Lecture27: Parathyroid, Calcitonin

Question 1

What are the hormones involved in calcium level regulation?

Answer 1

PTH, Calcitonin, and Calcitriol

Question 2

What does PTH do to calcium levels?

Answer 2

Increases it

Question 3

What does PTH act on, target organs?

Answer 3

Bone, kidneys and intestines

Question 4

How does PTH increase bone resporption and calcium mobilization?

Answer 4

It increases osteoclastic activity and proliferation

Question 5

Which vitamin increases calcium absorption from intestine?

Answer 5

Vitamin D3

Question 6

How is PTH secretion regulated?

Answer 6

Via calcium levels, low calcium means high PTH secretion

Question 7

Do high phosphate concentrations stimulate PTH secretion?

Answer 7

Yes

Question 8

does Calcitriol inhibit PTH secretion?

Answer 8

Yes

Question 9

Hypoparathyroidism leads to?

Answer 9

Tetany, hypocalcemia

Question 10

What is Tetany?

Answer 10

Muscle spacticity caused by decreased calcium levels

Question 11

Causes of Tetany?

Answer 11

Hypocalcemia, hypoparathyroidism, vit D deficiency

Question 12

What’s a carpopedal spasm?

Answer 12

Spontaneous contraction in the muscles of the extremities

Question 13

What is Latent Tetany?

Answer 13

It needs test to provoke the spasms, like Chovostek’s sign

Question 14

Carpopedal spams occur also in which muscles?

Answer 14

Respiratory muscles

Question 15

How to Test for Latent Tetany?

Answer 15

Chovostek’s sign and Trousseau’s sign

Question 16

Hyperparathyroidism leads to bone fractures and cysts how?

Answer 16

The increased bone resorption makes it de-calcified

Question 17

Most common complication of increased bone resorption is?

Answer 17

Ostitis Fibrosa Cystica

Question 18

What are the effects of hypercalcemia?

Answer 18

Muscular weakness, pain, constipation, RENAL STONES

Question 19

What are the effects of Calcitriol on the intestine?

Answer 19

Increases both calcium facilitated diffusion and active transport

Question 20

How is Calcitriol synthesis regulated?

Answer 20

Negative feedback, low calcium increases Calcitriol synthesis

Question 21

Name 2 functions of Calcitonin?

Answer 21

Reduces bone resporption and increases calcium secretion

Question 22

How is Calcitonin regulated?

Answer 22

When calcium increases, calcitonin increases. Positive feedback