Cranial Cavity Lecture Flashcards
What venous blood vessels pass from the scalp, through though the skull, and into the dural venous sinuses?
Emissary Veins
What are the 2 layers of the skull and what’s in them?
- Outer Dense Layer
2. Inner Spongy Layer, houses DIPLOIC Veins and Red Bone Marrow
What is the relationship between diploic veins and emissary veins and what risk do they pose?
- Diploic veins, like emissary veins, drain into dural sinuses
- These two vein types communicate
- Provides a route for SPREAD of INFECTION from scalp to Cranial Vault
Name 4 of the emissary veins.
- Parietal
- Mastoid
- Occipital
- Condylar
T or F: since the superior and inferior opthalmic veins connect with the cavernous sinus, they can be considered emissary veins
True
What meningeal layer carries blood vessels to the brain and cord?
pia mater
Which layer of the meninges becomes continuous with the pericranium (periosteum of the skull surface) at the foraminae?
Periosteal layer of Dura Mater
What are the boudaries of the Falx Cerebri?
- Anterior, Posterior, and superior attachments
- Found in Longitudinal Fissure (between the two hemispheres)
- Runs from CRISTA GALLI to INTERNAL OCCIPITAL PROTUBERANCE where it fuses with Tentorium Cerebelli
- Superiorly it runs on midline of CALVARIA
What Sinuses are associated with the Falx Cerebri?
Superior:
- attachment contains Superior Sagittal Sinus
Inferior (free margin):
- Inferior Sagital Sinus
Posterior:
- Fusion to Tentorium Cerebelli form STRAIGHT Sinus
What structure meets the falx cerebri at a right angle and is continuous with it?
Tentorium Cerebelli
What does the Tentorium Cerebelli divide?
Cerebellum from occipital pole of cerebral hemispheres
What are the boundaries of the Tentorium Cerebelli?
Anteriorly:
Petrous Temporal Bone and Posterior Clinoid Process
Posteriorly and Laterally: Transverse Sinuses (of Occipital bone)
Posteriorly and Medially:
Continous with Falx Cerebri at 90º angle
What separates the two cerebellar hemispheres?
Falx Cerebelli (Dural Partition)
*Note this attaches to the occipital bone and inferior surface of Tentorium Cerebelli
What Dural partition forms a roof over the pituitary and is pierced by pituitary stalk?
- Diaphragma Sallae
What is the attachment of the Diaphragma sellae and what sinus is associated with it?
- Hypophyseal Fossa
- Intercavernous Sinus
What drains virtually all of the venous blood contained in a cranial vault?
Dural Venous Sinuses
What structures drain blood of the brain substance into the Dural Venous Sinuses?
Cerebral and Cerebellar Veins
Where does blood and CSF go after leaving the dural sinuses?
Internal Jugular Veins
What forms the base and sides of the triangular dural venous sinuses?
Base (superior): Periosteal Dura Mater
Sides: Meningeal Layer of Dura Mater
You get Meningitis in your Superior Sagittal Sinus, how did it get there from the outside?
- Superior Sagittal Sinus Communicates with DIPLOIC and EMISSARY veins from scalp
- Bacteria enters from the scalp to the superior sagittal sinus
Pathogens traveling through Mastoid and Condyloid emmissary veins would infect which sinus?
Sigmoid Sinuses
Where are the Cavernous sinuses.
Either side of the Sphenoid Bone
How could an infection spread from the left or right cavernous sinus move to the cavernous sinus on the opposing side?
Entry to Left Sinus Via:
Opthalmic Veins
Veins of the Deep Face (Pterygoid Plexus)
Superior and Inferior Petrosal Sinuses
Movement to opposing side via:
Intercavernous Sinuses
Where do the meningeal arteries arise from?
External Carotid => Maxillary Artery => Middle Meningeal a.
What is the path middle meningeal arteries to the outside of the skull?
- Ascend through Foramen Spinosum
- Course OUTSIDE periosteal layer
**Note these groove the skull
What type of injury often injures the middle meningeal arteries and what would this disrupt blood supply to?
- Frequently injured in Skull Fractures
- Skull and Dura are supplied by this artery