Module 20: Blood Supply to the Brain, Meninges, Ventricles, and CSF

vertebral arteries

Branch off the subclavian arteries

circle of Willis

confluence of arteries that can maintain perfusion of the brain even if narrowing or a blockage limits flow through one part

basilar artery

what do the vertebral arteries merge into

right and left posterior cerebral arteries

what does the basilar artery divide into

occipital lobe and inferior posterior temporal lobe

what do the posterior cerebral arteries supply

right and left internal carotid arteries

branch off the right and left common carotid arteries

anterior and middle cerebral arteries

what does the internal carotid artery branch into

anterior cerebral artery

supplies blood to the anterior, medial, and superior front lobe

middle cerebral artery

supplies blood to the posterior frontal lobe, most of the temporal and parietal lobes

anterior communicating artery

anastomosis made by the right and left anterior cerebral arteries joining

left and right posterior communicating artery

what forms the posterior arterial circle

initial anterior cerebral arteries and anterior communicating artery

what forms the anterior arterial circle

superior sagittal sinus

absorbs CSF from the meninges

median longitudinal fissure

where does the superior sagittal sinus run

inferior sagittal sinus

in inferior aspect of fall cerebri within medial longitudinal fissure

straight sinus

what does the inferior sagittal sinus drain into

meninges

connective tissue membranes that covers the outer surface of the CNS

dura mater-arachnoid mater-pia mater

give the 3 layers of the meninges from outer-inner

inferior sagittal sinus-straight sinus+superior sagittal sinus-confluence of sinuses-transverse sinuses-sigmoid sinuses-jugular veins

give the pathway of veins starting with the inferior sagittal sinus

dura mater

encloses entire CNS and major blood vessels

periosteal+meningeal

what are the two layers of the dura mater

periosteal layer

directly attached to the inner surface of the bones of the cranium

meningeal layer

adjacent to the middle layer of the meninges

dural reflection

infoldings of the dura that fit into large crevasses of the brain

falx cerebri and falx cerebelli

what are the two dural refections that go through the midline separation of the cerebrum and cerebellum

falx cerebri

infolding between the medial longitudinal fissure

falx cerebrelli

infolding between the right and left hemispheres of the cerebellum

tentorium cerebelli

shelf-like structure between the occipital lobes of the cerebrum and cerebellum

arachnoid trabeculae

thin, filamentous mesh that is below the arachnoid mater

cerebrospinal fluid

what is the subarachnoid space filled with

arachnoid granulations

part of the arachnoid that drains into the dural sinuses

ventricles

open spaces within the brain where CSF circulates

choroid plexus

structure that houses ependymal cells and capillaries

ependymal cells

filter blood into CSF

lateral ventricles

ventricles deep within each hemisphere

septum pellucidum

thin two-layered membrane that separates the lateral ventricles

inventricular foramina

connects the lateral ventricles to the third ventricle

third ventricle

in the space between the left and right diencephalon

cerebral aqueduct

the left and right diencephalon opens into this to pass through the midbrain

fourth ventricle

space between the cerebellum and upper medulla

median aperture and lateral apertures

connect to the subarachnoid space so that CSF can leave the four ventricles