1-3 meninges, ventricles, & blood supply Flashcards
(35 cards)
meninges
protection & nourishment of the brain
hold structures in place during movement
mechanical suspension
flotation (CSF)
support & separation for structures
dura mater
tough, fibrous white layer
closest to the skull
2 layers - periosteal & meningeal
falx cerebri
dural reflection penetrating the cerebral hemispheres
tentorium cerebelli
dural reflection between the occipital lobe & cerebellum
dural sinus
layers separate & form a channel where cerebral veins can empty
no epidural space - meningeal artery can tear & create epidural bleed (hematoma)
nor subdural space - venous sinus can tear & create subdural bleed (hematoma)
vein can’t empty into sinus because it’s
tearing, floods brain w/ blood
arachnoid
tough but filmy & translucent
closely abuts the dura - no subdural space
separated from pia by subarachnoid space
subarachnoid space
space under arachnoid layer
external arteries & veins run through here - can rupture & cause subarachnoid bleed
arachnoid trabeculae
spider web looking stuff in subarachnoid space
contains CSF
contributes to maintenance of subarachoid space
arachnoid villi
protrusions that poke through the dura into the sinuses where CSF is dumped into venous sinus
pia
very thin & fragile
directly apposed to neural tissue in most places
bottom part of arachnoid
contributes to maintenance of subarachoid space
bacterial meningitis
infection & inflammation of the meninges layers themselves
lateral ventricle
2 lateral ventricles
c-shaped structures
CSF flows from lateral to 3rd through the intraventricular foramen
3rd ventricle
cavity of 3rd ventricle becomes cerebral aqueduct
connects 3rd & 4th ventricles
4th ventricle
3 openings to subarachnoid space
cerebral spinal fluid
clear colorless liquid
produced by choroid plexus
circulates from ventricles into subarachnoid space
active transport of materials & removal of harmful & waste substances
choroid plexus
lines lateral & 4th ventricle
produces CSF
located in the center of the lateral & 4th ventricles
CSF circulation
subarachnoid space wraps around entire CNS
CSF collects in cisterns at the base of the skull
CSF is absorbed through araachnoid villi (one way openings
these structures protrudeinto the dural sinus & empty CSF into superior sagittal sinus
hydrocephalus
“water filled head”
abnormal enlargement of ventricles
increased pressure compresses brain tissue
external carotid
supplies blood to facial muscles, forehead, oral & nasal cavities
internal corotid
internal structures of the brain
carotid joins the circle of willis & divides to form 2 cortical arteries
- anterior cerebral artery
- middle cerebral artery
anterior cerebral
enters the longitudinal fissure
supplies blood to the corpus callosum,, medial aspects of frontal & parietal lobes
2 ACAs connected by anterior commnicating artery
disruption causes:
paralysis to legs & feet
cognitive impairment
middle cerebral
lateral into the lateral sulcus
supplies blood to insula & most of the lateral aspect of the hemispheres
supplies to the pre & post central gyri
disruption causes:
major motor & somatosensory deficits
left hemisphere = language deficits
vertebral arteries
fuse at the junction between medulla & pons to form Basilar A
3 pre-terminal brances
PICA
posterior inferior cerebellar artery
supplies blood to inferior cerebellum