Bones

Role of bone

• Ossified connective tissue - 25% water, 25% protein fibres and 50% minerals
  • Calcium, Phosphorous, plus some calcium carbonate and magnesium to form hydroxyapatite
• Supporting and protecting soft tissues with minimal weight
• Attachment sites for muscles, enabling movement
• Reservoir for calcium and phosphate - enables mineral homeostasis
• Red bone marrow in flat bones and the end of long bones.
  • Site of haemopoiesis (production of red and white blood cells and platelets
• Yellow bone marrow stores triglycerides and acts as an energy store

Structure

Bones have distinctive regions:

• Diaphysis: shaft of the bone
• Epiphysis: cartilage growth plate at the end of the bone (epiphyseal line)
• Metaphysis: between diaphysis and epiphysis where growth occurs
• Periosteum: tough membrane covering bone but not cartilage, helps increase thickness
• Medullary cavity: contains yellow…