Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
|
What are the two things required for brian function?
|
glucose
oxygen |
|
|
What is rate limiting step in glycolysis?
|
hexokinase and G6P
|
|
|
After G6P is made what hapepns to it?
|
1)it can go through glycolysis
2)it can become glycogen 3) it can enter the pentose shunt |
|
|
Where does most og G6P end up going?
|
90% to glyclolysis, 5% to glycogen, 5% to pentose shunt
|
|
|
What is the rate limiting enzyme in the TCA cycle
|
pyruvate dehydrogenase
|
|
|
What regulates byruvate dehydrogenase?
|
ATP/ADP and Ca levels
|
|
|
What does the citric acid cycle also produce besides ATP
|
amino acids/neurotransmitters
|
|
|
Does aerobic metabolism of brain use its fair share of oxygen consumed by body?
|
no it uses way more
|
|
|
What is the relationship between astrocytes and neurons in terms of lactate shuttle?
|
1)astrocytes take up glucose by facilitated diffusion and convert it to lactate
3)lactate goes into neurons 4) lactate goes back to pyruvate and goes to TCA cycle |
|
|
what stores most of glygocen in brain?
|
astrocytes
|
|
|
What is the link between increased activity and astrocytes?
|
1)increased neuronal activity means more glutamate
2) glutamate taking up by astrocytes and converted to glutamine 3)glutamine stimulates Na/K ATPase 4) glycolysis in astrocytes is driven forward |
|
|
What are teh changes during the prenatal period?
|
becomes ketotic at birth in response to high fat in moms milk and brain is hypoglycemic
|
|
|
What are changes in child hood?
|
different rates for different parts of brain going
|
|
|
What are the age related differences in blood flow and oxygen consumption between 21 and 71
|
no difference
|
|
|
What are age related diseases that can cause metabolic disruption?
|
vasculature and neurodegenerative diseases such as ateriosclerosis and snile psychosis
|
|
|
What happens to the brain in hypoglycemia?
|
confusion or lack of consciousness
|
|
|
What causes hypoglycemia in brain?
|
usually hyperinsuliemia
|
|
|
What are conditions that present with hyperglycemia?
|
1)liver failure
2) fatty acid oxidation deficiency and fasting 3) genetic abnormalities of glucose transport in BBB |
|
|
What is ischemia caused by?
|
1) stroke
2) trauma 3) edema 4) cardiac arrest |
|
|
What is the mechanism of ischemia?
|
1)loss of ATP production
2) ion pumps fail 3) cell depolarized 4) Ca channels open 5) Ca activates proteases for cell death |
|
|
What are effects of hypoxia/ischemia on nearby tissues?
|
1)accumulated lactate causes tissue acidosis
2)spreading depression 3)excitotoxicity |
|
|
What is spreading toxcicity?
|
dying neurons release K into ECM which depolarizes neurons outside the effected area
|
|
|
How does excitotoxicity happen in ischemia?
|
excess glutamate activates NMDA receptors and opens Ca channels in adjacent tissues
|
|
|
What are the regions of brain susceptable to ischemia?
|
1)hippocampus Ca1
2)frontal corrtex 3) amygdyla 4) straitum 5) thalamus |
|
|
What is an effective treatment?
|
tissue plasminogen activating factor
|
|
|
What is the problem with reperfusion treatment
|
it does not always work because of vasospasm etc
|
