Chapter 6 Study Questions (Part 1) Flashcards
what is the relationship between the hypothalamus and the posterior pituitary?
ADH and oxytocin are created in the hypothalamus,
then sent to and stored in the posterior pituitary
why is the pituitary gland not technically a gland?
it doesn’t make hormones, instead it stores them/is an extension of neural tissue from the hypothalamus
what is a portal system?
when the capillary bed of one gland drains straight into another
how does a portal system facilitate hormone action by the hypothalamus?
allows hypothalamic hormones from being sent/degraded/diluted in general circulation, so they have a faster, stronger, more potent dose to the target tissue
how is your body able to use the hypothalamus and osmoreceptors to monitor dehydration?
aka, how does an osmoreceptor react in a hyperosmolar environment?
hyperosmolar environment = high solute outside
water goes out –> distorts the cell surface and mechanoreceptors –> Na+ comes in –> sends the signal to the brain
why does your body use the hypothalamus and osmoreceptors to monitor dehydration?
wants to monitor the rest of the body through the plasma
how is your body able to use the hypothalamus and osmoreceptors to monitor dehydration?
aka, how does an osmoreceptor react in a hypoosmolar environment?
hypoosmolar = low solute outside
water rushes into the cell –> swelling, headache, etc.
hyperosmolar environment = ?
high solute outside
hypoosmolar environment = ?
low solute outside
how does thyroid hormone affect glycolysis? (2)
TH activates breakdown of glycogen
glucose is released, so you can do glycolysis
increase the heat by making UCP
ADP stimulates PFK
- increases ATP, which increases the ADP&/ATP ratios
- AMP & ADP stimulate PFK to stimulate glycolysis
how does thyroid hormone affect B-oxidation? (2)
- upregulates CPT1 to increase fatty acid metabolism
- longer fatty acid chains are brought in by CPT1 where one acetyl group is clipped off at a time
how does thyroid hormone affect gluconeogenesis? (2)
- AMP stimulates glycogen phosphorylase to release glucose-1-phosphate from glycogen to promote gluconeogenesis
- we do this in the middle of the night to maintain blood glucose levels
what does T3 do to Na+/K+ ATPase pump numbers? why is that significant?
T3 increases Na+/K+ ATPase pump numbers.
increasing ATPase pumps drains ATP levels.
increase in AMP/ATP ratio tells the cell to make more energy
thus, glycolysis and B-oxidation increases
what’s the significance of the AMP/ATP ratio?
1) all cells must maintain a high ratio of cellular ATP:ADP to survive.
2) because of the adenylate kinase reaction (2ADP ↔ ATP + AMP), AMP rises whenever the ATP:ADP ratio falls, and
3) a high cellular ratio of AMP:ATP is a signal that the energy status of the cell is compromised.
how does AMP stimulate PFK to speed up glycolysis?
