Lecture 6 (Part 2)

Question 1

Blood supply to the brain is about…

Answer 1

750ml/min or 50ml of blood/min/100g (steady supply)

Question 2

Blood-brain barrier (BBB):

Answer 2

prevents the access of lipid soluble molecules to the brain, thus it essentially relies on glucose for its energy supply

Question 3

why does very little anaerobic metabolism take place in the brain

Answer 3

Glucose is mostly oxidized in the brain with just a small portion being released as lactate

therefore, the brain has relatively high rates of O2 consumption and CO2 production

Question 4

Under prolonged starvation, the brain adapts to use what as energy

Answer 4

ketones (fat oxidation)

Question 5

How does the brain use ketone bodies as an energy substrate during prolonged fasting or starvation

Answer 5

Fat that comes from adipose tissue enters the blood and goes to the liver which breaks it down, and some of it is converted into ketones

Ketones are a smaller molecule that can pass through the BBB and serve as the energy source