Calcium and phosphate Flashcards
what is the normal Ca ions concentration in blood plasma
2.4 mmol/L
how does calcium is present in blood plasma
50 % are free Ca ions. unbound to anything, most important form for body function
40% is bound with plasma protein
10% is bound with citrate or phosphate
in which form the Ca can diffuse easily through membrane
free form
in which form Ca is not able to diffuse through capillary membrane
when bind with plasma protein so it stay in circulation
in what form Ca can diffuse through capillary membrane and is easier to use by cell
when bind with citrate or phosphate
what is the tissue that is a large reservoir for calcium and phosphate
bone
which absorption between phosphate and calcium is more efficient
phosphate
what are the 2 form of phosphate in blood plasma after absorption
form of HPO4 (1.05 mmol/L) and H2PO4 (0,26 mmol/L)
what happen with phosphate when the extracellular fluid is more acide
concentration of HPO3 decrease with relative increase of H2PO4
the excretion rate of phosphate is regulated by what
phosphate concentration in plasma and by parathyroid hormone
what is the crital value of phosphate concentration and what happen if it reach it
1mmol/L, all phosphate are reabsorbed and theres no loss into urine
what happen if phosphate concentration is above critical value
excretion in urine is proportional to the increase of phosphate concentration.
the bone are also a reservoir of _ in the _ form
phosphate in the ionic form
up to 30% of bone tissue hase organic matrix composed of
Collagen fibers (majority) that give tensile strength. Ground substance (mionority) including extracellular fluid, chondroitin and
hyaluronic acid (HA).
The rest of bones chemical structure is inorganic salt crystals composed of:
Hydroxyapatite which has the chemical structure consistiong of calcium and phosphate Ca10(PO4)6(OH)2. Many other types of salts of magnesium, sodium, potassium and carbonate ions.
what give the compressional strength to the bone
Hydroxyapatite which has the chemical structure consistiong of calcium and phosphate Ca10(PO4)6(OH)2
the bonne tissue is also surround in a extracellular fluid that contain what
exchangeable Ca and PO4- ions
what are the 2 type of cell that live in bone
osteoclast and osteoblast
which type of cell on the bone secretes collagen monomer and ground substance
osteoblast
what is the ground surface secretes by osteoblast in the pas
proteoglycan
osteoclast is a large _ cell in bone _
phagocytic, marrow
what happen when osteoclast developed
it sends out villus-like projections toward the bone to form a
ruffled border adjacent to the bone.
what are the 2 substances secretes by the villus
- Proteolytic enzymes (released from lysosomes of osteoclast) to digest and dissolve organic matrix.
o 2. Citric acid and lactic acid (released from mitochondria) to dissolve bone salts.
proteolytic enzyme are release from what
lysosome of osteoclast
role of proteolytic enzyme
digest and dissolve organic mattrix
role of citric acid and lactic acid
dissolve bone salt
citric acid and lactic acid are release from
mitochondria
shat is the name of new area of bone deposited
osteon
when does the deposition of new bone stops
when the bone mass begins to encroach the blood vessels
what is the significance of bone remodelling
The new bone replaces the old bone mass that is relatively brittle and weak so that the
normal toughness of bone can be maintained.
because the bone deposition rate is (proportional/ non proportional) to the _ on the bone it can adjust bone _ according to the degree of bone stress
proportional, compressional stress, strength