cranium, meninges and brain Flashcards
meninges: describe the arrangement of the meninges, describe the reflections of the dura mater and the formation of the venous sinuses
3 layers of meninges (outside to inside)
dura mater, arachnoid mater, pia mater
features of dura mater
thick, inelastic, 2 layers
2 layers of dura mater and contact
periosteal (outer towards periosteum) and meningeal (inner towards brain); largely stuck together in brain, but at points peel away to form structures to anchor brain or fill with blood (sinus)
what is periosteum
vascular connective tissue enveloping bones
where does cranial dura mater meet spinal dura mater
foramen magnum (periosteal dura fuses with skull at foramen magnum and doesn’t continue into vertebral column)
gap between vertebra and spinal dura mater
spinal extradural space
features of arachnoid mater
elastic, spider-like projections
features of pia mater
innermost, thin, delicate
where do inner and outer meningeal layers of dura mater separate
down longitudinal fissure and at back to form shelf, with occipital lobe above and cerebellum below (tentorium cerebelli); around intracranial venous structures e.g. superior sagittal sinus (outer layer remains superior next to skull, inner is inferior to venous structure)
what is the name of the dural fold following the joining of the bilateral inner layers of dura mater, which join again medially inferior to the superior sagittal sinus
dural partition (falx cerebri)
6 locations of dural folds
tentorial notch, tentorium cerebelli, falx cerebri, infundibulum, diaphragma sellae, falx cerebeli
what layer is CSF present in
subarachnoid space all across CNS
where is CSF produced
choroid plexus in lateral, third and fourth ventricles
where is CSF absorbed
across arachnoid villi (arachnoid granulations at top of brain) into venous circulation
2 functions of dural folds
help stop movement of brain, and provide spaces where blood can drain back into venous system
