Transcript Slide 1
Meninges, Ventricles, CSF Human Neurobiology ANHB 2217 Avinash Bharadwaj Semester 1, 2006 Week 2 Meninges Protective coverings for brain & spinal cord Meninges Dura mater Cranial Spinal Arachnoid mater Pia mater General Features Dura – tough, fibrous Arachnoid – delicate network Pia mater – soft, thin, delicate Other Names! Dura – Pachymeninx – ‘tough’ Arachnoid (like a spider’s web) + Pia – leptomeninges Cranial Dura Mater Bone Endosteal Sinus Meningeal Folds of Dura Falx – the sickle Occupies the longitudinal fissure between cerebral hemispheres Tentorium – the tent Covers the cerebellum The opening accommodates the brainstem Dural Venous Sinuses Veins with dural walls Separation of layers Spinal Dura Not adherent to bone except… Epidural and subdural spaces Ventricles Pia The “hollow” brain Ependyma Diagrammatic Cross Section Pia and Ependyma In some locations pia mater and ependyma come together. A plexus of blood vessels “invaginates” the thin layer. Cerebrospinal fluid enters the ventricle across this membrane. Ventricular System Lateral (1 +Lateral 2) (1 + 2) 3rd 3 4 4th Cerebrospinal Fluid Choroid plexus Ventricles Openings in the fourth ventricle Subarachnoid Space CSF – Back to Blood Arachnoid Granulations (and villi) Granulations Delicate projections into a sinus One-way flow into the sinus Increased pressure in the sinus blocks the flow Last slide!