The Skeletal System

1. The Skeletal System

2. The Skeletal System • The skeletal system protects and supports the body. • Skeleton = Greek word meaning “a dried body” • Functions: • Provides shape • Provides support and protection • Allows movement • Stores minerals • Produces blood.

3. Bones • Bones are living tissues that can grow and repair themselves, Connective tissue. • Connective tissue provides support for your body and connects all its parts. • Types of Connective Tissue: • Bone – provides support and shape. • Blood – delivers food and oxygen to the cells and carries away wastes. • Fat – keeps the body warm, cushions structures and stores energy.

4. Formation of Bone • At birth humans have more than 300 bones. • As humans grow and develop, bones grow longer and fuse together. • By age 18 bones are completely ossified (hardened) and stop growing longer. • An average adult has 206 bones.

5. Cranium Mandible Clavicle Scapula Sternum Humerus Ribs Vertebral Column Pelvic Girdle Radius Ulna Carpals Metacarpals Phalanges Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges

6. Bone Composition • Bones are composed of three layer of connective tissue: • Periosteum – outermost layer • contains blood vessels that bring nutrients and oxygen to the bone. • Compact bone – dense layer of bone • consists of blood vessels, nerve cells, and living bone cells. • Spongy bone – located in the ends and middle of long bones. • Porous and lightweight but strong and supportive. • Contains bone marrow.

7. Bone Composition

8. Other Components of Bone Red Blood Cells White Blood Cells • Bone Marrow • Located inside the spongy bone. • 2 Types: • Red Marrow – produces red and white blood cells. • Produces 500 billion red blood cells per day! • Yellow Marrow – fat cells that store energy. Fat Fat

9. Other Components of Bone • Cartilage • Located between two adjoining bones. • Cushions bones from sudden jolts • Provides a slippery surface to reduce friction. Cartilage between Femur and Tibia Cartilage Cartilage

10. Bone Classification • 4 classifications of bone: Radius/ Ulna Tibia/ Fibula Fingers & Toes Femur Humerus Long Bones Short Bones

11. Bone Classification Vertebral Column Pelvic Girdle & Cranium Irregular Bones Flat Bones

12. Male vs. Female Pelvic Girdles Female Pelvic Girdle Male Pelvic Girdle

13. Joints • A place where two or more bones meet – Joint • 5 types: • Immovable Joints – NO movement • Cranium • Ball-and- Socket = widest range of movement • Shoulder and hip • Gliding – some movement in all directions • Wrist and ankles • Hinge – only back and forth • Elbow and knee • Pivot – one bone rotates around another • Forearm, neck

14. Joint Types Immovable Pivot Ball and Socket Hinge Gliding Knee - Hinge Hip - Ball and Socket

15. Tendons & Ligaments