Anatomy [Week 2] Flashcards
What are the 3 CT layers of the meninges?
dura mater, arachnoid mater, pia mater
Where does the majority of venous blood flow in the brain?
dural venous sinuses (into the IJV)
What filters blood plasma to form CSF? Where is it located?
CHOROID PLEXUS; lining walls of all 4 VENTRICLES {flows out of 4th ventricle via apertures)
Where does CSF go from the APERTURES of the 4th VENTRICLE?
out of the median/lateral apertures into SUBARACHNOID SPACE between the arachnoid mater and pia mater
How does CSF get from the SUBARACHNOID MATER back into the VENOUS SINUSES?
via the ARACHNOID VILLI and capillary absorption
What composes the DURA MATER?
PERIOSTEAL and MENINGEAL layers
Where are the 2 layers of the DURA MATER separate?
inseparably bound through most of internal lining but separate at some locations to for DURAL SEPTAE and DURAL VENOUS SINUSES
To what is the PERIOSTEAL layer of the brain attached?
internal surface of the skull via SHARPEY FIBERS; strongly anchored to sutures
What is the MENINGEAL LAYER of dura mater? What special structures does it line?
continuous with dura mater lining internal surface of vertebral canal; envelopes CRANIAL NERVES
What are the DURAL SEPTAE?
folds of MENINGEAL LAYER of dural mater that restrict movement of brain within cranial vault
What is the FALX CEREBRI and where is it located?
layer of MENINGEAL dural mater vertically within longitudinal cerebral fissure; attaches to CRISTA GALLI anteriorly and to TENTORIUM CEREBELLI posteriorly
What is the TENTORIUM CEREBELLI and where is it located?
courses horizontally between PETROUS parts of temporal bone and internal lining of OCCIPITAL bone; separates occipital loves of cerebrum from cerebellum
What does the TENTORIUM CEREBELLI enclose?
TRANSVERSE and SUPERIOR PETROSAL sinuses
What is the DIAPHRAGMA SELLAE?
horizontal hood of DURA MATER that covers the PITUITARY GLAND over the SELLA TURCICA
What is the EPIDURAL SPACE?
potential space between CRANIUM and PERIOSTEAL LAYER of dura mater
When does an EPIDURAL SPACE appear?
pathology; ex. blood hemorrhaging from torn MIDDLE MENINGEAL ARTERY that separates dural mater from skull
Where does the PERIOSTEAL LAYER of the dura mater end and what does that mean for the EPIDURAL SPACE?
it ends at the FORAMEN MAGNUM, which means that it is separate from spinal epidural space
What is SUBDURAL SPACE?
not a natural space; seen during pathology-ex. rupture of cerebral-bridging vein where blood separates dura and arachnoid mater interface
What space is seen when there is a rupture of the CEREBRAL-BRIDGING VEIN?
SUBDURAL SPACE (between dura and arachnoid maters)
What is the LEPTOMENINGES and what is contained in in?
aka SUBARACHNOID SPACE; contains CSF, thin, CELLULAR TRABECULAE of arachnoid mater and many CEREBRAL VESSELS
Which type of cells and cell junctions primarily make up the ARACHNOID MATER?
squamous and cuboidal cells, desmosome cell junctions
What are ARACHNOID VILLI (granulations) and where are they located?
highly folded arachnoid mater projecting into the superior sagittal sinus (often produce indentations in inner surface of calvaria)
What is the purpose of ARACHNOID VILLI?
they are sites where CSF diffuses into blood of SUPERIOR SAGITTAL SINUS
What is the PIA MATER and where is it located?
a 1-2 cell thick layer following the traversing brain and covering blood vessels as they course into the fissures and sulci