Chapter 6 Skeletal System 2009 Delmar Cengage Learning

Chapter 6 Skeletal System © 2009 Delmar, Cengage Learning

Functions • Support • Protect • Movement and anchorage – Ligaments are fibrous bands that connect bones to bones and cartilage and serve as support for muscles – Tendons are fibrous cords that connect muscles to bone • 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

Bone Formation • Embryonic skeleton initially consists of collagenous protein fibers secreted by osteoblasts • 8 th week of embryonic development, ossification begins – Mineral matter starts to replace previously formed cartilage, creating bone © 2009 Delmar, Cengage Learning

© 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) • Red marrow – Ends of long bones – Manufacture some red blood cells and some white blood cells • Periosteum – Covering on outside of the bone © 2009 Delmar, Cengage Learning

© 2009 Delmar, Cengage Learning

Growth • • • Grow in length Ossify from center outward Osteoblasts Osteoclasts 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

© 2009 Delmar, Cengage Learning

Types of Bones • • Long Flat Short Irregular © 2009 Delmar, Cengage Learning

© 2009 Delmar, Cengage Learning

Axial Skeleton • Skull • Ribs and Sternum • Spinal Column and Vertebrae © 2009 Delmar, Cengage Learning

Axial Skeleton u. Skull • Cranium houses and protects the delicate brain, while the facial bones guard and support the eyes, ears, nose and mouth • Collectively there are 22 bones in the skull © 2009 Delmar, Cengage Learning

The Skull © 2009 Delmar, Cengage Learning

The Skull © 2009 Delmar, Cengage Learning

Ribs and Sternum u. Ribs and sternum • 12 pairs of ribs • Sternum or breastbone divided into 3 parts © 2009 Delmar, Cengage Learning

Spinal Column/Vertebrae u. Spinal column/vertebrae • Spine consists of small bones called vertebrae which are separated from each other by pads of cartilage tissue called intervertebral disks • Five sections: cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacrum and coccyx © 2009 Delmar, Cengage Learning

© 2009 Delmar, Cengage Learning

© 2009 Delmar, Cengage Learning

APPENDICULAR SKELETON Upper Extremities • Shoulder Girdle • Arms • Hand © 2009 Delmar, Cengage Learning

Shoulder Girdle • 2 clavicles (collar bones) • 2 scapulae (shoulder bones) © 2009 Delmar, Cengage Learning

Arms • Humerus • Radius • Ulna © 2009 Delmar, Cengage Learning

Hand • 8 carpals (wrist bones) • 5 metacarpals (hand bones) • 14 phalanges (finger bones) © 2009 Delmar, Cengage Learning

Skeletal System • Appendicular skeleton (lower extremities) – Pelvic girdle • Ilium, Ischium and Pubis – Legs • Femur (thigh bone) • Tibia and Fibula • Patella (kneecap) – Ankle • 7 tarsal bones • Calcaneus (heel bone) – Foot • 5 metatarsal bones (foot bones) • 14 phalanges (toe bones) © 2009 Delmar, Cengage Learning

Joints • Called articulations – Points of contact between two bones • Diarthroses (movable) joints • Amphiarthroses (partially movable) joints • Synarthroses (immovable) joints © 2009 Delmar, Cengage Learning

Diarthroses Joints • Movable joints consist of three main parts – Articular cartilage – Articular capsule – Synovial membrane – Synovial fluid – Synovial cavity – Bursa sacs • 4 types of diarthroses – – Ball-and-socket joints Hinge joints Pivot joints Gliding joints © 2009 Delmar, Cengage Learning

© 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

© 2009 Delmar, Cengage Learning

Synarthroses Joints • Immovable joints • Connected by tough, fibrous connective tissue • Example: – Adult cranium • Cranial joints called sutures © 2009 Delmar, Cengage Learning

© 2009 Delmar, Cengage Learning

Types of Motion • • Flexion Extension Abduction Adduction Circumduction Rotation Pronation Supination © 2009 Delmar, Cengage Learning