phys III

Question 1

what is considered hypocalcemia? hyper?

Answer 1

hypo 10.5 mg/dL

Question 2

Sx hypocalcemia

Answer 2

twitching, muscle cramps, tingling, numbness

Question 3

Sx hypercalcemia

Answer 3

constipation, polydipsia, polyuria, lethargy, coma, death

Question 4

majority of phosphate in plasma is in what form

Answer 4

ionized

Question 5

majority of Ca in plasma is in what form

Answer 5

50% ionized 45% protein bound

Question 6

what binds Ca

Answer 6

albumin

Question 7

What does albumin bind in acidemia

Answer 7

more H than Ca so more ionized Ca

Question 8

what does albumin bind in alkalemia

Answer 8

more Ca than H so less ionized Ca

Question 9

what hormones regulate Ca

Answer 9

PTH, 1,25-dihydroxyvitamin D

calcitonin

Question 10

what organs regulate Ca

Answer 10

skeleton, kidney, intestines

Question 11

what is the Ca sensor R

Answer 11

7 membrane GPCR
senses extracell Ca- ionized Ca
R found on parathyroid cells, parafollicular c-cells and renal tubular cells

Question 12

what sitmualtes bone resorption? what inhibits it

Answer 12

stimulated by PTH and 1,25 dihydrovit D

inhibited by calcitonin

Question 13

functions PTH

Answer 13

• Ca and phospate resorption from bone
• promotes Ca resorption from kidney
• promotes phosphate excretion from kidney
• signals 1alpha hydroxylation of 25-hydroxycholecalciferol in kidney

Question 14

functions of 1,25(OH)2 vit D

Answer 14

bone remodeling promotes mineralization
Ca absorption from gut
renal resorption of Ca and phosphate
negatively feedbacks on its own conversion

Question 15

What suppresses PTH secretion

Answer 15

high levels extracell Ca

Question 16

how does PTH increase bone resoprtion

Answer 16

acts on R on osteoblasts which stimulate osteoclasts

Question 17

severe deficiencies Vit D can cause what

Answer 17

osteomalacia and rickets

Question 18

what is osteopetrosis and what can cause it

Answer 18

increase in bone density, loss of RANKL

Question 19

what is Osteoprotegerin OPG

Answer 19

soluble R for RANKL and shuts down resorption by osteoclases

Question 20

if you lose OPG what results, and why

Answer 20

decrease in bone density, osteoporosis because unregulated RANKL is activation osteoclasts

Question 21

what is needed to activate the conversion of 25 OH to 1,25 OH in kidney

Answer 21

decrease Ca [ ]
increase PTH
decrease PO4 [ ]

Question 22

what levels classify severe, moderate, mild and normal Vit D deficiency

Answer 22

normal is >30ng/ml
mild 20-30
moderate 10-20
severe 0-10

Question 23

if PTH is super super high and blood Ca is low what will you suspect?

Answer 23

kidney failure

Question 24

if PTH is super high and Ca is normal-high what do you suspect

Answer 24

primary hyperparathyroidism

Question 25

if PTH is elevated and Ca low what do you suspect

Answer 25

Vit D deficiency

Question 26

what id PTH is super low, almost 0 and Ca super high

Answer 26

High Ca of malignancy

Question 27

What are the hyperCa disorders

Answer 27

``` primary hyperPTH hyperCa of malignancy granulomatous disease Vit D intoxication Vit A intoxication hyperthyroidism thiazide diuretics milk-alkali syndrome immobilization adrenal insufficiency acute renal failure familial hypocalciuric hyperCa ```

Question 28

what can cause familial hypocalciuric hypercalcemia

Answer 28

heterozygous inactivation mutation in CaSR | increase PTH and serum Ca

Question 29

what is key test in Dx hypercalcemia cause

Answer 29

serum PTH

Question 30

causes of hypoCa

Answer 30

``` Vit D def hypoPTH pseudohypoPTH hypoMg Renal failure liver failures acute pancreatitis hypoproteinemia ```

Question 31

what are key tests in Dx hypocalcemia

Answer 31

25-OH vit D measurement and PTH

Question 32

if PTH levels are low and patient is hypcalcemic what is Dx

Answer 32

hypoPTH because all other causes hypoCa have high PTH or normal

Question 33

how do renal and liver disease contribute to hypocalcemia

Answer 33

interfere with Vit D synthesis

Question 34

how does acute pancreatitis lead to hypo Ca

Answer 34

precipitation of Ca from release of lipid products

Question 35

what is the key abnormal blood level in pagets disease

Answer 35

increased alkaline phosphatase | have bone pain as cc