Calcium Regulation and Pharmacology Flashcards Preview

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Flashcards in Calcium Regulation and Pharmacology Deck (66)
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1

What is calcium?

- major EXTRACELLULAR divalent cation (Ca2+)
- 45% ionized Ca2+ exerts physiologic effects

2

Where is 99% of calcium stored?

- in BONE

3

How do we get calcium?

- in the diet.

4

Do men have more calcium than women?

- YES by a little bit.

5

*** For what is calcium needed?

- neuronal excitability
- neurotransmitter release
- cardiac function (PHASE 2 of cardiac action potential as calcium enters).
- muscle contractions
- membrane integrity
- blood coagulation

6

Does calcium use a second messenger system?

- YES

7

What does endocrine regulation of extracellular calcium affect?

- entry at the intestines
- secretion/reabsorption at the kidney
- storage/release (bone absorption/release of Ca2+)

8

What regulates calcium absorption/excretion?

- kidneys and bones

9

What are osteoCLASTS?

- break down (reabsorb) bone to INCREASE serum calcium

10

What are osteoBLASTS?

- build up bone thus DECREASING serum calcium

11

How is calcium absorbed?

- ACTIVE vit. D-dependent transport in PROXIMAL DUODENUM.
- FACILITATED DIFFUSION in small intestines
- efficiency is inversely related to Ca2+ intake.

12

Does calcium intestinal absorption increase or decrease with age?

- decrease

13

Is vitamin D a fat or water-soluble vitamin?

- FAT-soluble.
*remember A, D, E, and K are fat soluble.

14

What happens to the QT with HYPOcalcemia?

- WIDENS the QT

15

What happens to the QT with HYPERcalcemia?

- NARROWS the QT

16

What depresses intestinal calcium transport?

- glucocorticoids
- phenytoin (used for seizures)

17

What do disease states do to calcium?

- lead to fecal loss of calcium

18

What regulates urinary excretion of Ca2+?

- PARATHYROID HORMONE (PTH)
*urinary calcium loss is influenced by filtered Na2+ and presence of non-reabsorbed anions.

19

Can lactation and sweat affect loss of calcium?

- YES

20

Can some diuretics increase urinary loss of Ca2+?

- YES, furosimide
*thiazides will reabsorb calcium!

21

How often is your entire bone mass modified?

every 6 months via osteoclasts and osteoblasts

22

What regulates blood calcium levels?

- PARATHYROID hormone by regulating osteoclasts and osteoblasts.

23

What factors influence bone remodeling?

INCREASE in the activation of remodeling units:
- hyperthyroidism
- hypervitaminosis D
- hyperparathyroidism

24

What is the etiology of impaired osteoBLASTIC function?

- high dose CORTICOSTEROIDS
- high dose ETHANOL

25

What will augment osteoCLASTIC resorptive capacity?

- decreased estrogen

26

What promotes HYPOcalcemia?

- deprivation of Ca2+ and vitamin D

27

What stimulates PTH release?

- HYPOcalcemia

28

What are the signs of symptoms of HYPOcalcemia?

- tetany
- paresthesias
- increased neuromuscular excitability
- laryngospasm
- muscle cramps
- tonic-clonic convulsions (GRAND MAL)

29

If a patient is having a seizure what should you not forget to check?

- CALCIUM

30

What are some hypocalcemic states?

- hypoparathyroidism
- advance renal insufficiency
- excessive use of K+ phosphate in the tx of DKA
- sodium fluoride (large quantities)
- massive transfusions with CITRATED BLOOD.