KMS - Lecture 8 & 9 - Cranial Meninges Flashcards Preview

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Flashcards in KMS - Lecture 8 & 9 - Cranial Meninges Deck (24):

What are the layers, starting with cerebral cortex, of the meningeal layers?

Cortex/brain cells
Pia mater
Subarachnoid space with arachnoid trabeculae
Dura layer


What tissue makes up pia mater?

Areolar CT


How are the tissues different between pia and arachnoid mater?

Arachnoid has somewhat more dense CT layer than pia - more elastic and collagen fibers


What forms the subarachnoid space? What are the contents?

Trabeculated deep surface of arachnoid mater
Contains CSF, cerebral aa and veins


What covers the brain? What dips into sulci?

Pia - covers, dips into sulci, invests vessels
Arachnoid - covers, doesn't dip into sulci except for longitudinal fissure
Dura - covers, doesn't dip into sulci - forms reflections


What forms cisterns?

Cisterns = areas of accumulated CSF
- formed by arachnoid mater and contours of the brain


What forms CSF (cerebrospinal fluid)?

Choroid plexus
- modified tuft of capillaries in the ventricles


How does CSF get into the sub-arachnoid space?

CSF flows through ventricles to 4th ventricle
- openings then communicate with sub-arachnoid space


Where is CSF reabsorbed? What structure is involved?

Into the superior sagittal sinus via arachnoid granulations


What tissue is the dura mater? What is it continuous with?

Dense fibrous CT layer enclosing brain
- continuous with spinal dura at foramen magnum


What is the periosteal layer of dura?

periosteum of cranial vault adherent to meningeal dura


What is the meningeal layer of dura? What do they form?

duplications of dura - prolonged between major portions of the brain
- form dural reflections


What meningeal layer eventually fuses with neural sheaths?

Dura mater - prolonged along cranial nerves


Name the 4 dural reflections.

Falx Cerebri
Tentorium Cerebelli
Falx Cerebelli
Diaphragma Sellae


What sinuses are in the falx cerebri?

Superior sagittal sinus
Inferior sagittal sinus


What are the attachments and shape of the falx cerebri?

Anterior- crista galli of ethmoid
- forms a sickle shape between hemispheres
Posterior - continuous with tentorium cerebelli at internal occipital protuberance

Follows contour of sagittal suture in its course


What forms a tent over the posterior cranial fossa? What separates cerebellum from posterior cranial hemispheres?

Tentorium cerebelli


What sinuses does the tentorium cerebelli enclose?

Transverse sinuses
Superior petrosal sinuses


Where does the tentorium cerebelli attach?

Anterior - ant. and post. clinoid processes of sphenoid bone
Periphery - occipital bone at grooves for transverse sinus


What is the tentorial notch?

Free anterior concave margin of tentorium which wraps around midbrain


Which dural reflection can kill you? How?

Tentorial notch on tentorium cerebelli
- can transect midbrain during rapid deceleration or loss of CSF


What is the span of the falx cerebelli?

Extension of dura
Runs between cerebellar hemispheres
Runs from tentorium above to occipital crest below


What does the falx cerebelli contain?

Occipital sinus


What is the diaphragma sellae? What does it cover?

Specialized portion of dura
Forms roof over hypophyseal fossa