Bone Structure

Long Bone Anatomy Diaphysis – Shaft -Composed of compact bone Epiphysis – Ends – Spongy bone surrounded by compact bone Periosteum – Fibrous protective membrane that covers the diaphysis Perforating fibers – Connective tissue fibers that attach periosteum to bone Articular cartilage – Glassy, smooth hyaline cartilage layer that covers the epiphysis – Helps reduce friction

Long Bone Anatomy (Cont.) Medullary canal – Canal in the center of the bone Adults – Fat storage (yellow marrow) Infants – Filled with red marrow (makes blood cells) Red Marrow – Responsible for hematopoiesis Adults – Found in cavities of spongy bone Infants – Found in medullary canal

Long Bone Anatomy (Cont.) Epiphyseal line – Remnant of the epiphyseal plate Epiphyseal plate – Flat plate of hyaline cartilage – Site of the lengthwise growth of bone

Anatomy of an Osteon Osteocytes – Mature bone cells found in the lacunae Lacunae - Tiny cavities in bone matrix that contain osteocytes Lamellae – Circles in the bone tissue that contain the lacunae – Look like tree rings Haversian canal – Canal in the middle of the osteon – Allows neurovascular bundles to pass through

Anatomy of an Osteon (Cont.) Canaliculi – Tiny canals radiating from Haversian canal to all lacunae Volkmann’s (Perforating) Canal – Canals that run at a right angle to the Haversian canal