Minerals

Question 1

(Calcium and Phosphorus)

(determined by a balance of intake and loss)

(intestine)

1. based on need

mediated by what?

influenced by what?

(bone)

2. uptake/release of sodium (Ca?) with bone resorption/formation

(kidney)

3. normally reabsorbs most filtered Ca and P

what influence renal regulation?

Answer 1

1. vit D

corticosteroids

3. PTH, calcitonin, vit D

Question 2

(PTH)

1. responds to low or high Ca?

by doing what?

also decreases renal absorption of what?

2. What has similar effects?

Answer 2

1. low

^osteolysis, bone resporption, skeletal remodeling, ^renal reabsorption, ^Vit D

Phosphorus

2. PTHrP

Question 3

(calcitonin)

1. released in response to what?

does what?

result?

Answer 3

1. hypercalcemia

inhibits bone resorption, promotes renal phosphrus loss

dec Ca and Phosphorus

Question 4

(Vitamin D)

1. activation stimulated by what?
2. hydroxylated in liver, activated in kidney
3. What is its major action?

what block this action?

4. net result?

Answer 4

1. PTH, low Ca or P
2. ^intestinal absorptino of Ca and Phoshoprus

glucocorticoids (dec Vit D receptors)

4. ^ Ca and P

Question 5

Effect of PTH, Calcitonin, and Vit D?

Answer 5

Question 6

(Forms of Phosphorus)

1. major intracellular anion (ATP, etc)
2. most in cells and organic
3. What do we measure?

Answer 6

3. extracellular (inorganic)

DOES NOT REFLECT TOTAL BODY STORES!!!

Question 7

(Forms of Calcium)

1. Ionized = ?

PTH and calcitonin react to ionized or non-ionized form?

2. How much is protein bound?

affected by what?

3. How much is complexed to cirtrate/phosphorus
4. We routinely measure what?

Answer 7

1. bio active form (50%)

ionized

(ionized Ca increased by acidosis (and vv))

2. 40-45%

acid/base

3. 5-10% in health
4. total calcium

Question 8

(General guidelines)

1. interpret Ca/P together

which ∆ is more consistnet?

2. what do young animals show?

Answer 8

1. Ca
2. ^ Ca and P (bone remodeling)

Question 9

(Low Ca/normal P)

1-3. What are the causes?

Answer 9

1. hypoalbuminemia (most common cause in dogs)

dec protein bound Ca

2. acute pancreatitis

(P may increase if concurrent dec GFR)

3. colic in horses

low albumin, dec GI absorption

dec abs with potential for altered PTH activity

Question 10

(Low Ca, High P)

1. what cause?

(ethylene glycol also causes but we are ignoring that for now )

Answer 10

1. primary hypoparatyhroidism

severely decreasd total and ionized

^P due to failure of PTH to promote renal P loss

Question 11

(Low Ca/Low P)

what 2 causes?

Answer 11

1. loss into milk

(most common cause of hypocalcemia in cows (delayed recovery response to milk/fetal bone formation)

2. decreased intestial absorption

(malabsorption, anorexia (ruminants), steatorrhea/pancreatitis (dec vit D abs)

generally mild and asymptomatic

Question 12

(High Ca/normal to low P)

1-2 what two causes?

Answer 12

1. primary hyperparathyroidism

dec P (unless Ca causes renal failure)

2. Hypercalcemia of malignancy (at first)

more in notes on this…

Question 13

(high Ca, High P)

1. when Ca X P > 60-70 patient at risk for what?

2-3 what two things cause?

Answer 13

1. soft tissue mineralization (esp kidney!)
2. ^vitamin D (rodenticitde/plant toxicity)

(^Ca can cause 2° renal failure, can lead to mineralization cause Ca X P is high)

3. hypoadrenocorticism

(^ionized Ca can be high)

(^P (mild) from dec GFR)

Question 14

(Normal Ca, ^P)

1-2. What are two causes?

Answer 14

1. decreased GFR (pre/renal/post) - most common cause

Ca normal in pre/post, can be anything in normal

2. musc or tissue damage (must be massive)

(increased P, K, AST, CK)

Question 15

(normal Ca, dec P)

???

Question 16

(Magnesium)

(not well understood)

1. low?
2. high?

Answer 16

1. dietary in LA, or in critical care patients
2. dec GFR