Brain Protection Flashcards
What are the FOUR structures that protect the brain?
The skull, cerebrospinal fluid, the meninges, and the blood-brain barrier.
What are the structural features of the skull that protect the brain?
Very thick and contains holes for structures contained within the brain. Holds the brain in place.
How do the meninges protect the brain?
They keep the brain intact.
What are the THREE meninges?
The dura mater (outside layer), arachnoid mater (inferior to dura mater), and the pia mater (thin tissue layer following groves and ridges of the brain).
What is the role of cerebrospinal fluid/CSF?
The CSF acts as a shock absorber and keeps the brain still.
What percentage of CSF makes up the brain’s weight?
97%.
What produces CSF?
The choroid plexus (blood vessels).
Where is CSF produced?
Within the ventricles.
What are ventricles?
Hollow spaces that are filled with fluid.
Describe the CSF pathway?
Lateral ventricle - > third ventricle - > fourth ventricle - > brain - > spinal cord.
How much CSF (in mL) is produced in the average adult?
150mL.
How often is CSF replaced?
Every 8 hours.
What is the blood-brain barrier?
The barrier between the blood and the brain.
What is the purpose of the blood-brain barrier?
Allows some substances (i.e. fat-soluble) across the brain, and prevents others (i.e. larger molecules such as WBC).
What structures are exempt from the blood-brain barrier and what instance are they activated?
The hypothalamus and pituitary gland are exempt; they are activated when there is a leaky barrier.
