Parathyroid and Adrenal Flashcards Preview

Dr Campbell EXAM 3 > Parathyroid and Adrenal > Flashcards

Flashcards in Parathyroid and Adrenal Deck (20):
1

normal levels of calcium in blood

9-10 mg/dl

2

Calcium distribution

40% combined with plasma proteins
10% bound to low-molecular weight substances (citrate or phosphate)
50% ionized

3

Chief cells

Most numerous paranchymal cells of the parathyroid. They secrete PTH

4

Oxyphil cells

These are a minor cell type in parathyroid glands.
They are not secretory and increase in number with age

5

What is the relationship of Vitamin D and Calcium?

Vitamin D is important for the absorption of calcium from the intestinal tract

6

This results when there is a decline in plasma calcium levels

Hypocalcemia

7

Lethal if calcium levels fall below

4 mg/dl

8

Hypercalcemia: when levels are approximately 12 mg/dl

Causes depression of nervous system, constipation and lack of appetite

9

When levels are as high as 17 mg/dl, what happens to calcium phosphate crystals

Calcium phosphate crystals precipitate throughout the body

10

Calcitonin

lowers serum calcium

11

Function of PTH

Regulates calcium and phosphate levels in the blood:
Causes release of calcium and phosphate from the calcified bone matrix (bone resorption).
Reduces excretion of calcium by the kidneys.
Increases phosphate excretion by the kidneys.
Increases absorption of calcium from the intestine.

These effects cause blood calcium levels to increase but blood phosphate levels to decrease

12

Hypoparathyroidism

This condition leads to inactivation of osteoclasts: calcium reabsorption is decreased leading to hypocalcemia

13

Treatment for hypoparathyroidism

Vitamin D and its analogs

14

Hyperparathyroidism

Usually due to a tumor of the parathyroid glands. Causes extreme osteoclastic activity in bones. In severe cases, bone may be entirely eaten away.

15

Mild parathyroidism can cause formation of

Kidney stones

16

Regulated by a simple feedback system. When calcium levels are low

PTH is secreted

17

Treatment
Cinacalcet:

calcimimetic drug= reduces PTH secretion by influencing the parathyroid calcium sensing receptors

18

Treatment of osteoporosis

Adequate intake of calcium and vitamin D
Bisphosphonates: alendronate, risedronate, ibandronate, zoledronic acid
PTH fragment: anabolic (bone building) compound when used intermittently
calcitonin: Inhibits osteoclasts and increases bone mass
Estrogen/Hormone Therapy (ET/HT)

19

total loss of aldosterone

leads to death within 3 days to 2 weeks

20

Hyperadrenalism (Cushing's disease)

Caused by cortisol secreting tumor or hyperplasia of adrenal cortex due to increased secretion of ACTH