Week 3 - Supporting the Brain Flashcards
(22 cards)
What are the three meningeal layers in the CNS?
Dura mater, Arachnoid membrane, Pia mater.
Which meningeal layer is missing in the PNS?
Arachnoid membrane.
What is the subarachnoid space?
Fluid-filled space between arachnoid and pia mater; cushions the brain.
How many brain ventricles are there?
Four: two lateral, third, and fourth ventricles.
Where is CSF first produced?
Choroid plexus of lateral ventricles.
Where is the lateral ventricle located?
In the telencephalon.
What are the four vital functions of CSF?
Protection, buoyancy, waste reduction, transport.
What is hydrocephalus?
CSF accumulation in ventricles causing dilation.
What is obstructive hydrocephalus?
Hydrocephalus caused by a blockage.
What are the main types of glial cells?
Astrocytes, microglia, oligodendrocytes, Schwann cells.
Where are Schwann cells found?
In the PNS.
Where are oligodendrocytes found?
In the CNS.
What do Schwann cells and oligodendrocytes do?
Form the myelin sheath around axons.
What are the functions of astrocytes?
Support neurons, regulate extracellular fluid, isolate synapses, nutrient transfer, phagocytosis.
How are astrocytes involved in ALS?
Lose neuroprotective roles and become toxic; target for therapy.
What is the role of microglia?
Immune cells in CNS; phagocytosis, inflammatory response, protect against pathogens.
How much of the body’s blood supply goes to the brain?
15–20%.
What are the functions of blood for the brain?
Delivers oxygen, nutrients, hormones; removes CO2, ammonia, lactate.
What forms the BBB?
Tight junctions between endothelial cells in brain capillaries.
What are the functions of the BBB?
Protect from harmful substances, hormones, and maintain brain environment.
What substances cross the BBB easily?
Lipid-soluble molecules.
How do water-soluble molecules cross the BBB?
Via carrier-mediated transport or active transport.
