CNS 1 Flashcards
Neurovascular Unit
a functional unit composed of groups of neurons and their associated astrocytes, interacting with smooth muscle cells and endothelial cells on the arterioles responsible for their blood supply and capable of regulating the local blood flow
Choroid Plexus
a site of production of CSF in the adult brain, it is formed by the invagination of ependymal cells into the ventricles, which become richly vascularized
Interstitial Fluid
The extracellular fluid filling the interstices of the tissue and bathing the cells
Meninges
The complex arrangement of 3 protective membranes surrounding the brain with a thick outer connective tissue layer (dura) overlaying the barrier layer (arachnoid), and finally the thin layer covering the glia limitans (pia)
Protection mechanisms of the brain
the bones of the cranium, the cranial meninges, CSF
What is the most outer layer of the meninges? (and describe)
dura mater: two fibrous layers space between the 2 layers contains tissue fluids, blood vessels and lymphatic system
What is the middle layer of the meninges? (and describe)
arachniod membrane; epithelial layer, does not follow the brain’s underlying folds
where is CSF stored?
the subarachnoid space
What is the inner most layer of the meninges
the pia mater; following the brain’s underlying folds, accompanies the branches of cerebral blood vessels
How does the brain meet dynamic metabolic needs?
Oxygen passes freely across the BBB and glucose requires membrane transporters (astrocytes contribute through lactate)
When does the brain use ketone bodies?
development and starvation
Major Arteries of the Brain
Internal Carotid Arteries, Vertebral Arteries
Major veins of the brain
Internal Jugular Veins
What is the significance of the Circle of Willis
collateral circulation; helpful if there is a blockage in one of the artieries
What is the brain interstitial system
space among neural cells and capillaries; contains: interstitial fluid, extracellular matrix
