new_n_lost
Forum Hero
Topics: 663
Posts: 6,107
|
Which of the following statements is/are true regarding PTH?
A) Secretion is stimulated by hypocalcemia.
B) Secretion is inhibited by hypercalcemia.
C) The effect of magnesium on secretion is the same as that of calcium.
D) Secretion is stimulated by low 1,25-hydroxyvitamin D and inhibited by high levels of 1,25-hydroxyvitamin D.
E) A, B, and D
F) All of the above
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| Luckyall
Forum Guru
Topics: 11
Posts: 593
|
E EEEEEEEeeeeeeee
Edited by Luckyall on 03/25/07 - 08:47 PM
|
| rock
Forum Elite
Topics: 23
Posts: 305
|
E
|
| new_n_lost
Forum Hero
Topics: 663
Posts: 6,107
|
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| new_n_lost
Forum Hero
Topics: 663
Posts: 6,107
|
Answer: E
Explanation: PTH, an 84-amino-acid peptide synthesized and secreted by the parathyroid gland, is a potent regulator of the serum calcium level. Hypocalcemia stimulates the secretion of PTH acutely (with increased PTH synthesis and parathyroid cell hypertrophy and hyperplasia after chronic hypocalcemia), whereas hypercalcemia leads to decreased secretion of PTH. Hypomagnesaemia inhibits PTH secretion. Elevated 1, 25-dihydroxyvitamin D affects PTH synthesis and secretion by directly inhibiting the parathyroid gland and indirectly via hypercalcemia. Low levels of 1, 25-dihydroxyvitamin D have the opposite effect.
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
|
| |
| | | | | |
