PHGY 209 Lecture Notes - Lecture 21: Arachnoid Granulation, Pia Mater, Cerebrospinal Fluid

• School: McGill University
• Department: Physiology
• Course: PHGY 209
• Professor: Ann Wechsler

Document Summary

Embryonic disk --> neural plate --> neural groove --> neural tube + neural crest --> neural tube becomes cns, and part of pns. Week 4: neural crest become part of pns; neural tube becomes cns, and part of pns. Vesicles develop during week 4: forebrain, midbrain, hindbrain. Four ventricles: 2 lateral ventricles, third ventricle, fourth ventricle. Chloroid plexus lines ventricles (in all 4 ventricles, but mainly in the 2 lateral); it oozes out csf (cerebral spinal fluid) into the ventricles. Removes waste thru absorption at the arachnoid villi, which takes the. Csf wastes and dump them into the venous blood supply. Csf is passive: not pumped around, just flows freely in the brain. Csf has to get out of the brain. Csf enters the subarachnoid space via openings called foramens of. If csf does not get out of the brain, it could squash the brain => hydrocephalus (too much csf in the brain)