Metabolism Of Brain

Question 1

T/F mature neurons do not divide

Answer 1

T

Question 2

Blood brain barrier

Answer 2

. Capillaries highly control movement of materials into and out of brain
. Have specific transport systems
. Requires many transporters, mitochondria to generate ATP to directly or indirectly support transport

Question 3

Carb metabolism in fed brain

Answer 3

. Glucose is almost all energy used in brain
. Glucose obtained from blood and aerobically utilized
. 2 minute supply of glycogen in brain
. Glucose transport independent of insulin

Question 4

Protein metabolism in fed brain

Answer 4

. Needs contestant supply of AA for synthesis of neurotransmitters and protein turnover

Question 5

Fat metabolism in fed brain

Answer 5

. Can’t use FAs, only ketones

. 50% dry weight of brain is FAs mostly in myelin

Question 6

Myelin

Answer 6

. Electrical insulator around axons

. 75-80% lipids and 25% protein

Question 7

Nucleotide metabolism in fed brain

Answer 7

. Brains depends on purine salvage

Question 8

Carb metabolism in starved brain

Answer 8

. Uses glucose oxidation for ATP

. Other tissues catabolize proteins w/ substrates for gluconeogenesis for brain

Question 9

Protein metabolism in starved brain

Answer 9

. Uses AAs for neurotransmitters and protein maintenance

. Uses AAs to small degree as fuel source

Question 10

Fat metabolism in starved brain

Answer 10

. Liver generates ketones

. Uses these by converting them back into acetyl CoA and using them in TCA cycle

Question 11

Nucleotide metabolism in starved brain

Answer 11

. Needs remain even during starvation

Question 12

Lack of oxygen to the brain can cause loss of consciousness in ___

Answer 12

5-10 seconds (other tissues are half an hour w/o O2)

Question 13

Occlusive strokes

Answer 13

Due to closure of blood vessel

Question 14

Hemorrhagic strokes

Answer 14

. Due to bleeding from vessel

Question 15

Ischemia

Answer 15

. Insufficient blood supply
. Does not equal anoxia, it is just reduced blood supply that deprives tissues of O2 but also glucose
. Prevents removal of waste