The Brain, Meninges + CSF

Question 1

What is the CNS covered by

Answer 1

Meninges: a layer of tissue physically separates the CNS from the rest of the body

Question 2

3 layers that comprise the meninges

Answer 2

• Pia mater: adherent to the brain + dips down into the sulci
• Arachnoid mater: middle layer
• Dura mater: outermost + very tough layer

Question 3

What is the CNS bathed in

Answer 3

The meninges bathe the CNS in Cerebro-Spinal Fluid (CSF)

Question 4

Function of meninges + CSF

Answer 4

Cushions the brain + protects it from damage

Question 5

What is the CSF produced by

Answer 5

Choroid plexus (special epithelium) lining the brain cavities

Question 6

What are the properties of the blood plasma components secreted by the choroid plexus

Answer 6

• Lower in: proteins, cells + most ions than plasma

- Higher concentration of: sodium, chloride + magnesium ions

Question 7

Where does the CSF circulate

Answer 7

Circulates through the ventricles within the brain before exiting onto the surface of the brain to bathe the brain + spinal cord

Question 8

Where is the CSF reabsorbed

Answer 8

Reabsorbed at arachnoid granulations into the the venous circulation

Question 9

What are ventricles

Answer 9

• Spaces or cavities within the brain

- Linked by aqueducts (passageways)

Question 10

Function of ventricles

Answer 10

Allow CSF to circulate through the brain: on to the surface of the CNS or into the spinal cord