Blood Supply and Innervation

nutrient vessels

supplies the diaphysis through nutrient foramina

metaphyseal vessels

supplies the diaphyseal surface of epiphyseal cartilage

epiphyseal vessels

supplies the epiphysis

periosteal vessels

supplies superficial osteons of shaft and secondary ossification centers of epiphyses

Lymphatics in periosteum

collects lymph from perforating canals

Vitamin D3/Calcitriol

necessary for calcium absorption

Vitamin C

necessary for collagen synthesis; deficiency causes scurvy

Vitamin A

stimulates osteoblast activity

Vitamin B₁₂

used for protein synthesis in normal bone

growth hormone

enhances protein synthesis and osteoblast activity

thyroxine

increases cell metabolism and osteoblast activity

Androgens and estrogens

sex hormones that increase osteoblast activity

parathyroid hormone

released from parathyroid gland in response to low blood calcium; stimulates osteoclast activity; inhibits excretion by kidneys; promotes absorption in intestines

Calcitonin

secreted from C cells of thyroid gland in response to high blood calcium; inhibits osteoclast activity; promotes excretion by kidney; inhibits absorption by intestine