Calcium Homeostasis Flashcards Preview

2MB Endocrinology > Calcium Homeostasis > Flashcards

Flashcards in Calcium Homeostasis Deck (9)
Loading flashcards...
1

Calcium homeostasis refers to regulation of Ca ions in the ICF. True/False?

False
ECF

2

What effect does hypocalcaemia have on voltage-activated Ca channels?

Opens them, causing hyperactive nerve and muscle conduction (hypocalcaemic tetany)

3

In hypercalcaemia, calcium ions can combine with phosphate ions to form what?

Calcium phosphate (no shit) "stones" that deposit in blood and kidneys

4

Which glands secrete the hormone responsible for controlling Ca concentration in the body?

Parathyroid glands
(secrete PTH)

5

What effect does PTH have on the kidney with regards to Ca homeostasis?

Increases Ca reabsorption
Increases phosphate excretion
Stimulate release of calcitriol (vitamin D)

6

What effect does PTH have on bone with regards to Ca homeostasis?

Increases Ca pumping into ECF
Increases bone resorption

7

Which receptors on parathyroid cells are activated in hypocalcaemia?

CaSR (calcium-sensing-receptors)

8

What effect does calcitriol (active vitamin D) have on the gut with regards to Ca homeostasis?

Increases Ca absorption

9

Where is the hormone calcitonin produced from?
What is its effect?

C cells of the thyroid (parafollicular cells)
Opposes effects of PTH