week 3-tissue mineralization

Question 1

pathologic mineralization is due to

Answer 1

deposition of Ca salts in tissue

Question 2

what does increased levels of Ca in cells cause

Answer 2

devastating results and sometimes irreversible cell injury

Question 3

what is dystrophic mineralization

Answer 3

Ca deposition due to dysregulation at local level

Question 4

what is metastatic mineralization

Answer 4

Ca deposition due to systemic dysregulation

Question 5

animals with dystrophic calcification have _____ blood levels of Ca

Answer 5

normal

Question 6

animals with metastatic mineralization have _____ levels of Ca

Answer 6

high

Question 7

high levels of Ca

Answer 7

hypercalcemia

Question 8

gross appearance:

Answer 8

tissue is white to tan and feels gritty

Question 9

histologic appearance:

Answer 9

H&E stain: granular, deeply basophilic material
Von Kossa stain: brown-black

Question 10

in dystrophic mineralization, how is Ca deposited?

Answer 10

cells that are necrotic/undergoing necrosis cannot regulate cystolic Ca levels and Ca is deposited

Question 11

where is Ca normally absorbed

Answer 11

through the gut

Question 12

where is Ca normally excreted

Answer 12

through the kidneys

Question 13

In between absorption and excretion, normally, Ca _______

Answer 13

moves in between body compartments

Question 14

the bone acts

Answer 14

as a storage depot

Question 15

what happens when blood Ca is high

Answer 15

parafollicular cells inc secretion of calcitonin and parathyroid glands reduce PTH secretion
Ca is deposited

Question 16

what does calcitonin do?

Answer 16

stimulates osteoblasts to remove Ca from blood and deposit it as bone

Question 17

what does PTH do?

Answer 17

cause Ca mobilization from bone
also inhibits Ca loss via urine
also stimulates kidneys to make calcitriol

Question 18

what happens when blood Ca is low

Answer 18

calcitonin secretion dec.
PTH secretion inc.
Ca liberated from bone

Question 19

what does calcitriol do

Answer 19

increases intestinal absorption of Ca and mobilization from bone

Question 20

what does vit D when metabolized

Answer 20

produces active metabolites such as calcidiol

Question 21

what does calcidiol do?

Answer 21

acts on kidney to upregulate calcitriol

Question 22

5 main mechanisms of hypercalcemia

Answer 22

1. primary hyperparathyroidism
2. hypercalcemia of malignancy
3. vit D toxicosis
4. renal failure
5. bone destruction

Question 23

what is primary hyperparathyroidism

Answer 23

functional neoplasms of the parathroid glands secreted inc. PTH and are not downregulated by normal control mechanisms
-cause hypercalcemia

Question 24

what is hypercalcemia of malignancy

Answer 24

-non parathyroid neoplasms secrete PTHrp which mimick actions of PTH but bypass normal pathways that regulate PTH secretion
-leads to hypercalcemia

Question 25

what is vit D toxicity

Answer 25

-due to increased amounts of vit D (ingested or metabolites or endogenous production of these metabolites)
-hypercalcemia and metastatic mineralization can be evidence of severe granulomatous inflamm

Question 26

renal failure causes

Answer 26

retention of phosphates which results in imbalance of Ca and P which may induce parathyroid glands to secrete inc PTH
(secondary hyperparathyroidism)

Question 27

what is bone destruction the result of

Answer 27

primary or metastatic neoplasia that destroys bone

Question 28

common sites of metastatic mineral deposition:

Answer 28

-kidney
-parietal pleura
-pulmonary interstitium
-great vessels/left atrium
-gastric mucosa
-tongue