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 Produce blood cells Red blood cells and some white blood cells Stores the majority of the body’s calcium supply

Bone Composition & Growth Osteoblasts: Cells in bone tissue produce new cells Osteoclasts: Cells that break bone cells down Resorption

Accessory Structures Cartilage: Ligaments Tendons Fibrous connective tissue On end surfaces to prevent friction Ligaments Sheet of fibrous tissue Attaches bone to bone Tendons Attaches muscle to bone

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

Axial skeleton Consists of Skull Spinal column Ribs sternum

Appendicular skeleton Upper extremities Shoulder Arms Forearms Wrists Hands Lower extremities Hips Thighs Legs Ankles feet Pelvis

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

Four groups of bone Flat Irregular 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 Maxilla Lower jaw bone Only moveable bone Upper jaw bone

Thorax Rib cage True ribs False ribs Floating ribs 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-7 Neck Thoracic-12 Chest Lumbar-5 Lower back Largest and strongest

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

Structures of the Long Bone

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 Endosteum Outer covering of bone Layer promote bone growth (ossification) nutrition, and repair Endosteum Lines medullary canal

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

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

Articulation and Movement 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) Elbows, knees, hips, shoulders, ankles

Freely Moveable Joints Freely movable (Synovial) joints of the body Pivot joint Allow rotation on single axis Base of skull Ball and socket allows wide range of movement in many directions Hips and shoulders Hinge joints Allows movement primarily 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. Allows bone to slide Wrist and ankle

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

ROM Lab Flexion: Extension Abduction Adduction Rotation bending a limb at a joint Extension straightening out a limb Abduction Movement away from body midline Adduction Movement toward midline of body Rotation Circular or semi-circular movement around an axis

Disorders of the Skeletal System

Disorders of the Skeletal System Osteomyelitis Severe inflammation of bone and bone marrow, resulting from 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

Fractures Incomplete fracture Complete 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 short bone (vertebral bone)

Fractures Greenstick fracture Incomplete break that occurs almost exclusively in children

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

Fracture treatment Reduction of fractures Manipulation to restore correct anatomical position

Fracture treatment Open reduction Closed 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 with a cast or splint Alleviates muscle spasm around fracture site

Tractions Applies to a pin inserted through distal bone fragment and pulling forces helps return overriding one fragments to normal anatomical position Used until healing takes place or Until internal fixation can be performed

Diagnostic Tests for the Skeletal System

Diagnostic Tests for bones Bone density studies Method of determining how porous bone is Bone marrow biopsy Extraction of a small amount of bone marrow for microscopic examination Bone scan Nuclear medicine procedure Detects amount of radiant energy released from the medication Allows physician to detect fractures osteoporosis, cancer, and growths

Diagnostic Tests for joints Arthrogram Injection of dye into a specific joint followed by series of x-rays Arthroscopy Visual examination of all aspects of a joint using special instrument that contains a light and camera aspiration Removal of excessive fluid from synovial space through a needle

The End