lecture 21 - meninges & ventricular system Flashcards
How many layers make up the meninges?
3
What are the 3 layers of the meninges?
Dura mater, arachnoid mater, pia mater
What is the outermost layer of the meninges?
Dura mater
What layer of the meninges sits adjacent to the bone of the cranium?
Dura mater
What is the structural characteristic of the dura mater?
Dense, fibrous, tough
What is the structure of the dura mater?
Made of two layers (outer and inner) that are tightly adhered to each other except when gaps called venous sinuses form, or the inner layer forms dural folds in prominent fissures
What does the inner layer of the dura mater form, when it clings to major sulci?
Dural fold
What are dural folds formed from?
Inner layer of the dura mater
What is the purpose of the dural folds?
Seperate major divisions of the brain, provide stability of the brain within the cranium.
What are the 3 major dural folds?
Falx cerebri, Falx cerebelli, Tentorium cerebelli.
What is the Falx cerebri?
A dural fold that separates the cerebral hemispheres in the medial/sagittal plane.
What is the Falx cerebelli?
A dural fold that seperate the cerebellar hemispheres in the median/sagittal plane
What is the Tentorium cerebelli?
A dural fold that separates the cerebrum from the cerebellum in the horizontal plane.
What is a venous sinus?
A gap between the inner and outer layers of the dura mater, where they diverge. Space collects veins/de-oxygenated blood and ‘old’ CSF.
Where is cerebrospinal fluid collected after it has cycled through the ventricular system?
In the venous sinuses.