Calcium and Phosphate

Question 1

Ca

Answer 1

Most abundant cation
Tight regulated range in plasma (2.2-2.6 mM)
Membrane stability and cell function
Neuronal transmission
bone structure/formation
Blood coagulation
Muscle function
Hormone secretion

Question 2

Phosphate

Answer 2

Cellular energy metabolism (ATP_
Intracellular signaling pathways
Nucleic acid backbone
Bone structure
Enzyme activation/deactivation

Question 3

Hypocalcelmia

Answer 3

Muscle failure
Tetany
Convulsions
Death

Question 4

Hypercalcemia

Answer 4

Renal Dysfunction
Calcification of soft tissues
Muscle weakness
Coma

Question 5

Hyperphosphatemia

Answer 5

result of severe tissue injury “crush”

Question 6

Regulators of Ca

Answer 6

PTH
Vit D (calcitriol, skin/diet)

Question 7

Calciferol

Answer 7

General term for vitamin D and other natural structural analogs

Question 8

Cholecaciferol

Answer 8

Specifically refers to vitamin D3 (from animal tissues)

In skin converted by light, D3 released into blood

Question 9

Calcidiol

Answer 9

Calcifidiol
25-hydroxy-vitamin D
(25-D)
Immediate precursor
In very high abundance, more so than the active form.
Though does not bind the receptor as well.

Question 10

Calcitrol

Answer 10

Calcifitriol
1,25-dihydroxy-vitamin D
(1,25-D) = 1,25-dihydroxy-cholecalciferol (this is the active form)

Question 11

Ergocaliferol

Answer 11

Vitamin D2

Dietary from vegetables

Question 12

Pleiotropic effects of Vit D

Answer 12

MS
Asthma
Cardiovascular disease
DM2
Colorectal/breast cancer

Question 13

Osteoporosis

Answer 13

Reduced bone density (trabecular)
Causes: genetic, menopause (low estrogen), cortisol (glucocorticoid therapy/chronic stress), low dietary Ca
Treatment: Estrogens, calcitonin (parafollicular cells of thyroid), bisphosphonates (inhibit bone resorption), Vit D

Question 14

Hyperparathyroidism

Answer 14

Primary: hyperplasi, carcinoma of parathyroid gland
Hypercalcemia, kidney stones
Secondary: due to chronic renal failure (reduced vit D leads to excess PTH synthesis)

Question 15

Hypoparathyroidism

Answer 15

Hypocalcemic tetany (because threshold went down)

Chvostek sign: twitching of acial muscles in response to tapping of facial nerve

Question 16

Rickets (children)

Osteomalacia (adults)

Answer 16

Unmineralized bone due to Vitamin D deficiency
Bowing of long bones (children)
Decreased bone strength

Question 17

Pseudohypoaparthyroidism

Answer 17

Congenital defect in G protein that associates with PTHR1
Generalized resistance to PTH, TSH, LH, and FSH
Clinical signs; low Ca, high phosphate, elevated PTH, short stature

Question 18

Urinary hydroxyproline

Answer 18

If you see it in the urine it is indictive of enhanced bone resorption