factors affecting bone development growth and repair

Factors Affecting Bone Development, Growth and Repair

Factors affecting bone development

1. Nutrition (diet and bone)

2. Hormonal regulation of bone growth

3. Excercise and bone

1. Diet and Bone

1. Vitamin D is necessary for proper absorption of calcium in small intestine.

In absence of Vitamin D -- calcium poorly absorbed -- bone matrix lacks calcium -- softening and deforming bone.

In children this condition -- rickets

In adult this condition -- osteomalacia

2. Vitamin A required for normal bone growth and development.

Vitamin A is necessary for osteoblast and osteoclast activity during normal development.

3. Vitamin C is required for collagen synthesis.

Lack of vitamin C -- oesteoblast produces less collagen in intercellular material of bone tissue and resulting bone abnormally slender and fragile.

2. Hormonal regulation of bone growth

Hormones secreted by pituitary gland, thyroid gland, parathyroid glands and ovaries or testis affect bone growth and development.

1. Growth hormone and thyroid hormone, thyroxine and tri-iodothyronine, are specially import during infancy and childhood; deficient or excessive secretion of these results in abnormal development of skeletal.

2. Testosterone and oestrogens influence physical changes that occur at puberty and help maintain bone structure throughout life.

Sex hormone also stimulate ossification of epiphyseal disk, also consequently they stop bone lengthening at relatively early age.

3. Pituitary gland secrete grow hormone, which stimulate division of cartilage cell in epiphyseal disks.

4. Calcitonin and parathyroid hormone

Control blood level of calcium by regulating its uptake into and release from bone.

Calcitonin increases calcium uptake into bone and Parathormone decrease it.

Although length and shape of doesn't normally after ossification is complete. Bone tissue is continually being remodelled and replaced when damaged.

3. Exercise and Bone

Physical stress also stimulate bone growth.

For example, when skeletal muscle contract, they pull at their attachment on bones and resulting stress stimulates bone tissue to thicken and strengthen.

Lack of exercise reverse this changes, leading to lighter, weaker bones.