Cerebrospinal Fluid

Question 1

What is cerebrospinal fluid? What is it produced by?

Answer 1

Clear fluid composed mostly of water produced by choroid plexus in the ventricles

Question 2

What are the 3 main functions of CSF?

Answer 2

Mechanical protection (shock absorb)
Homeostasis (pH)
Circulation (medium for gas/nutrient exchange)

Question 3

CSF secretion involves the transport of which ions from blood to CSF?

Answer 3

Na
Cl
HCO3

Question 4

How does the composition of CSF differ from that of plasma?

Answer 4

More Na, Cl

Less K, glucose, protein

Question 5

How are the ventricles of the choroid plexus connected?

Answer 5

Lateral ventricle-3rd ventricle: intraventricular foramina
3rd-4th ventricle: cerebral aqueduct
4th ventricle-subarachnoid space: foramina of magendie
4th ventricle-subarachnoid space: foramina of luschka

Question 6

Describe the flow of CSF from the ventricles to venous blood

Answer 6

CSF formed in lateral ventricle;
flow to 3rd ventricle;
flow to midbrain;
flow to 4th ventricle;
flow to subarachnoid space;
flow to central canal of spinal cord
returns to venous blood through arachnoid granulations into dural venous sinuses

Question 7

What is the blood brain barrier?

Answer 7

Tight junctions between endothelial cells in brain capillaries that protect the brain from infection and toxins and is a barrier to drug delivery