Blood brain Barrier

Question 1

What is the blood supply to the brain?

Answer 1

Brain receives 15-20% of the body’s blood supply.

nutrients and oxygen are carried to brain via blood vessels.

Question 2

What is the blood brain barrier?

Answer 2

A semi permeable barrier between blood and the brain. In most parts of the body the smallest blood vessels known as capillaries are lined with endothelial cells. small spaces between these endothelial cells allow substances to move freely between capillary walls.
But in the brain there are no spaces so substances cannot pass capillary wall and this is known as the BBB
BBB composed of endothelial cells and adrocytic end feet

Question 3

FUNCTIONS of the BBB

Answer 3

• protects brain from foreign substances
• protects brain from hormones and neurotransmitters
• maintains a constant environment for brain