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Flashcards in parathyroid Deck (53):
1

where is 99% is bone in the body?

in bone

2

where is the smallest store of calcium in the body?

extracellular

3

what pool is calcium is the regulated pool?

extracellular calcium

4

where is Ca2+ absorbed?

the gut

5

is Ca2+ excreted?

yes by the kidney

6

how many total parathyroid glands are in most animals?

4 glands (2pairs)

7

what is the main organ of Ca2+ and phosphate metabolism?

parathyroid

8

what are the active cells of the parathyroid?

chief cells

9

what type of hormone is PTH?

peptide hormone

10

what are the inactive cells of the PT?

oxyphil cells

11

what cells synthesize PTH?

chief cells of the PT

12

in the human PTH half life is 7-10 days, how long is it in the dog?

10-15 min

13

what terminus of PTH is the biologically active part?

the N-terminus

14

what stimulates PTH?

low serum calcium

15

PTH counters the actions of what?

calcitonin

16

PTH had direct or indirect effects on bone metabolism of Ca2+?

direct

17

PTH had direct or indirect effects on kidney metabolism of Ca2+?

direct

18

PTH had direct or indirect effects on GI metabolism of Ca2+?

indirect

19

is the response to PTH rapid or slow?

rapid

20

where does the calcium come from in the bone?

hydroxyapatite

21

what is PTH's effect on the kidney?

-increased absorption of calcium by distal tubles
-formation of calcitriol
-excretion of phosphate in the urine

22

what is PTH's effect on the small intestine?

increased absorption of calcium and phosphate
-(consequence of calcitriol from kidney)

23

increased blood calcium and calcitriol in the blood does what to blood phosphorus?

reduces phosphorus in blood via renal excretion

24

what cells produce calcitonin?

parafollicular (C-cells) of the thyroid gland

25

what is the roll of calcitonin?

decrease Ca2+ in the ECF
-moves Ca2+ to bone by blocking osteoclast activity
-inhibits Ca++ absorption by intestines
-inhibits renal tubular cell reabsorption of Ca++

26

what shuts off PTH activity?

increased Ca++ in blood

27

what is hypophosphatemia, caused by calcitonin?

- moves phosphate from ECF to bone
-inhibites phosphate absorption by renal tubules

28

what is calcitriol?

the bioactive from of vitamin D

29

what is the role of calcitriol?

increases CA++ and phosphorus in the blood

30

what results from disturbances of serum levels of Ca++ (increased serum Ca++)?

hyperparathyroidism

31

what are the effects of hyperparathyroidism metabolism on bone?

-increased bone resoprtion
-decreased radiographic density (radiopacity)
-incomplete fractures

32

what are the signs of hyperparathyroidism?

-depressed mentation
-muscular weakness
-peptic ulcers
-lethargy
-renal failure

33

what is calcitonin's effect of blood phosphorus?

decreases it

34

what is PTH's effect of blood phosphorus?

decreases it

35

which type of hyperparathyroidism is more common?

secondary

36

which form of hyperparathyroidism is an adenoma of chief cells?

primary

37

effects of primary hyperparathyroidism on urine/blood Ca++/phosphorus:

-hypercalciuria, hypercalcemia
-hyperphosphaturia, hyophosphatemia

38

what type of hyperparathyroidism is caused by chronic renal failure?

secondary

39

what does renal damage do to calcitriol?

reduces calcitriol synthesis

40

as [phosphorus] increases, what happens to [Ca++]?

[Ca++] decreases

41

secondary hyperparathyroidism do to blood/urine calcium?

normocalcemia and hypocalciuria

42

secondary hyperparathyroidism do to blood/urine phosphorus?

hyperphosphatemia

43

what causes rubber jaw disease?

secondary hyperparathyroidism

44

what type of hyperparathyroidism is causes by nutritional deficiencies and mineral imbalance?

secondary

45

what diets can cause secondary hyperparathyroidism?

low Ca++ and high phosphorus

46

what are two causes of hypoparathyroidism?

- lymphocytic parathydroiditis
-surgery for hyperthyroidism

47

what are the symptoms of hypoparathyroidism?

-hyperflexia
-larygneal spasm
-convultions

48

what is the treatment for acute hypoparathyroidism?

IV calcium gluconate

49

what is the treatment for chronic hypoparathyroidism?

oral calcium carbonate and vit. D
low phosphorus diet

50

where are the sites of synthesis for erythropoietin (EPO)?

-kidney (primary; peritubular cells)
-liver (not in dog)

51

what controls the negative feedback of erythropoietin synthesis/

-hypoxia

52

what site does EPO act on?

red bone marrow

53

what are the actions of erythropoietin?

-increases differentiation of hemocytoblasts into reticulocytes STEM CELL ACTION
-increases synthesis of key proteins
-alpha and beta globins
-transferrin receptor