Skeletal System Skeletal System 206 bones Functions n

Skeletal System

Skeletal System 206 bones Functions n n 1. 2. 3. 4. 5. Supports body and provides shape Protects internal organs Movement and anchorage of muscles Mineral storage (Calcium and Phosphorus) Hemopoiesis (red marrow of the bone is the site of blood cell formation – red marrow is in long bones (epiphyses), sternum and ilia).

Bone formation Osteocytes = mature bone cell Osteo = bone Cyte = cell Microscopic mature bone cells 1. 02 Remember the structures of the skeletal system 3

Bone formation n Ossification – new minerals deposit to form bone n Begins at 8 weeks gestation n Minerals replace previously formed cartilage. 1. 02 Remember the structures of the skeletal system 4

Bone formation n Infants bones are soft and pliable because of incomplete ossification. As bones ossify, they become hard. Long bones grow in length and ossify from the center to the ends. 1. 02 Remember the structures of the skeletal system 5

Know the following…. n n n Osteocytes = mature bone cells Osteoblasts = cells that actually form bone Osteoclasts = cells that tear down old bone 1. 02 Remember the structures of the skeletal system 6

Types of Bones Long bones Found in the arms and legs Diaphysis – shaft Epiphyses – ends Periosteum – outer covering of bone Medullary cavity – center of shaft, filled with yellow marrow, mostly fatty cells, also cells that form white blood cells Endosteum - lines marrow cavity 7

n n Shaft or diaphysis is made of compact bone (DENSE) the ends are spongy bone (POROUS). Ends contain red marrow where red blood cells are made. Periosteum – tough, outside covering of bone – contains blood vessels, lymph vessels, and nerves 1. 02 Remember the structures of the skeletal system 8

1. 02 Remember the structures of the skeletal system 9

Ribs n n n 7 pairs of costal cartilages join seven pairs of ribs directly to sternum = true ribs 3 pairs of false ribs …cartilage joins ribs to other ribs 2 pairs of floating ribs 1. 02 Remember the structures of the skeletal system 10

Chewing with movable skull bone = mandible The central opening on the vertebrae for passage of the spinal cord is the foramen at the base of the occipital skull bone

1. 02 Remember the structures of the skeletal system 13

Axial – skull, spinal column, ribs, sternum, hyoid (tip of sternum = xiphoid process) (u-shaped bone in neck to which the tongue is attached) n n Appendicular – shoulder girdle, arms, pelvis, legs (126 bones total) 1. 02 Remember the structures of the skeletal system 14

Axial Skelton n n Hyoid Bone What is unique about the hyoid bone? 1. 02 Remember the structures of the skeletal system 15

Vertebral Column

Spine – Vertebral Column n n Encloses the spinal cord Vertebrae – separated by pads of cartilage n n Cervical Vertebrae (7) n n n Intervertebral discs Atlas – 1 st cervical vertebrae Axis – 2 nd cervical vertebrae Thoracic Vertebrae (12) Lumbar Vertebrae (5) Sacrum Coccyx

Appendicular Skeleton n n Shoulder girdle Clavicle, scapula, humerus 1. 02 Remember the structures of the skeletal system 18

Appendicular skeleton n Clavicle = collar bone n Scapula = shoulder blade n Humerus = upper arm n n Radius and ulna = lower arm (radius = thumb side, ulna=pinky side) Carpals = wrist bones held together by ligaments

n Metacarpals = hand bones n Phalanges = finger bones n Pelvis = 3 bones (ilium, ischium, and pubis) n Femur = upper leg, longest and strongest bone in the body 1. 02 Remember the structures of the skeletal system 20

n Tibia and Fibula = lower leg (tibias touch – tibia is larger of the two bones) n Sternum = breast bone n Patella = kneecap n Tarsal bones = ankle bones n Calcaneus = heel bone n Metatarsals = foot bones

Appendicular Skeleton n n Pelvis Pelvic girdle = ilium, ischium and pubis 1. 02 Remember the structures of the skeletal system 22

Joints n Joints are points of contact between 2 bones - classified according to movement: n n n Diarthrosis – movable Amphiarthrosis – partially movable Synarthrosis – immovable (skull) Articular cartilage – covers joint surface Synovial Fluid – lubricating substance in joints

1. 02 Remember the structures of the skeletal system 24

Joints n Ball and socket n n One bone has a ball at one end The other has a concave socket Allows for the greatest range of motion Ex: shoulder, hip 1. 02 Remember the structures of the skeletal system 25

Joints n Hinge joint n Move in one direction 1. 02 Remember the structures of the skeletal system 26

Joints: Diarthroses n n Example of a hinge joint. Define uniaxial… permits movement in one direction (axis) only 1. 02 Remember the structures of the skeletal system 27

Joints n Pivot joints n Bones that rotate across each other 1. 02 Remember the structures of the skeletal system 28

Joints n Gliding joint n n Bones with flat surfaces that slide across each other i. e. bones in ankle and hand 1. 02 Remember the structures of the skeletal system 29

Joints n Amphiarthroses n Partially movable joints 1. 02 Remember the structures of the skeletal system 30

Joints n Synarthroses n n Immovable joints…found in adult cranium Connected by fibrous connective tissue 1. 02 Remember the structures of the skeletal system 31

Bursa and Synovial Membrane n Bursa n n n Fluid-filled sac that contains the synovial membrane Lined by synovial membrane Bursitis = inflammation of the bursa 1. 02 Remember the structures of the skeletal system 32

Bursa and Synovial Membrane n Synovial membrane n Capsule that encloses a joint n n Lines the bursa Contains synovial fluid 1. 02 Remember the structures of the skeletal system 33

Types of movement n Flexion is a position that is made possible by the joint angle decreasing…. bending

Extension A movement of a joint in which one part of the body is moved away from another. i. e. going from sitting to standing

n Abduction n Adduction A motion that pulls a structure or part away the midline of the body. A motion that pulls a structure or part towards the midline of the body

Circumduction n The circular or a more precise movement of a body part, such as a ball-andsocket joint or the eye.

Rotation n A motion that occurs when a part turns on its axis. i. e. shaking your head “no”

Pronation n A rotation of the forearm that moves the palm from an anteriorfacing position to a posterior-facing position, or palm facing down.

Supination n The opposite of pronation, the rotation of the forearm so that the palm faces anteriorly, or palm facing up.

Disorders of the Skeletal System n n n Osteomyelitis – Infection in the bone Arthritis = An inflammation of one or more joints. Osteoarthritis- degenerative, occurs with aging, 80% of Americans suffer, joints become enlarged and painful 41

Disorders of the Skeletal System n Arthritis n Rheumatoid arthritis = A chronic, autoimmune disease = joints become swollen and painful, joint deformities common 1. 03 Understand the functions and disorders of the skeletal system 42

Rheumatoid arthritis Osteoarthritis

Strain Damage to tendon Sprain sudden or unusual motion, ligament is torn but joint is not dislocated 1. 02 Remember the structures of the skeletal system 44

Disorders of the Skeletal System n n Gout Increase of uric acid deposited in joint cavity, mostly the great toe in men. 1. 03 Understand the functions and disorders of the skeletal system 45

Disorders of the Skeletal System n n Osteoporosis- most of those affected are women. Mineral density of bone is reduced 35% – 65%. The loss of bone mass leaves the bone thinner, more porous and more prone to fracture. (soft like a sponge) 46

47

Disorders of the Skeletal System n Rickets n n Found in children, caused by lack of vitamin D, bones become soft. Is this a common problem in the US? Why or why not? No rm al l egs 48

Disorders of the Skeletal System n Abnormal spinal curvatures Kyphosis nchback hu Lordosis ck s ba way 1. 03 Understand the functions and disorders of the skeletal system Scoliosis 49

Skeletal System Trauma n Dislocation n n Separation of bones in a joint Subluxation = partial separation (dislocation) 1. 03 Understand the functions and disorders of the skeletal system 50

Skeletal System Trauma n n Fracture- a break in a bone Treated by: n Closed reduction- cast or splint applied…to immobilize the bone n Open reduction- surgical intervention with devices such as wired, metal plates or screws to hold bone in alignment n Traction- pulling force used to hold the bone in place n Used for fractures of long bones 51

n Closed or simple n n Open or compound n n in children, bone bent and splintered but never completely separates Comminuted n n broken bone pierce the skin, can lead to infection Greenstick n n bone broken, broken ends don’t break skin splintered or broken into many pieces Spiral n bone twists, resulting in one or more breaks 52