1. Skeletal, Muscular, and Integumentary Systems
Chapter 36: Biology II

2. The Skeleton Supports the body Protects internal organs
Provides for movement
Stores mineral reserves
Provides a site for blood cell formation
Humans have 206 bones!!!

3. The Axial Skeleton Supports the central axis of the body
Skull, vertebral column and rib cage

4. The Appendicular Skeleton
Arms and legs, pelvis and shoulder area

5. Structure of Bones Solid networks of living cells and protein fibers
Surrounded by deposits of calcium salts

6. Periosteum
Tough layer of connective tissue surrounding a bone

7. Haversian Canal
One of a network of tubes running through compact bone that contains blood vessels and nerves

8. Bone Marrow Soft tissue inside cavities within bones Yellow Marrow
Fat cells
Red Marrow
Red blood cells, white blood cells, platelets

9. Development of Bones
Skeleton of a newborn baby is almost entirely cartilage
Cartilage: strong connective tissue that supports the body and is softer and more flexible than bone; does not contain blood vessels

10. Ossification
Process of bone formation, during which cartilage is replaced by bone

11. Joint
A place where one bone attaches to another bone

12. Types of Joints Immovable/Fixed Joints: skull bones
Slightly movable: bones of lower leg, between adjacent vertebrae
Freely movable: movement in one or more directions

13. Freely Moveable Joints
Ball-and-socket: circular movement
Hinge: back and forth movement

14. Freely Moveable Joints
Pivot: rotation of one bone around another
Saddle: one bone can slide in two directions

15. Structure of Freely Movable Joints
Ligament: strip of tough connective tissue in a joint that holds bones together

16. Structure of Freely Movable Joints
Synovial fluid: a substance which forms a thin film within the bone surfaces of a joint
Enables the ends of the bones to slip past each other more smoothly

17. Structure of Freely Movable Joints
Bursae: small sacs of synovial fluid that form in some freely-movable joints
Reduce the friction between bones of a joint and act as a tiny shock absorber
Bursitis: inflammation of bursa; too much fluid fills the bursa, causing painful swelling…more serious  arthritis

19. The Muscle System
A skeleton cannot move by itself!

20. The Muscle System
Muscles provide the forces that put the body into motion
More than 40% of the mass of the average human body is muscle

21. Types of Muscle
Skeletal: attached to bones, responsible for voluntary movements
Smooth: responsible for most involuntary movements
Cardiac: found in the heart

22. Muscle Contraction
Myofibrils: small structures that make up the muscle fibers in skeletal muscles
Myosin: protein that makes up the thick filaments in striations in skeletal muscle cells

23. Muscle Contraction
Actin: a protein that mainly makes up the thin filaments in striations in skeletal muscle cells
A muscle contracts when the actin filaments slide over the myosin filaments
Energy for muscle contraction is supplied by ATP

24. Muscle Contraction