How to draw different sections of the brain stem Sanjaya Adikari Department of Anatomy

Anterior surface Posterior surface

Main nerve tracts in the spinal cord A B G C D E F

A.Posterior white columns B.Lateral corticospinal tract C.Anterior & posterior spinocerebellar tracts D.Anterior & posterior spinothalamic tracts E.Olivospinal, vestibulospinal, tectospinal tracts F.Anterior corticospinal tract G.Rubrospinal tract

Closed medulla at the level of decussation of pyramids Fasciculus gracilis Fasciculus cuneatus Nucleus gracilis Nucleus cuneatus Spinal tract of trigeminal nerve Spinal nucleus of trigeminal nerve Decussation of pyramids Pyramid Posterior spinocerebellar tract Anterior spinocerebellar tract Spinothalamic tract Spinal root of the accessory nerve Central canal Medial longitudinal fasciculus

Closed medulla at the level of decussation of medial lemnisci Fasciculus gracilis Fasciculus cuneatus Nucleus gracilis Nucleus cuneatus Spinal tract of trigeminal nerve Spinal nucleus of trigeminal nerve Decussation of medial lemnisci Pyramid Posterior spinocerebellar tract Anterior spinocerebellar tract Spinothalamic tract Hypoglossal nerve Spinal root of the accessory nerve Central canal Medial longitudinal fasciculus

Medulla Oblongata at the level of middle of the olivary nuclei Inferior medullary velum Cavity of 4 th ventricle Inferior cerebellar peduncle Vestibular & cochlear nuclei Olivary nucleus Olive Pyramid Anterior spinocerebellar tract Spinothalamic tract Spinal tract & nucleus of trigeminal nerve Vagus nerve Hypoglossal nerve Reticular formation Medial longitudinal fasciculus Tectospinal tract Medial lemniscus

Pons at the level of facial colliculus Superior medullary velum Cavity of 4 th ventricle Inferior cerebellar peduncle Spinal lemniscus Reticular formation Medial lemniscus Superior cerebellar peduncle Spinal tract & nucleus of trigeminal nerve Medial longitudinal fasciculus Facial colliculus Abducent nerve Facial nerve Pontine nuclei Transverse pontine fibres Corticospinal & corticonuclear fibres Vestibular nuclei

Midbrain at the level of inferior colliculus Trochlear nerve Inferior colliculus Cerebral aqueduct Medial longitudinal fasciculus Mesencephalic nucleus of trigeminal nerve Trigeminal lemniscus Spinal lemniscus Medial lemniscus Substantia nigra Cerebral peduncle Decussation of superior cerebellar peduncles Interpeduncular fossa Reticular formation Periaqueductal Gray Matter

Midbrain at the level of superior colliculus Oculomotor nerve Superior colliculus Cerebral aqueduct Medial longitudinal fasciculus Mesencephalic nucleus of trigeminal nerve Trigeminal lemniscus Spinal lemniscus Medial lemniscus Substantia nigra Cerebral peduncle Red nucleus Reticular formation Periaqueductal Gray Matter

PPRF = Paramedian pontine reticular formation Medial longitudinal fasciculus