ANT 2100 1st Edition Lecture 11I. Bone Development (ossification) i. When studying bone histology it is very important to understand the between compact bone and spongy (cancellous) bone. a. Compact bone is the external layer of bone b. Composed of osteon 1. Osteons are a tube of bone matrix formed by rings called concentric lamellae 2. Cell bodies of osteocytes are located in the lacunae between the concentric lamellae 3. Osteocytes pass oxygen and nutrients to each other by way of their cell processes by the Haversian Canal 4. The central canals are connected to each other by the perforating canals (Volkman’s canal) ii. Spongy (cancellous) bone is surrounded by the compact bone (inside) a. No osteons presentb. Composed of plates of bones called trabeculae c. Constantly replaces itself d. Keeps bone strong e. Anatomy of bone reflects the stresses it encounters iii. Ossification- process of forming the bony skeleton a. There are two types of ossification intramembranous ossification and endochondral ossification b. intramembranous ossification- bone originates from connectivetissue membrane (flat bones of skull, and the clavicles)c. endochondral ossification- bone originates from hyaline cartilage (most bones from the skeleton)II. Articulations and Movements i. An articulation is where two are more bones join (joints) a. Give the skeleton mobility and hold together ii. Classification of joints all joints have functional and structural classification a. Functional classification is based on the amount of movement occurring at the joint b. Synarthroses- non-movable c. Amphiarthroses- slightly moveable These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.d. Diarthroses- freely movable e. Structural classifications are based on what binds bonestogether f. Fibrous joints- bones that are united by collagen fibers g. Cartilaginous joints- bones united by a plate of cartilageh. Synovial joints- bones separated by a fluid filled joint cavity, very movable, most joints of the body iii. Structure of synovial joints a. Articular cartilage- hyaline cartilage found on the end of long bones (provides smooth surface, reduces frictions, and absorbs shock) b. Joint (synovial) cavity- space the surrounds joint, synovial fluid- reduces friction and nourishes cartilage cells. Joint (articular) capsule- encloses joint, hold synovial fluid, fibrous capsule-outer layer of joint capsule, composed of connective tissue, synovial membrane- lines the inside of the fibrous capsule, produces synovial fluid iv. Reinforcing ligamentsa. Strengthen and stabilize joints b. Bursae- sac filled with synovial fluid to reduce friction c. Tendon sheaths- elongated bursae which wrap around tendons reduces