What are the 3 Protective Mechanisms of the brain and spinal cord?
Skull & Vertebra
Mechanical Suspension and connection of the brain via meningeal layers
Cerebrospinal Fluid
What are the 3 Meningeal Layers?
Dura Mater
Arachnoid Complex
Pia Mater
Find the 3 Meningeal Layers
Dura Mater
Tough thick layer that adheres to the periosteum
What are the layers of Dura Mater?
Periosteal Layer
Inner Dural Layer
Which layer of Dura Mater adheres to the inner skull surface?
The periosteal layer
What are the two "potential" Dural Spaces?
The Epideral seperation between the cranium and the periosteal dural layer, and subdural separation between the dura and the arachnoid layer.
Arachnoid Complex
A thin, avascular membrane composed of a few layers of cells interspersed with bundles of collagen.
What part of arachnoid complex adheres to the inner dural layer?
The superficial layer of the arachnoid complex
Arachnoid Trabeculae
Small strands of collagen that emerge from the interface of arachnoid complex and merge with the pia mater.
Subarachnoid Space
space between the arachnoid complex and the pia matter that contains CSF and allows neural tissue to float.
Pia Mater
Thin, delicate membrane that closely invests all the folds of the cerebral and cerebellar neural tissue.
Dural Reflections (Septa)
Dural reflections are places where the outer layer and inner layer seperate normally.
The outer layer of septa...
adheres to the cranium
The inner layer of septa...
follows the neural tissue into the cranial cavity
The most prominent dural reflections are...
the falx cerebri and the tentorium cerebelli
The seperations of septa are filled with...
deoxygenated blood. they create sinuses.
Falx Cerebri
A long, arched vertical dural reflection that occupies the longitudinal fissure and is anteriorly attached to the crista galli of the ethmoid bone
The Falx Cerebri seperates...
the left and right cerebral hemispheres
Falx Cerebri
creates the straight sinus
Tentorium Cerebelli is located:
dural reflection located between the inferior surface of the cerebral hemispheres and the superior aspect of the cerebellum.
The Tentorium Cerebelli seperates...
the occipital and temporal lobes from the cerebellum.
Tentorial Notch
The space in the tentorium through which the brain stem passes.
Tentorium Cerebelli and Falx Cerebri
Name two small reflections
Falx Cerebelli
Diaphragma Sellae
Falx Cerebelli
a small septum that partially separates the cerebellar hemispheres
Diaphragma Sellae
Covers the pituitary fossa and infundibulum at the base of the skull
Dural Sinuses are created...
by the spaces between dural reflections (dural layers) to drain everything out of the cerebral veins.
Major Sinuses
Superior Sagittal Sinus, transverse sinus, straight sinus
Minor Sinuses
Inferior Sagittal Sinus/ Sigmoid Sinus
Superior Sagittal Sinus
Inferior Sagittal Sinus
Transverse, Sigmoid, and Sphenoparietal Sinuses
Dural Sinuses
Find the superior sagittal, inferior sagittal, transverse, sigmoid, straight, and sphenoparietal sinuses.
Torculas of Herophili
Confluence of Sinuses- they all come together here
Sub-Arachnoid Cisterns
Deep holes created between the arachnoid and pial layers.
The only substantial fluid-filled CSF spaces around the brain are...
Sub-Arachnoid Cisterns
Sub-Arachnoid Cisterns are created when...
1. The outer arachnoid layer adheres to the meningeal dura AND
2. The trabeculae attached to the pia mater follow depressions in the neural tissue.
What are the 4 Sub-Arachnoid Cisterns?
1. Cisterna Magna
2. Quadrigeminal Cistern
3. Prepontine Cistern
4. Interpeduncular Cistern
Cisterna Magna is...
(inferior to cerebellum)
Quadrigeminal Cistern is...
(superior to cerebellum)
Prepontine Cistern is...
(ventral&inferior to the pons)
Interpeduncular Cistern is...
(ventral & superior to the pons)
Find the 4 Sub-Arachnoid Cisterns
Arachnoid Villi
small evaginations of arachnoid protrude through dura into the sinuses to get out CSF.
Where are most Arachnoid Villi found?
Along the Superior Sagittal Sinus
Arachnoid Villi / Arachnoid Granulations
Arachnoid Granulations
Large arachnoid villi that can expand into the skull.
Pacchionian Bodies
Arachnoid granulations that have become calcified with age.
Middle Meningeal Artery
Artery that supplies blood to the other arteries, over the lateral surface of the brain. Largest!
Opthalmic Artery supplies
blood to the dura in the anterior part of the brain.
Vertebral Arteries supply
blood to the dura in the posterior aspects of the brain.
Trigeminal V
The Primary Sensory Nerve to the Head
Nerves follow...
The arteries and terminate near dural sinuses.