Changes

mater of the cranium and drains the cerebral cortex, the cortex of the cerebellum, the deeper telencephalon, part of the diencephalon, and the tectum of the midbrain.  The ventral (basilar) system lies on the floor of the cranial vault and drains the brainstem. The dorsal and ventral systems have minimal connection between them, but each communicates with the extracranial venous system.  The dorsal system begins where several dorsal cerebral veins converge in the area of the '''crista galli''' of the '''cribriform plate'''.  The '''dorsal sagittal sinus''' arises from this convergence and runs caudally along the dorsal midline; surrounded by the falx cerebri as it lies against the skill bones.  Along its course, it receives '''cerebral veins''', '''meningeal veins''', and '''diploic veins''' from the skull.

mater of the cranium and drains the cerebral cortex, the cortex of the cerebellum, the deeper telencephalon, part of the diencephalon, and the tectum of the midbrain.  The ventral (basilar) system lies on the floor of the cranial vault and drains the brainstem. The dorsal and ventral systems have minimal connection between them, but each communicates with the extracranial venous system.  The dorsal system begins where several dorsal cerebral veins converge in the area of the '''crista galli''' of the '''cribriform plate'''.  The '''dorsal sagittal sinus''' arises from this convergence and runs caudally along the dorsal midline; surrounded by the falx cerebri as it lies against the skill bones.  Along its course, it receives '''cerebral veins''', '''meningeal veins''', and '''diploic veins''' from the skull.

The dorsal sagittal sinus of the horse, is incompletely divided by a septum and bifurcates rostral to the '''osseous tentorium'''. Just before reaching the osseous tentorium, the dorsal sagittal sinus

The dorsal sagittal sinus of the horse, is incompletely divided by a septum and bifurcates rostral to the '''osseous tentorium'''. Just before reaching the osseous tentorium, the dorsal sagittal sinus

receives a single sinus that drains the '''medial cortex''', '''corpus callosum, '''basal ganglia''', and part of the '''diencephalon'''. The '''transverse sinuses''' run ventrally from the '''osseous tentorium''' to the '''retroarticular foramen''', where they exit to join the '''extracranial venous system'''.

receives a single sinus that drains the '''medial cortex''', '''corpus callosum, '''basal ganglia''', and part of the '''diencephalon'''. The '''transverse sinuses''' run ventrally from the '''osseous tentorium''' to the '''retroarticular foramen''', where they exit to join the '''extracranial venous system'''. The transverse sinuses receive the '''dorsal petrosal sinuses''', which mainly drain the '''rhinencephalon'''. They also receive veins from the caudal cerebrum, dorsal midbrain and the meninges. The transverse sinuses are connected  via the '''communicating sinus''' without directly joining to the dorsal saggital sinus in the horse.

===Spinal Cord===

===Spinal Cord===