Osteons: tube-like structural units of the compact bone●Concentric lamella: ‘rings’ of bone that form the osteons●Central canal: also called Haversian canal, they are tube-like openings in the osteons that contain blood vessels●Transverse canals: tiny canals that connect between the central canals●Osteocytes: living bone cells●Lacunae: small spaces in the compact bone that house bone cells●Canaliculi: tiny canals that connect the lacunae with each other and with the central canalsJointsWhere two bones meet is called an articulation or a jointsTypes of joints are:●Synarthrotic (immovable) joints
●Amphiarthrotic (slightly moveable) joints●Diarthrodial (freely movable) joints (most common)Cartilage is a cushion that provides protection for joints.Types of cartilage are:●Hyaline: most common; moderate amount of collagen fibers; found in the trachea, nose, epiphyseal plate, articular surfaces of bones●Elastic: contains both collagen and elastin fibers; more flexible than hyaline cartilage; found in ears and larynx●Fibrous: mostly collagen fibers; tough; most often used to absorb shock; found between the vertebrae, pelvic girdle, knee, and shoulder●Tendons attach muscles to bones.●Ligaments connect bones to bones.●Superficial fascia lies immediately under the skin●Deep fascia is a dense, fibrous tissue that surrounds muscle bundles, nerves, and blood vessels●Fascia provides strength to muscle tissuesBursae are small sacs of connective tissue lined with synovial membrane.
●Contains viscous synovial fluid●Located at bony prominences or joints to relieve pressure and decrease friction between moving parts (e.g. patella, olecranon process)Functions of the Musculoskeletal System●Support and protection: ○Sternum and rib cage protects the heart, lungs, kidneys, and liver○Skull protects the brain○Spine protects the spinal cord●Voluntary body motion○Bones provide a base for the muscles, tendons, and ligaments to attach for movement.○Muscles are attached to bones with tendons.○Muscles shorten when they contract and lengthen when they relax. This contraction and relaxation of muscles creates movement of the movable skeletal joints.●Hematopoiesis and fat storage:○Red bone marrow is inside some of the cavities of the bone. Red marrow produces erythrocytes, platelets, and most leukocytes.