Presentationabout : Presentationabout Meninges
Brain Made by : Beshoy Nabil
Section : 4 OBJECTIVES : OBJECTIVES The Meninges : The Meninges The brain and spinal cord are enclosed by three membranous coverings or meninges
The Dura mater
The Arachnoid mater
The Pia mater The Meninges : The Meninges The Meninges : The Meninges DURA MATER : DURA MATER It’s a thick membrane forming the outermost covering of the brain .
- It consists of 2 layers
Outer ( endosteal ) layer
Inner ( meningeal ) layer DURA MATER : DURA MATER Endosteal layer Meningeal layer DURA MATER : DURA MATER 4) Diaphragma sellae 3) Falx cerebelli 2) Tentorium cerebelli 1) Falx cerebri The Falx Cerebri : The Falx Cerebri It is a sickle-shaped fold of dura mater that lies in the midline between the two cerebral hemispheres.
Its narrow end in front is attached to the internal frontal crest and the crista galli.
Its broad posterior part blends in the midline with the upper surface of the tentorium cerebelli. Superior sagittal sinus Falx cerebri Frontal crest Crista galli Inferior sagittal sinus Straight sinus The Falx Cerebri : The Falx Cerebri - The superior sagittal sinus runs in its upper fixed margin, the inferior sagittal sinus runs in its lower concave free margin, and the straight sinus runs along its attachment to the tentorium cerebelli. Crista galli The Falx Cerebelli : The Falx Cerebelli The falx cerebelli is a small, sickle-shaped fold of dura mater that is attached to the internal occipital crest and projects forward between the two cerebellar hemispheres.
Its posterior fixed margin contains the occipital sinus 3) Falx cerebelli The Tentorium Cerebelli : The Tentorium Cerebelli The tentorium cerebelli is a crescent-shaped fold of dura mater that roofs over the posterior cranial fossa.
It covers the upper surface of the cerebellum and supports the occipital lobes of the cerebral hemispheres. The Tentorium Cerebelli : The Tentorium Cerebelli The falx cerebri and the falx cerebelli are attached to the upper and lower surfaces of the tentorium , the straight sinus runs along its attachment to the falx cerebri , the superior petrosal sinus along its attachment to the petrous bone , and the transverse sinus along its attachment to the occipital bone . The Diaphragma Sellae : The Diaphragma Sellae The diaphragma sellae is a small circular fold of dura mater that forms the roof for the sella turcica.
A small opening in its center allows passage of the stalk of the pituitary gland Nerves and Blood Supply : Nerves and Blood Supply Arachnoid mater : Arachnoid mater It is named so because it has a spider web like appearance
-it is a thin transparent nonvascular membrane located between the dura mater and the pia mater.
-it is separated from the dura
by subdural space
Separated from pia mater by the subarachnoid space (filled with CSF) Subarachnoid Space : Subarachnoid Space -It is a space between the arachnoid and the pia mater
it surrounds the brain and spinal cord, and ends below at the lower border of S2
it contains CSF and the large vessels of the brain. Cranial nerves pass through the space
It’s dilated in certain areas to form subarachnoid cisterns Subarachnoid Space : Subarachnoid Space Subarachnoid Cisterns : Subarachnoid Cisterns These are dilatations of the subarachnoid space which contains the CSF
They are named after the structure over which they lie Subarachnoid Cisterns : Subarachnoid Cisterns Pia Mater : Pia Mater Is a delicate highly vascular membrane that closely invests the brain and the spinal cord
The pia mater forms the Tela Choroidea
The tela choroidae fuse to form the choroid plexus
Choroid plexus forms CSF Pia mater Pia Mater : Pia Mater Slide 25: Choroid plexus of lateral ventricle Ependyma Pia mater of tela choroidae Choroid plexus of 3rd ventricle Slide 26: The End