THE MATRIX
Bone tissue differs from all other connective tissues. Its matrix has
not only organic components (same as all the other connective tissues)
but also abundant inorganic components
that set it apart structurally and functionally from all other tissues.
Roughly, the matrix is about 20% water, 20% protein and 60% mineral salts.
Inorganic Components:
- They are mineral salts,
mainly Hydroxyapatite
(a cristallized form of tricalcium phosphate),
some calcium carbonate, and small amount of magnesium hydroxide,
fluoride and sulfate.
- They give the bone its characteristic that makes it unique among
all the other tissues: an exceptional HARDNESS
which allows it to resist compression.
- Mineral salts are abundants: they make 65% of the bone mass and nearly 2/3 of the matrix.
Organic Components:
- The organic component of the bone matrix is called osteoid.
- It contains proteoglycans, glycoproteins and collagen fibers.
- Without the organic components of the matrix, the bone would be very brittle and
it would break if twisted or stretched.
These organic molecules, especially the collagen fibers act
like reinforcing metal rods in concrete (the concrete here being the mineral salts).
They provide bone with great flexibility and tensile strength
(resistance to being stretch or torn apart).
