The Skeletal System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Skeletal System Parts of the skeletal system Bones (skeleton) Joints Cartilages Ligaments (bone to bone) Tendon (bone to muscle) Slide 5.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Functions of Bones Support of the body Protection of soft organs Movement due to attached skeletal muscles Storage of minerals and fats Blood cell formation Slide 5.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Human Body The skeleton has 206 bones Two types of bone tissue Compact bone Spongy bone Figure 5.2b Slide 5.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Structures of a Long Bone Periosteum Sharpey’s fibers Arteries Figure 5.2c Slide 5.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Changes in the Human Skeleton In embryos, the skeleton is cartilage During development, much of this cartilage is replaced by bone Cartilage remains in isolated areas Bridge of the nose Parts of ribs Joints Slide 5.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Bone Cells Osteocytes Osteoblasts Osteoclasts Mature bone cells Osteoblasts Bone-forming cells Osteoclasts Bone-destroying cells Break down bone matrix for remodeling and release of calcium Slide 5.15 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bone Fractures A break in a bone Types of bone fractures Closed (simple) fracture – break that does not penetrate the skin Open (compound) fracture – broken bone penetrates through the skin Bone fractures are treated by immobilization Realignment of the bone Slide 5.16 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Axial Skeleton Forms the longitudinal part of the body Divided into three parts Skull Vertebral column Bony thorax Slide 5.20a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Axial Skeleton Slide 5.20b Figure 5.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Skull Two sets of bones Bones are joined by sutures Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint Slide 5.21a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Fetal Skull The fetal skull is large compared to the infants total body length Figure 5.13 Slide 5.27a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Fetal Skull Fontanelles membranes connecting the cranial bones Allow the brain to grow Convert to bone within 24 months after birth Figure 5.13 Slide 5.27b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Vertebral Column Vertebrae separated by discs The spine has a normal curvature Figure 5.14 Slide 5.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Structure of a Typical Vertebrae Figure 5.16 Slide 5.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Bony Thorax Forms a cage to protect major organs Slide 5.31a Figure 5.19a Slide 5.31a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Bony Thorax Made-up of three parts Sternum Ribs Thoracic vertebrae Figure 5.19a Slide 5.31b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Appendicular Skeleton Limbs Pectoral girdle Pelvic girdle Slide 5.32a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Appendicular Skeleton Figure 5.6c Slide 5.32b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Pectoral (Shoulder) Girdle Composed of two bones Clavicle – collarbone Scapula – shoulder blade These bones allow the upper limb to have exceptionally free movement Slide 5.33 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Shoulder Girdle Figure 5.20a, b Slide 5.34a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Upper Limb The arm is formed by a single bone Humerus Figure 5.21a, b Slide 5.35a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Upper Limb The forearm has two bones Ulna Radius Figure 5.21c Slide 5.35b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Upper Limb The hand Carpals – wrist Metacarpals – palm Phalanges – fingers Figure 5.22 Slide 5.36 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Pelvic Girdle Hip bones The total weight of the upper body rests on the pelvis Protects several organs Reproductive organs Urinary bladder Part of the large intestine Slide 5.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Pelvis Slide 5.38a Figure 5.23a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Gender Differences of the Pelvis Figure 5.23c Slide 5.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Lower Limbs The thigh has one bone Femur – thigh bone Figure 5.35a, b Slide 5.40a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Lower Limbs The leg has two bones Tibia Fibula Figure 5.35c Slide 5.40b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the Lower Limbs The foot Tarsus – ankle Metatarsals – sole Phalanges – toes Figure 5.25 Slide 5.41 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Joints Articulations (Movement) of bones Functions of joints Hold bones together Allow for mobility Slide 5.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Structural Classification of Joints Immovable joints example – Bones in skull Slightly movable joints example – joints between vertebrae Freely Movable joints example – shoulder, knee Slide 5.45 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Movable Joints Figure 5.29a–c Slide 5.52a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Types of Movable Joints Figure 5.29d–f Slide 5.52b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Inflammatory Conditions Associated with Joints Bursitis – inflammation usually caused by a blow or friction Tendonitis – inflammation of tendon sheaths Arthritis – inflammatory or degenerative diseases of joints Over 100 different types The most widespread crippling disease in the United States Slide 5.53 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Clinical Forms of Arthritis Osteoarthritis Most common chronic arthritis Probably related to normal aging processes Rheumatoid arthritis An autoimmune disease – the immune system attacks the joints Symptoms begin with bilateral inflammation of certain joints Often leads to deformities Slide 5.54a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings