VAN 111: Veterinary Gross Anatomy - I (1+2)

GROWTH OF BONES

• Flat bones of the skull increase in size by continued marginal ossification from connective tissue at the site of later sutures.
• Both cartilage and membranous bones grow in thickness through further deposition of matrix at their outer surfaces.
• At the ends of a long bone a layer of cartilage does not ossify and remains as articular cartilage throughout life.
• In growth phase, a portion of the cartilagenous model remains as epiphyseal cartilage cartilage between the epiphysis and diaphysis.
• The epiphyseal cartilage helps in longitudinal growth of the bone and is replaced totally by bone when the growth is complete. Therefore the length of the bone increases with the growth of the epiphyseal cartilage. But with the advancement of the age, the growth of this metaphyseal cartilage slows down and the calcification becomes more rapid. So the whole epiphyseal cartilages become ossified and growth in length ceases.
• The width increases by the deposition of subperiosteal membrane bone.

Factors influencing the development and growth of bones

• They are include calcium phosphorous, vitamin D, vitamin C, alkaline phosphatase, parathyroid hormone, growth hormone of pituitary, thyroid hormone and vitamin A.