Disorders of Ca metabolism Flashcards
PTH effects
directly on kidney/bone; indirect on GI via vit D
which form of vitamn D comes from animal vs plants
- D3 from animals/we make in skin
- D2 from plant source (also has molecules inhibiting absorption)
major vitamin D store
25 hydroxyvitamin D– fat soluble— big reservoir
is hydroxylation regulated
No; based on mass effect
what regulates creation of 1, 25 (OH)2 vit D
PTH
parathyroid disorders vs vitamin D disorders
- vitamin D disorders: Ca and phosphate go in same direction since it increases Ca and phosphate absorption
- parathyroid disorders: moves Ca and P in opposite directions
vit D actions
increase Ca and P absorption
- at higher leves, increases bone resorption
Calcitonin
smaller hormone reducing Ca by reducing osteoclastic activity mainly
how do we regulate serum Ca/detect low Ca
Parafollicular C cells/parathyrod cells/renal tubular cells all have Ca sensor receptor– signals to inside of cell what level of Ca is
Hypercalcemia disorders
- primary hyperparathyroidism
- hypercalcemia of malignancy
- granulomatous disorders (express 1alpha hydroxylase enzyme–so high 1, 25 vit D)
- vit D/A intoxication
- hyperthyroid
- thiazide diuretics
- Milk-Alkali syndrome
- immobilization
- adrenal insufficiency
- acute renal failure
- family hypocalciuric hypercalcemia
most common hypercalcium disorder
primary hyperparathyroidism,
hypercalcemia of malignancy
what do you order after see high Ca to help with diagnosis
PTH–
- PTH elevated in hyperparathyroidism and low in all other except familial hypocalciuric hypercalcemia
- low PTH– more likely malignancy
brown tumors
hyperparathyroidism causes
85% due to adenoma and the other 3 are atrophied
- 15% due to hyperplasia–usually familial and 4 glands affected
-
clinical features of primary hyperparathyroidism
- > 50% asymptomatic
- sk disease
- kidney disease
- GI disease
- psych disease
(Bones, Stones, Groans, Moans) - arthritis, muscle weakness, Band Keratopathy, HTN , anemia
most common sxs of primary hyperparathyroidism
NO SXS!!
Osteoclastoma
benign “brown tumor”
- severe hyperparathyroidism–once tumor removed, osteoclast dies and spot filled in
Band keratopathy
band of Ca deposition of cornea medially/laterally– circumferential