Neuroanatomy Lecture 10

Meninges

Dura Mater

outermost layer, tough and thick for protection, does not follow the contours of the tissue below it but goes over it

Two Sublayers of Dura Mater

periosteal and meningeal which are fused in most places but split apart to form sinuses

Periosteal Layer

closely adhered to the bone and next to the skull

Meningeal Layer

inner layer of the dura

Arachnoid Mater

middle layer, thinner than the dura, close to and usually connected to the dura, does not closely follow the contours of the tissue below it

Subdural Space

between the dura and the arachnoid layers, not usually a physical “space” but can fill with fluid in response to injury and swell

Pia Mater

innermost layer of the meninges, thin membrane covering the surface of the brain and spinal cord, closely follows the shape of the tissue below it into sulci, small capillary branches of surface blood vessels penetrate the pia and go into the brain

Subarachnoid Space

physical space between the arachnoid and the pia, CSF circulates through this space providing nutrients, surface capillaries run through this, just above the pia

Location where CSF is made

ventricles

Arachnoid Trabeculae

very fragile, thin threads of connective tissue that connect the pia to the subarachnoid layer

Meninges in the Spinal Cord

same meningeal layers as the brain, line the spinal cord as concentric tubes

Dural Reflections

meningeal layers of the dura fold inward and fuse to form dural reflections (creates space) that form a suspension system to protect the brain

Falx Cerebri

meningeal dura that lies within the longitudinal fissure and keeps the two cerebral hemispheres from colliding

Tentorium Cerebelli

covers the cerebellum and brainstem to keep the cortex from colliding with the cerebellum and/or brainstem