Meninges and Dural Sinuses (lab)

Pachymenix

Thick layer, DICT

Dura mater, heavily vascularized and adhered to skull casing

Leptomeninges

Arachnoid and Pia mater

Arachnoid trabecula

Connect arachnoid to pia mater, run in subarachnoid space between arachnoid and pia

Pia mater

Gentle matter

Connects to brain itself

Dura mater

Follows contours of skull, covers all foramen so nerves and vessels pierce it with tight seals to prevent CSF leakage

Middle meningeal artery

Within epidural space, external to dura mater

Epidural hematoma

Most common skull fracture site, middle meningeal artery runs right under pterion

Rupture of artery and blood fills space → Results in uncal herniation by pushing brain

Picked up by CT scans

Epidural space

Potential space

Has vessels running within, empty in health

Uncal herniation

As uncus moves medially, it can push CNIII in mesencephalon

Dilated pupil first affected because PNS runs on outside of nerve

Subs layers of dura

Periosteal dura: Runs along osteum of skull

Meningeal dura: Reflects away from skull at dural veins/sinus

Falx cerebri

DICT that separates 2 hemispheres

Creates superior sagittal sinus and inferior sagittal sinus

Tentorum cerebelli

DICT that is the roof of the cerebellum

Area where it meets falx cerebri is where the inferior sagittal sinus ends → Straight sinus