Cranial Cavity and meninges Flashcards
Cranial fossae
- anterior
- Middle
- Posterior
Contain which brain lobes
- Frontal
- Temporal
- Occipital and Cerebellum
Features of anterior fossa
3
- Christa Galli
- Cribiform Plate
- Edges of lesser wings of sphenoid made its border with the middle fossa
- The christa galli is
- is located
- Attaches to
- A process of the ethmoid bone
- Between the cribiform plates
- The falx Cerebri
Key features of Middle cranial fossa
9
- Otbital fissure
- Optic canal
- Hypophyseal Sella turcica
- Imprints of the cavernous sinus
- Foramen rotundum
- Foramen Ovale
- Foramen Lacerum
- Foramen Spinosum
- Posterior border is the petrous Temporal Bone.
- The Hypopyseal sella turcica contains
- is also called
- The Pituitary Gland
- Also called the pituiary fossa
The Middle meningeal artery
- Origin and Course
- What are its branches
- Which is clinically significant and why?
- Is supplied by the External carotid
- Enters the cranial Cavity via the foramen Spinosum
- Anterior (to fronal and anterior half of parietal)
- and posterior (to rest of parietal and occipital)
The anterior passes near the pterion: the sphenoparietal stuture and the wing of the sphenoid bone is the thinnest part of the skull, prone to breakage. If a superdural haemorrage occurs there, the brain is compressed, and so are the contralateral breathing centers in the contralateral medulla. Eupnea is disrupted, leading to death from an apparently trivial injury.
Posterior cranial fossa features
5
- Internal acoustic meatus
- Jugular foramen
- Hypoglossal Foramen
- Foramen Magnum
- Grooves for transvers and sigmoid sinuses
Hydrocephalus
- Blockage in the ventricles
- The Choroid Plexus continues to produce CSF
- Intracranial pressure grows
- Can result in brain damage and a highly swollen/expanded skull if it occurrs in childhood.
Layers of dura in the cranium
3
- Periosteal layer (inner periosteum)
- Endosteal / Meningeal layer
- Spaces between these layers form the venous sinuses.
Periosteum at stutures
Is continuous.
This allows some flexibility in the foetal skull to accomodate growth.
Role of dural folds
To disperse pressure of head movements so specific regions of the brain are not damaged.
The Falx Cerebri Separates the hemispheres
The Tentorum Cerebelli separates the cerebellum from the cerebrum.
Cranial Venous sinuses (16)
- Superior Saggital Sinus
- Right Transverse Sinus
- Inferior Saggital sinus
- Great Cerebral Vein
- Straight Sinus
- Confluence of Sinuses
- Left Transverse Sinus
- Ophthalmic vein
- Cavernous sinus
- Sigmoid sinus
- Occipital Sinus
- Superior Petrosal Sinus
- Inferior Petrosal Sinus
- Sigmoid / Basilar Sinus
- Vertebral Vein
- Internal Jugular Vein
Cranial Bleeding types
Epidural Hematoma
Subdural hemaoma
Epidural Hematoma
5
- Skull fracture: Outer periosteum ruptured
- Meningeal Artery rupture
- Pressure separates Periosteal and endosteal layers of dura,
- cavity fills with blood and the brain is compressed
- Occurs in injuries to the Pterion
Subdural Hematoma
Bridging Vein or Arachnoid granulation is ruptured.
Venous blood (usually) enters the subdural space.
Now the more active tissue of the arachnoid is compressed.
