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The Skeletal System. Outline - Introduction. Tissues of the Skeletal System Bone Growth and Repair Bone Development Bone Repair Bones of the Skeleton Bone Classification Axial and Appendicular Skeleton Articulation Movements Permitted by Joints . Tissues of the Skeletal System.
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Outline - Introduction • Tissues of the Skeletal System • Bone Growth and Repair • Bone Development • Bone Repair • Bones of the Skeleton • Bone Classification • Axial and Appendicular Skeleton • Articulation • Movements Permitted by Joints
Tissues of the Skeletal System I) Introduction II) Connective Tissues A) Bone B) Cartilage C) Fibrous connective tissue
A) Bone (Ca2PO4 + mineral salts) • 1) Compact bone - organized, tubular osteons. • Osteocytes lie in lacunae, tiny chambers arranged in concentric circles around a central canal. Canaliculus • 2) Spongy bone – trabeculae, unorganized. • Spaces are often filled with red bone marrow. Osteocytes irregular
B) Cartilage • Cartilage is flexible w/ gel-like matrix contains collagenous and elastic fibers. - Chondrocytes - Blood/Nerve supply • Three types differ according to type and arrangement of fibers. • Hyaline - Firm and flexible. Ends of bones • Fibrocartilage - Strong. disks • Elastic - Flexible. Ear, epiglottis
C) Fibrous Connective Tissue • Made of rows of fibroblasts separated by bundles of collagenous fibers. • Makes up ligaments and tendons
Bone Structure • Epiphysis, diaphysis, medullary cavity • Yellow bone marrow • C) Periosteum
Bone Growth and Repair • Several different types of cells are involved in bone growth and repair. • Osteoprogenitor cells – unspecialized. • Osteoblasts – bone-forming/matrix secretion. • Osteocytes - mature • Osteoclasts – bone reabsorption • Ossification - bone formation.
Remodeling of Bones • Osteoclasts break down bone, remove worn cells, and assist in depositing calcium in the blood. • Osteoblasts take calcium from blood and form new bone.
Bone Repair • Fracture repair takes place over a span of several months in a series of four steps. • Hematoma (6-8 hrs) • Fibrocartilaginous callus (3 wks) • Bony callus (osteoblasts, spongy, 3-4 months) • Remodeling (osteoblasts = compact) (osteoclasts = spongy) • Naming of a fracture indicates what kind of break occurred.
Bones of the Skeleton • Skeletal Functions. • Support body. • Protect soft body parts. • Produce blood cells. • Store minerals and fat. • Permit flexible body movement.
Bone Classification • Bones are classified according to their shape, and whether they occur in the axial skeleton or the appendicular skeleton. • Axial - Midline. • Appendicular - Limbs and their girdles. • 206 total bones in body
The Axial Skeleton • The axial skeleton lies in the midline of the body and consists of: • Skull (8 bones) • Hyoid bone. • Vertebral column (33 bones) • Rib cage (12 pairs)
The Appendicular Skeleton • The appendicular skeleton consists of bones within the pectoral and pelvic girdles and their attached limbs.
Articulations • Bones are joined at joints. • Cartilaginous joints are connected by hyaline cartilage. • Synovial joints separate the bones by a cavity. • Hinge. • Ball-and-socket.
Movements Permitted by Synovial Joints • Angular Movements. • Flexion- Decreases joint angle. • Extension - Increases joint angle. • Adduction - Movement towards midline. • Abduction - Movement away from midline.
Movements Permitted by Synovial Joints • Circular Movements. • Rotation - Movement around axis. • Supination - Rotation with palm upward. • Circumduction - Movement in wide circle. • Special Movements. • Inversion(sole inward) and eversion (sole outward). • Elevation (lifting up) and depression (moving down).