Chapter 6
Skeletal System
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Functions
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Support
Protect
Movement and anchorage
Mineral storage
hemopoiesis
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Structure and Formation of Bone
• Osteocytes
– Mature bone cell
• Organic material (flexibility)
– Collagen
– Jellylike material
• Inorganic material (hardness and durability)
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Long Bones
• Shaft or diaphysis
• Each end is the epiphysis
– Covered by articular cartilage
• In center is the medullary canal
– Yellow bone marrow
– Endosteum (lining of the marrow canal)
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Long Bones
• Red marrow
– Ends of long bones
– Manufacture red blood cells and some white blood cells
• Periosteum
– Covering on outside of the bone
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Growth
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Grow in length
Ossify from center outward
Osteoblasts
Osteoclasts
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Growth
• Growth stops when all the epiphyseal
cartilage is ossified
• Females grow until about 18 years of age
• Males grow until about 20-21 years of age
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Bone Types
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Long bones
Flat bones
Irregular bones
Short bones
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Skeletal System
• Axial skeleton
– Skull, spinal column, ribs, sternum, and hyoid bone
• Appendicular skeleton
– Upper and lower extremities
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Axial Skeleton
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22 bones of the skull
14 facial bones
Spinal column (vertebra)
Ribs and sternum
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The Skull
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The Skull
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Appendicular Skeleton
Upper Extremities
• Shoulder girdle
• Arm
• Hand
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Appendicular Skeleton
Lower Extremities
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Pelvic girdle
Upper leg
Lower leg
Ankle
Foot
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Joints
• Called articulations
– Points of contact between two bones
• Diarthroses (moveable) joints
• Amphiarthroses (partially movable) joints
• Synarthroses (immovable) joints
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Joints
• Articular cartilage
• Articular capsule
– Synovial membrane
– Synovial fluid
– Synovial cavity
• Bursa sacs
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Diarthroses Joints
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Movable joints
Ball-and-socket joints
Hinge joints
Pivot joints
Gliding joints
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Animation – Types of Joints
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Types of Joints animation
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Amphiarathroses Joints
• Partially movable joints
• Cartilage between their articular surfaces
• Examples:
– Ribs to the spine
– Symphysis pubis
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Synarthroses Joints
• Immovable joints
• Connects by tough, fibrous connective tissue
• Example:
– Adult cranium
• Cranial joints called sutures
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Types of Motion
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Flexion
Extension
Abduction
Adduction
Circumduction
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Types of Motion
• Rotation
• Promation
• Supination
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Aging
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Bone mass and density decline
External surfaces of bones thicken
Intervertebral cartilage disks shrink
Center of balance is altered
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Aging
• Joints less mobile
• Increased rigidity and decreased flexibility
• Fear of falling
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Disorders of the Bones and Joints
• Fracture
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Greenstick
Closed/simple
Open/compound
Comminuted
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Animation – Types of Fractures
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Fractures animation
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Repairing Fractures
• Closed reduction
• Open reduction
• Traction
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Bone and Joint Injuries
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Dislocation
Sprain
Hammer Toe
RICE
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Diseases
• Arthritis
– Rheumatoid arthritis
– Osteoarthritis
• Gout
• Rickets
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Diseases
• Slipped (herniated) disc
• Whiplash injury
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Abnormal Curvatures of the Spine
• Kyphosis (hunchback)
• Lordosis (swayback)
• Scoliosis
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Other Disorders
• Osteoporosis
• Osteomyelitis
• Osteosarcoma
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