Minerals Flashcards
What is the major mineral in the body?
Calcium
How is calcium distributed in the bidy?
99% is found in the bones while 1% is free in plasma and cells.
What are the extracellular functions of calcium?
Bone and tooth development and function
Hemostasis/coagulation cofactor
What are the intracellular functions of calcium?
Nervous system communication
Muscle contraction
Cellular function like cell division and glycoprotein metabolism
Hormone secretion
What are the three physiochemical states of circulating calcium and how are they distributed?
Free (50%)
Bound (40%)
Complexed (10%)
Calcium is sometimes complexed with
Small anions like citrate, lactate, phosphate, bicarbonate
How is free calcium regulated?
By interaction of PTH and vitamin D
How does PTH increase calcium?
Enhancing calcium resorption from bone, activation of vitamin D, reabsorption by renal tubules
What allows cakcium to cross intestinal walls?
Vitamin D
What enzyme turns inactive vitamin D into active hormone calcitriol?
Hydroxylase
What are the symptoms of hypocalcemia?
Nerve excitability: tetany, spasms, cramps
Muscle weakness (heart arrhythmia)
Coagulation problems
Osteoporosis/osteomalacia
What causes hypocalcemia?
Hypoparathyroidism
Decreased Vitamin D synthesis or uptake
Decreased calcium intake
What are the symptoms of hypercalcemia?
Polydipsia
Polyuria
Hypertension
Kidney stones
What causes hypercalcemia?
Cancer of bone
Hyperparathyroidsm
Excess vitamin C
How does pH affect free calcium levels?
Lower pH causes higher free calcium
Why do smalles for measuring calcium need to be keepmcold or analyzed promptly?
Because cell metabolism decreases pH which will result into false readings.
What methods are used to analyze calcium?
Ion-selective methods
How is phosphate distributed?
Most phosphate is found complexed with calcium (inorganic)
Rest is found in cells (organic)
Hiw are levels of calcium and phosphate in bone cancer?
Both levels rise
What are the functions of the inorganic component of phosphate?
Bone support when complexed with calcium
What are the functions of organic component of phosphate?
Phosphate is a component of ATP & GTP, important for cellular metabolism
Important component of the cell membrane and lipoprotein as phospholipid
Hiw is phosphate regulated?
Bone resorption
PTH
Vitamin D
What are the symptoms of hypophosphatemia?
Muscle weakness and depletion Softening of bones Respiratory difficulties (lack of atp) Decreased cardiac output (lack of atp) Rhabdomyolysis
What is rhabdomyolysis?
Destruction if muscle duebto really low phosphate causing ATP depletion
What causes hypophophatemai?
Intracellular shift (insulin overuse, poorly managed diabetes)
Primary hyperparathyroidism
Deceased vitamin D
What symptoms are seen in hyperphosphatemia?
Muscle cramps Numbness Tingling Tetany Siezures
What causes hyperphosphatemia?
Renal failure, reduced GFR
Increased phosphate intake/absorption (laxatives, vitamin d toxicity)
Mass cell lysis (chemo)
How is magnesium distributed in the body?
55% in the bone, muscle, cells, and free in plasma.
What are the fun tions of magnesium?
Bone support
Enzyme actuvator especially for CK
