© 2009 Delmar, Cengage Learning

Chapter 6

Skeletal System

© 2009 Delmar, Cengage Learning

Functions

• Support

• Protect

• Movement and anchorage

• Mineral storage

• hemopoiesis

© 2009 Delmar, Cengage Learning

Structure and Formation of Bone

• Osteocytes– Mature bone cell

• Organic material (flexibility)– Collagen

– Jellylike material

• Inorganic material (hardness and durability)

© 2009 Delmar, Cengage Learning

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)

© 2009 Delmar, Cengage Learning

Long Bones

• Red marrow– Ends of long bones

– Manufacture red blood cells and some white blood cells

• Periosteum– Covering on outside of the bone

© 2009 Delmar, Cengage Learning

Growth

• Grow in length

• Ossify from center outward

• Osteoblasts

• Osteoclasts

© 2009 Delmar, Cengage Learning

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

© 2009 Delmar, Cengage Learning

Bone Types

• Long bones

• Flat bones

• Irregular bones

• Short bones

© 2009 Delmar, Cengage Learning

Skeletal System

• Axial skeleton– Skull, spinal column, ribs, sternum, and hyoid bone

• Appendicular skeleton– Upper and lower extremities

© 2009 Delmar, Cengage Learning

Axial Skeleton

• 22 bones of the skull

• 14 facial bones

• Spinal column (vertebra)

• Ribs and sternum

© 2009 Delmar, Cengage Learning

The Skull

© 2009 Delmar, Cengage Learning

The Skull

© 2009 Delmar, Cengage Learning

Appendicular SkeletonUpper Extremities

• Shoulder girdle

• Arm

• Hand

© 2009 Delmar, Cengage Learning

Appendicular SkeletonLower Extremities

• Pelvic girdle

• Upper leg

• Lower leg

• Ankle

• Foot

© 2009 Delmar, Cengage Learning

Joints

• Called articulations– Points of contact between two bones

• Diarthroses (moveable) joints

• Amphiarthroses (partially movable) joints

• Synarthroses (immovable) joints

© 2009 Delmar, Cengage Learning

Joints

• Articular cartilage

• Articular capsule– Synovial membrane

– Synovial fluid

– Synovial cavity

• Bursa sacs

© 2009 Delmar, Cengage Learning

Diarthroses Joints

• Movable joints

• Ball-and-socket joints

• Hinge joints

• Pivot joints

• Gliding joints

© 2009 Delmar, Cengage Learning

Animation – Types of Joints

Click Here to play

Types of Joints animation

© 2009 Delmar, Cengage Learning

Amphiarathroses Joints

• Partially movable joints

• Cartilage between their articular surfaces

• Examples: – Ribs to the spine

– Symphysis pubis

© 2009 Delmar, Cengage Learning

Synarthroses Joints

• Immovable joints

• Connects by tough, fibrous connective tissue

• Example:– Adult cranium

• Cranial joints called sutures

© 2009 Delmar, Cengage Learning

Types of Motion

• Flexion

• Extension

• Abduction

• Adduction

• Circumduction

© 2009 Delmar, Cengage Learning

Types of Motion

• Rotation

• Promation

• Supination

© 2009 Delmar, Cengage Learning

Aging

• Bone mass and density decline

• External surfaces of bones thicken

• Intervertebral cartilage disks shrink

• Center of balance is altered

© 2009 Delmar, Cengage Learning

Aging

• Joints less mobile

• Increased rigidity and decreased flexibility

• Fear of falling

© 2009 Delmar, Cengage Learning

Disorders of the Bones and Joints

• Fracture– Greenstick

– Closed/simple

– Open/compound

– Comminuted

© 2009 Delmar, Cengage Learning

Animation – Types of Fractures

Click Here to play Types of Fractures animation

© 2009 Delmar, Cengage Learning

Repairing Fractures

• Closed reduction

• Open reduction

• Traction

© 2009 Delmar, Cengage Learning

Bone and Joint Injuries

• Dislocation

• Sprain

• Hammer Toe

• RICE

© 2009 Delmar, Cengage Learning

Diseases

• Arthritis– Rheumatoid arthritis

– Osteoarthritis

• Gout

• Rickets

© 2009 Delmar, Cengage Learning

Diseases

• Slipped (herniated) disc

• Whiplash injury

© 2009 Delmar, Cengage Learning

Abnormal Curvatures of the Spine

• Kyphosis (hunchback)

• Lordosis (swayback)

• Scoliosis

© 2009 Delmar, Cengage Learning

Other Disorders

• Osteoporosis

• Osteomyelitis

• Osteosarcoma