Venous sinuses Superior SS . Inferior SS join the Great vein of Galen Straight sinus. SSS, straight S, and two transverse S. frequenly join (confluence of sinuses). Straight S Sigimoid S Int Jugular vein.
Cavernous sinus Intercavernous comunications. Tributaries: Sup and Inf Ophthalmic veins, sup cerebral vein. Drainage: Sup and Inf petrosal sinus Internial Jugular vein ( direct ) or via transverse sinus Int Jug vein.
Trochlear Nerve Two nuclei in mesencephalon ventral to inferior colliculi. Close to caudal end of IIIrd nerve nuclei. Only somatic nerve to emerge from the dorsal aspect of the CNS. Decussation (anterior medullary velum ). Nucleus: anterior to periacqueductal gray matter.
Trochlear nerve Around the crus cerebri between PCA and Sup cerebell art (lateral to 3rd nv.) beneath the free edge of the tentorium Pierces the dura and enters the lateral wall of the cavernous sinus beneath the 3rd cranial nerve.
Abducens Nerve Midpons beneath the facial colliculus. Longest course.
Abducens Nerve Emerges at pontomeduallry junnction.
Abducens Nerve Pierces the dura early upward onThe clivus.Vertical Horizontal direction.Runs beneath the petroclinoid(Guber’s) Ligament.Within the cavernous sinus (lateralto the ICA).
Trigeminal nerve Gessarian ganglion : Temporal bone within middle cranial fossa (Meckel’s cave). V1 SOF , V2 FR , V3 FO.
Trigeminal nerve V1Sensory. V2 carries PS from The facial (superficial Petrosal nv.) for Lacrimation, V3 Motor and Sensory.
Facial nerve Supranuclear neurons : in the frontal lobe (pre-central gyrus). Corticobulbar fibers in the middle of internal capsule. Fibers cross (below MB) cross to innervate contralateral facial nucleus , some to ipsilateral.
Facial Nerve Ventrolateral pons : Facial motor root and 8th nerve exit togather. CPA: Vth, VIIth and VIIIth lie close togather. Facial motor root internal auditory meatus Fallopian canal. At geniculate ganglion: first branch of VII is Greater superficial petrosal nv. sphenopalatine ganglion lacrimal gland.