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

Pia mater – soft, thin, delicate

Arachnoid – delicate network

Dura – tough, fibrous

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

EpendymaPia

The “hollow” brain 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 + 2)

3

4

Lateral (1 + 2)

3rd

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!