexive movement (e.g. crawling)
- Substantia Nigra
- Substantia Nigra's pars compacta produces Dopamine which is transmitted to the Dorsal Striatum
- Parkinsonism may result if deficient Dopamine production
- Corticospinal tract
- Continued motor tracts to the spinal cord
- Head is represented anteromedially and legs posterolaterally
- Anatomy: Inferior (Caudal) Midbrain Components
- Inferior colliculus
- Inferior (caudal) bump on each side of the lower Midbrain
- Aqueduct
- Single small midline CSF conduit
- CN 4 nucleus (Trochlear Nerve)
- Medial, immediately anterior to aqueduct
- Cranial Nerves exit posteriorly and immediately cross the midline (unique to CN 4)
- Spinothalamic Tract
- Continued pain and TemperatureSensation tracts from the spinal cord
- Medial Lemniscus
- Proprioception Sensation from Posterior Columns (via Internal Arcuate Tract)
- Crossings (Decussation)
- Superior Cerebellar Peduncles Decussation
- Substantia Nigra
- Substantia Nigra's pars compacta produces Dopamine which is transmitted to the Dorsal Striatum
- Parkinsonism may result if deficient Dopamine production
- Corticospinal tract
- Continued motor tracts to the spinal cord
- Anatomy: Images
- Rostral (superior cross-section)

- Caudal (inferior cross-section)

- Other cross sections
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
- References
- Gilman (1989) Manter and Gatz Essentials of Neuroanatomy and Neurophysiology, Davis, p. 81-96
- Goldberg (2014) Clinical Neuroanatomy, Medmaster, p. 24-39
- Netter (1997) Atlas Human Anatomy, ICON Learning, p. 108-12