Ch 7 Calcium homeostasis

Question 1

Three hormones that regulate calcium

Answer 1

1. Calcitriol
2. Calcitonin
   3. Parathyroid hormone PTH

Question 2

Where is calcitriol produced?

Answer 2

Skin, liver, kidneys

Question 3

Why is calcitriol secreted?

Answer 3

Hypocalcemia; blood calcium to low

Question 4

Function of calcitriol

Answer 4

To raise blood calcium by increasing activity of osteoclasts to get more calcium into blood

Question 5

Calcitonin Produced where?

Answer 5

Thyroid gland

Question 6

Why is calcitonin secreted?

Answer 6

Hypercalcemia; blood calcium too high

Question 7

Function of calcitonin

Answer 7

To lower blood calcium by inhibiting osteoclast and stimulating osteoblast

Question 8

Parathyroid hormone PTH is produced where?

Answer 8

Parathyroid gland

Question 9

PTH is secreted because…

Answer 9

Hypocalcemia; blood calcium is too low

Question 10

Function of PTh?

Answer 10

Raise blood calcium by
-increasing osteoclast,
-decreasing osteoblast,
-increasing urinary phosphate excretion,
-decreasing urinary calcium excretion

Question 11

Calcium homeostasis is determined by:

Answer 11

1. Dietary intake
2. Digestive excretions
   3. Osseous tissue exchange

Question 12

Calcium is needed for:

Answer 12

-Bones
-neuron communication
-muscle contractions
-blood clotting
-Exocytosis

Question 13

Hypocalcemia is caused by:

Answer 13

– Vitamin D deficiency
– diarrhea
– thyroid tumors
– pregnancy

Question 14

Hypercalcemia Can cause:

Answer 14

Suppression of nervous system; complete suppression equals arrest

Question 15

Phosphate homeostasis is important for:

Answer 15

DNA/RNA/ATP

Question 16

Which hormone raises phosphate levels and how?

Answer 16

Calcitriol, by small intestine reabsorption.

Question 17

Which hormone lowers phosphate levels and how?

Answer 17

Parathyroid hormone PTh; Through urinary excretion (kidneys)