05.2 Calcium and Kidney Stones

Question 1

What effects does calcitriol have?

Answer 1

Increased calcium absorption at the intestines.

Question 2

What effect does calcitonin have?

Answer 2

(Not much in humans, more active in pregnancy).
Inhibits calcium absorption by intestines.
Inhibits bone reabsorption.
Inhibits kidney retention of calcium.

Question 3

How do kidney stones form?

Answer 3

Urine becomes supersaturated.
The solute come out of solution and aggregate to form a seed crystal on the renal papilla.
These then break of an travel into the ureter.

Question 4

Where do stones most commonly get stuck?

Answer 4

Where the ureters are narrowest.
Uretopelvic junction.
Pelvic brim.
Entrance to the bladder.

Question 5

What are the effects of PTH?

Answer 5

Resorption of calcium from bone.
Retention of calcium at the kidney.
Calcitriol formation from vitamin D.

Question 6

What very common type of stone can acidic urine cause?

Answer 6

Calcium oxolate

Question 7

What kind of stone can an infection lead to?

Answer 7

Struvite.

Question 8

What kind of stone can alkali urine lead to?

Answer 8

Calcium phosphate

Question 9

What can cause a cystine stone to form?

Answer 9

Homocystinuria