Calcium Homeostasis

Question 1

true or false: calcium homeostasis refers to the regulation of calcium ions in the ICF

Answer 1

false

in the ECF

Question 2

what effect does hypocalcemia have on voltage activated calcium channels?

Answer 2

opens them

causing hyperactive nerve and muscle conduction

Question 3

in hypercalcemia, calcium ions combine with phosphate ions to form what?

Answer 3

calcium phosphate stones that deposit in the blood and kidneys

Question 4

which glands secrete the hormone responsible for controlling calcium concentration in the body?

Answer 4

parathyroid glands (secrete PTH)

Question 5

what effect does PTH have on the kidney with regards to calcium homeostasis?

Answer 5

increases Ca reabsorption
increases phosphate excretion
stimulates release of calcitriol

Question 6

what effect does PTH have on bone with regards to calcium homeostasis?

Answer 6

increases calcium pumping into ECF

increases bone resorption

Question 7

which receptors on parathyroid cells are activated in hypocalcemia?

Answer 7

CaSR

calcium sensing receptors

Question 8

what effect does calcitriol have on the gut with regards to calcium homeostasis?

Answer 8

increases calcium absorption

Question 9

where is the hormone calcitonin produced?

Answer 9

C cells of the thyroid

Question 10

what is the effect of calcitonin?

Answer 10

opposes the effect of PTH