Calcium Regulation

Question 1

Hypocalcemia signs

Answer 1

hyperreflexia, twitching, muscle cramps, tingling/numbness

Question 2

Chvostek sign

Answer 2

facial m. twitches when facial nerve is tapped

Question 3

Trousseau sign

Answer 3

carpopedal spasm upon inflation of a blood pressure cuff

Question 4

Hypercalcemia signs

Answer 4

decreased QT interval, conspitation, lack of appetite, polyuria, polydipsia, muscle weakness, hyporeflexia, lethargy, coma

Question 5

Vit D causes

Answer 5

Ca intake in the intestines by synthesizing calbinin transporter

Ca resorption from the bone

Ca reABsorption from the kidney

Question 6

Vit D vs PTH in the kidneys

Answer 6

Vit D stimulates Ca AND phosphate reabsorption

PTH stimulates Ca reabsorption but inhibits phosphate reabsorption

Question 7

Where are the major actions of 1,25-hydroxycholecalciferol?

Answer 7

in the intestines where it stimulates calcium absorption via upregulation of calbindin D28K that can bind four Ca ions

Question 8

Vit D vs PTH on bone formation

Answer 8

Vit D upregulates RANKL expression

PTH upregulates RANKL and downregulates OPG (osteoprotegrin, inhibitor of RANK-RANKL interactions)

Question 9

cAMP generated by PTH stimulation

Answer 9

excreted in urine, indicates high PTH stimulation

Question 10

estradiol-17beta

Answer 10

stimulates calcium absorption from intestine

potent regulator of osteoblast/clast function by promoting osteblast survival and osteoclast destruction

Question 11

adrenal glucocorticoids

Answer 11

promotes bone resorption and renal expulsion of calcium (calcium wasting)

high levels of cortisol leads to osteoporosis

Question 12

Primary Hyperparathyroidism

Answer 12

increase in calcium reabsorption, increase in Vit D activation, decease in phosphate reabsorption

Question 13

Secondayr Hyperparathyroidism

Answer 13

PTH is high because some issue is causing calcium levels to be low in the body

renal failure, vit. d deficiency etc

Question 14

renal failure causes what parameters on PTH, Ca, P, and VD?

Answer 14

decrease in Ca, increased P, decreased VD, increase in PTH

Question 15

Vit D deficiency causes what parameters on PTH, Ca, P, and VD?

Answer 15

increased PTH, decreased Ca, decreased P, decreased VD

Question 16

Primary hyperparathoridism vs secondary

Answer 16

primary is when there is something wrong with the parathyroids like an adeoma, seconday include renal failure an vit D deficiencies

Question 17

Hypoparathyroidism

causes

Answer 17

thyroid surgery
parathyroid surgery
autoimmune or congenital dysfunctions

Question 18

Hypoparathyroidism

associated with

Answer 18

most ass. with decreased calcium

muscle spasm, cramping, numbness, etc

seizures, poor teeth, etc

treatment: oral Ca supplement and active form of vitamin D

Question 19

main parameters of hypoparathyroidism

Answer 19

decrease in Ca, vit D, PTH but INCREASE IN P

Question 20

Pathophysiology of PTH

Answer 20

albright hereditary osteodystrophy

pseudohypoparathyroidism type 1a

Gs in bone and kidney is defective.

hypocalcemia and hyperphosphatemia

Question 21

in which disorder is there a decrease in adenylyl cyclase activity

Answer 21

albright hereditary osteodystrophy

pseudohypoparathyroidism type 1a

this is where the Gs protein doesnt activate for activate adenylyl cyclase activity

Question 22

parameters of pseudohypoparathyroidism

Answer 22

increased PTH
increased P
decreased calcium
decreased Vit D

Question 23

phenotype of psuedohypoparathyroidism

Answer 23

shortened stature, short neck, obesity, subcutaneous calcification, shortened metatarsals, metacarpals