Calcium Physiology Flashcards
What players raise serum calcium?
PTH, calcitriol, bone resorption, renal retention
What players decrease serum calcium?
Hyperphosphatemia, lack of PTH/calcitriol/bone resorption/renal retention
What causes an increase in phosphate?
Calcitriol
What causes a decrease in phosphate?
PTH, renal losses
What are the main actions of PTH?
Raise calcium and lower PO4
What causes an increase in PTH?
Hypocalcemia, hyperphosphatemia
What causes a decrease in PTH?
Hypercalcemia, calcitriol
What is the action of calcitriol?
Raise calcium and PO4
What causes an increase in calcitriol?
PTH, hypophosphatemia
What causes a decrease in calcitriol?
Low PTH, renal failure
What is the action of 1-alpha-hydroxylase?
Make calcitriol
What increases 1-alpha-hydroxylase?
PTH, hypophosphatemia
What decreases 1-alpha-hydroxylase?
Low PTH, renal failure
What is calcidiol?
Substrate for calcitriol
What increases calcidiol?
Diet/sun exposure
Jeb, a healthy 24 year old med student has had trouble with the endocrine exam. He asks Dr. Kline if he can get some extra endocrine exposure prior to the rewrite, so Dr. Kline sets up the following “exposure”. Jeb gets an intravenous infusion of calcium at a fairly high dose. Before becoming confused and combative, Dr. Kline asks the following questions: After 30 minutes of the infusion, what will happen to serum PTH?
A) Increase
B) Decrease
C) No change
B) Decrease
Jeb, a healthy 24 year old med student has had trouble with the endocrine exam. He asks Dr. Kline if he can get some extra endocrine exposure prior to the rewrite, so Dr. Kline sets up the following “exposure”. Jeb gets an intravenous infusion of calcium at a fairly high dose. Before becoming confused and combative, Dr. Kline asks the following questions: After 30 minutes of the infusion, what will happen to urine calcium?
A) Increase
B) Decrease
C) No change
A) Increase
Jeb, a healthy 24 year old med student has had trouble with the endocrine exam. He asks Dr. Kline if he can get some extra endocrine exposure prior to the rewrite, so Dr. Kline sets up the following “exposure”. Jeb gets an intravenous infusion of calcium at a fairly high dose. Before becoming confused and combative, Dr. Kline asks the following questions: After 30 minutes of the infusion, what will happen to 1-alpha-hydroxylase?
A) Increase
B) Decrease
C) Stay the same
B) Decrease
Jeb, a healthy 24 year old med student has had trouble with the endocrine exam. He asks Dr. Kline if he can get some extra endocrine exposure prior to the rewrite, so Dr. Kline sets up the following “exposure”. Jeb gets an intravenous infusion of calcium at a fairly high dose. Before becoming confused and combative, Dr. Kline asks the following question: If IV calcium is maintained for a few days what will happen to serum 1, 25-vit D?
A) Increase
B) Decrease
C) No change
B) Decrease
Jeb, a healthy 24 year old med student has had trouble with the endocrine exam. He asks Dr. Kline if he can get some extra endocrine exposure prior to the rewrite, so Dr. Kline sets up the following “exposure”. Jeb gets an intravenous infusion of calcium at a fairly high dose. Before becoming confused and combative, Dr. Kline asks the following question: If IV calcium is maintained for a few days what would happen to serum 25-vit D?
A) Increase
B) Decrease
C) No change
C) No change
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s serum calcium?
Increase
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s serum phosphate?
Decrease
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s urine phosphate?
Increase - PTH promotes renal phosphate wasting.
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s serum 1,25 dihydroxyvitamin D?
Increase; PTH stimulates 1-alpha-hydroxylase. Hypophosphatemia also stimulates this process.
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s absorption of ingested calcium?
Increase; this is due to increase calcitriol.
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s number of bone multicellular units becoming active?
Increase in bone remodelling units
Jeb was so pleased with his first experience, he allowed Dr. Kline to surgically connect his circulation with that of a mouse that has a PTH producing tumour. Before the onset of a fairly severe acute hemolytic crisis (for which Dr. Kline loses points on his faculty evaluation), what would happen to Jeb’s bone resorption?
Increase; therefore osteoporosis results in people who have PTH secreting tumours.
