The Skeletal System Bones are the primary organs of the skeletal system. Bones are living organs. Allow us to grow. Articulation = joint

Functions of the Skeletal System Support The body’s framework Protection Example ribs protect heart; skull protects brain Movement Muscles anchor to bone When they contract they pull bone allowing movement Storage calcium Hematpoiesis Blood cell formation

Types of Bones Names suggest their shape Long (humerus) Short (carpals-wrist bones) Flat (frontal- skull bone) Irregular (vertebrae) Most important are the long bones

Structure of Long Bones Diaphysis- shaft- a hollow tube made of hard compact bone Medullary cavity- hollow area inside diaphysis Contains yellow bone marrow- an inactive fatty form of marrow Epiphyses- ends of the bone- red marrow fills in the spaces between spongy bone Articular Cartilage- thin layer of cartilage covering the epiphysis Functions like a small rubber cushion

Structure, continued Periosteum- strong fibrous membrane covering the long bone, except where covered by articular cartilage Endosteum- thin membrane that lines the medullary cavity

Bone tissue Compact Spongy Outer layer and along shafts of long bone Tightly packed Osteons* Spongy Instead of Osteons contains bars and plates called trabeculae Holes between give the porous apperance

Osteon Structural (inside the bone) unit of compact bone tissue made up of concentric layers of hard bone matrix and bone cells Also called Haversian systems

Each osteon is arranged in multiple layers resembling the ring of an onion called Lamella Thin layer Circular rings

Bone Growth and Repair Ossification or osteogenesis Begins at 8 weeks post conception Osteoblasts- cells that form bones Osteoclasts- breaks down old bone Epiphyseal plate- “growth plate” Thin band of cartilage between ossified sites

Cartilage Unlike bone, cartilage fibers are embedded in a firm gel instead of calcified cement substance, which allows it to be more flexible Chondrocytes- cartilage cells, located in the lacunae Cartilage has no blood vessels which make it slow to heal if damaged.

Cartilage, cont Articular cartilage- located on ends of bones Bursa- contains synovial fluid Arthritis- when this cartilage and synovial fluid wear out or become inflamed

Differences between male and female skeletons Size- most males are larger Hipbones- Males bones are larger, but females tend to be wider to allow for childbirth Males form a funnel shape Females more of a basin shape Where the 2 pubic bones meet on a female are also wider

Divisions of Skeleton Axial- bones of the skull, spine, chest, and the hyoid Appendicular- upper and lower extremities or appendages

Axial Skeleton Skull -8 bones form the cranium -14 bones form the face -6 bones form the inner ear

Skull, cont. Sinuses- spaces or cavities inside some cranial bones Four pairs open to the nose = paranasal sinuses Mastoiditis – inflammation of the air spaces within the mastoid portion of temporal bone

Skull, cont. Sutures Fontanels Immovable joints in bones “soft spots” 6 at birth allow compression of the skull during birth Fuse to form sutures by age 2 http://www.mayoclinic.com/health/babys-soft-spots/MM00082

Spine (Vertebral Column) spinous process Transverse process Vertebral foramen Palpate C7

Spine Curvatures Pg. 195 Lordosis Kyphosis Scoliosis

Vertebral Bones Cervical 7 Thoracic 12 Lumbar 5 Sacrum 1 Coccyx 1

Thorax 12 pairs of ribs Sternum Thoracic vertebra First 7 “true ribs” attach to sternum 8-10 “false ribs” attach to cartilage of the 7th pair 11-12 not attached to costal cartilage “floating ribs” Sternum Thoracic vertebra

http://www.youtube.com/watch?v=Nc5IRj3OJhE

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Bone Fractures Fracture = Break One isn’t worse than the other, they are the same thing! Callus- bony framework that “fixes” a fracture

Bone Fractures Open or compound fracture Bone comes through the skin Increased possibility of infection or osteomyelitis

Bone Fractures Closed or simple fractures Complete fractures Skin remains intact Complete fractures Bone fragments are completely separated Incomplete fractures Bone fragments are still partially joined Greenstick fractures- bone is bent and breaks only on the outer bend. Common in children, heals rapidly

Bone fractures Comminuted fractures Impacted fractures Breaks into many pieces Impacted fractures Bone fragments are driven into each other Spiral fractures Occurs when torque is occurring to the bone

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Epiphyseal Fracture Avulsion Fracture Overstress in young athletes Epiphyseal plate separates from the diaphysis or the epiphysis Without treatment proper growth may be inhibited Avulsion Fracture Muscle contraction pulls away a piece of the underlying bone

Joint Disorders Classified as Noninflammatory joint disease

Noninflammatory Joint Disease Osteoarthritis also known as degenerative joint disease Most common noninflammatory joint disease of movable joints Most often involves hips, knees, and lumbar spine Localized tenderness, morning stiffness, and pain from movement Bouchard’s or Heberden’s nodes may also be present on the fingers

Noninflammatory Joint Disease Dislocation- joint becomes “out of place” Subluxation- dislocation occurs but goes back in on its own Sprain- ligament injury Strain- tendon or muscle injury Avulsion Fracture Epiphyseal Fracture

Inflammatory Joint Disease Arthritis Can be caused by infection, injury, genetic factors, and autoimmunity There are 3 major types of arthritis…

Arthritis Rheumatoid Gouty Infectious Chronic inflammation caused by an autoimmune disease Deformity in hands, fatigue, and other autoimmune diseases are common May occur in children Gouty Metabolic condition forms crystals in the joints Infectious Pathogens infect synovial membrane and other joint tissues

Types of Motion 􀂃 FLEXION- decreasing angle 􀂃 EXTENSION- increasing angle 􀂃 ABDUCTION- moving away 􀂃 ADDUCTION- moving towards 􀂃 CIRCUMDUCTION- moving in a circle 􀂃 ROTATION- turning on an axis 􀂃 PRONATION- turning palm down 􀂃 SUPINATION- turning palm up