Skeletal System

Functions of the skeletal system Framework Support/protect internal organs Body movement Provides leverage for lifting and movement through the attachment of muscles Produced blood cells Red blood cells and some white blood cells Stores the majority of the body’s calcium supply

Accessory Structures Cartilage: On end surfaces to prevent friction Ligaments Attaches bone to bone Tendons Attaches muscle to bone

Axial skeleton Consists of Skull Spinal column Ribs sternum

Appendicular skeleton Upper extremities Shoulder girdle Lower extremities Pelvic girdle

Four groups of bone Long Length is greater than the width Femur Short Blocky bones Similar length/width Wrist (carpal) and ankle (tarsal ) bones

Four groups of bone Flat Composed of two layers with spongy bone between them scapula and skull Irregular Bones of complex shape and structure Facial and vertebrae bones

Bones of the Skull Cranium: encloses the brain (skull) Frontal forehead Parietal Roof and upper sides of cranium Occipital Posterior floor and walls of cranium Temporal Sides and base of cranium

Bones of the Skull Mandible Lower jaw bone Only moveable bone Maxilla Upper jaw bone

Thorax Rib cage Ribs Sternum Thoracic vertebra True ribs Attached to sternum False ribs Attached to ribs above Floating ribs Attached to vertebrae only

Spinal Column Vertebral column 26 vertebrae Types of vertebrae Cervical  neck Thoracic  Chest Lumbar  Lower back  Largest and strongest

Spinal Column Sacrum Triangular shaped Base of spine Coccyx Tail bone End of spine

Structures of the Long Bone

Bone Tissue Compact bone Hard dense part of bone Cancellous Loosely packed or spongy

Structures of bones Long Bone Diaphysis Long shaft of bone Epiphysis Ends of long bone Medullary canal Cavity w/in diaphysis Contains either yellow or red marrow

Structures of bones Tissues of a bone Periosteum Outer covering of bone Layer promote bone growth (ossification) nutrition, and repair Endosteum Lines medullary canal

Structures of bones Bone marrow Red bone marrow Manufactures RBCs & WBCs Ribs, sternum, vertebrae, scapula, ends of long bones Yellow bone marrow Functions as fat storage

Blood cells Erythrocytes Carry O2 and CO2 Leukocytes Fight infection Thrombocytes clotting

Joints Articulation and Movement

Joints Two or more bones join together Three types of joints: Immovable (synarthrosis) Cranium Slightly movable (amphiarthrosis) Pelvis Freely movable (diarthrosis)

Freely Moveable Joints Freely movable (Synovial) joints of the body Pivot joint Allow rotation on single axis Base of skull Ball and socket wide range of movement in many directions Hips and shoulders Hinge joints Allows movement in one direction or plane (bend and straighten) Knees and elbows

Freely Moveable Joints  Saddle joint  Convex and concave surface fit together  thumb  Gliding joint  Two surfaces meet with motion limited by tissues and ligaments  Wrist and ankle

Synovial fluid Lubrication for joints smooth movement of joints Acts as shock absorber Meniscus Fluid-filled disc Reduces friction Bursa Sac lined with synovial membrane Reduces friction

Disorders of the Skeletal System

Disorders of the Skeletal System Osteomyelitis Severe inflammation of bone and bone marrow, resulting form bacterial infection Osteoporosis Bones that have calcium and phosphorous deficiencies Bones are very porous and fracture easily Occurs in women as they age due to estrogen and other hormonal and mineral deficiencies

Disorders of the Skeletal System Arthritis Inflammation of the joint Bursitis Inflammation of the bursa

Disorders of the Skeletal System Gout Accumulation of uric acid crystals in a joint Dislocation Separation of a joint and the malposition of an extremity Sprain Injury to the soft tissues of a joint, characterized by the inability to move, deformity, and pain

Fractures

Greenstick fracture Incomplete break that occurs almost exclusively in children Incomplete fracture Fracture lines does not extend through bone or disrupt the entire thickness of bone Complete fracture Fracture lines goes all the way through bone

Fractures Comminuted fractures Bone broken in several places and splinters of bone can be embedded in surrounding tissue

Fractures Compression fracture Bone collapses due to disruption of bone tissue Usually in vertebrae

Fractures Compound: Causes disruption of skin and soft tissue Fragment of bone punctures skin Often complicated by infection

Fracture treatment-Reduction Manipulation to restore correct anatomical position

Fracture treatment-Reduction Open reduction  surgical incision to expose fracture site  Bone realigned and position with internal fixation (rods, plates, screws) Closed reduction  Local or general anesthesia may be used  Manipulate bone back into normal position

Fracture treatment-Immobilization Immobilization with a cast or splint Alleviates muscle spasm around fracture site

Fracture Treatment-Traction Pin inserted through distal bone fragment and pulling forces helps return overriding fragments to normal anatomical position Used until healing takes place or Until internal fixation can be performed

The End