Hydroxyapatites (mineral salts) make up about 65% of bone mass and are responsible for hardness and resistance to compression. This describes which component of bone matrix?

Hydroxyapatites (mineral salts) make up about 65% of bone mass and are responsible for hardness and resistance to compression. This describes which component of bone matrix?

• A. Inorganic components (of bone matrix)
• B. Organic components (of bone matrix)
• C. Osteocytes
• D. Periosteum

Answer: (A)

Hardness and resistance to compression come from the mineral salts in bone, specifically hydroxyapatite. This makes up the inorganic portion of the bone matrix, the part that provides rigidity by filling spaces within the organic scaffold. The organic portion, mainly collagen, offers flexibility and tensile strength, but the mineral component is what makes bone hard enough to support body weight. Osteocytes are the bone cells embedded in the matrix, and the periosteum is the outer covering; neither is the mineral part responsible for hardness. So this description points to the inorganic components of the bone matrix.

Hardness and resistance to compression come from the mineral salts in bone, specifically hydroxyapatite. This makes up the inorganic portion of the bone matrix, the part that provides rigidity by filling spaces within the organic scaffold. The organic portion, mainly collagen, offers flexibility and tensile strength, but the mineral component is what makes bone hard enough to support body weight. Osteocytes are the bone cells embedded in the matrix, and the periosteum is the outer covering; neither is the mineral part responsible for hardness. So this description points to the inorganic components of the bone matrix.