week 7 Flashcards
meninges
three connective tissue membranes that lie just external to the CNS organs
what are four major functions of the meninges
- cover and protect the CNS
- Protect blood vessels and enclose venous sinuses
- Contain cerebrospinal fluid
- Form partitions in the skull
list the meninges from external to internal
dura mater, arachnoid mater, pia mater
describe the layers of the dura mater
There is the more superficial periostreal layer which attaches to the inner surface of the skull, and there is also a deeper meningeal layer.
dural venous sinuses
the brain’s two dural layers are fused together except in certain areas, where they separate to enclose dural venous sinuses that collect blood from the brain and direct it into the internal jungular veins of the neck, heading for the heart
dural septa
extensions of the dura mater which separate parts of the brain and limit excessive movement of the brain within the cranium
- Falx cerebri
- Falx cerebelli
- Tentorium cerebelli
Falx cerebri
separates the two hemispheres of the cerebrum
Falx cerebelli
separates the two hemispheres of the cerebellum
Tentorium cerebelli
separates the cerebrum from the cerebellum
subdural space
A narrow cavity containing a film of fluid which separates the dura mater from the arachnoid mater.
Veins of the brain (“bridging veins”) are situated within this space and carry venous blood to the dural sinuses
subarachnoid space
Spider-web-like extensions span this space and secure the arachnoid mater to the underlying pia mater.
It is filled with CSF and contains the largest blood vesels serving the brain.
arachnoid villi
Knoblike projections of the arachnoid mater which protrude through the dura mater and into the superior sagittal sinus.
They absorb CSF into the venous blood of the sinus
pia mater
layer which “hugs” the brain like cellophane wrap
Inner blood vessels circulate within this layer
Cerebrospinal Fluid
forms a liquidy cushion that gives buoyancy to CNS structures and protects the brain from physical and chemical injuries via the CSF-brain barrier
helps nourish the brain by supplying it with nutrients and oxygen
CSF is produced by:
plasma filtration via the ependymal cells in the choroid plexus (make and filter CSF from blood)