Skeletal, Muscular, and I ntegumentary Systems

1. Skeletal, Muscular, and Integumentary Systems By: Lauren Reyner, Brittany Mindt, Dominique DiBernardo

2. Important Vocabulary • Axial Skeleton- supports the central axis of the body • Appendicular Skeleton- Formed by the bones of the arms and legs, along with the bones of the pelvis and shoulder area • Haversian Canals- Compact bone in channels in which nerves and blood vessels run through • Bone marrow- cavities that contain a soft tissue • Cartilage- type of connective tissue • Ossification- Process of bone formation in which cartilage is replaced by bone. • Osteoblasts- secrete mineral deposits that replace the cartilage in developing bones • Osteoclasts- cells that break down bone minerals • Ligaments- tough connective tissue that is attached to the membranes that surround bones.

3. The Skeletal System • Functions: • Supports the body • Protects internal organs • Assists movement • Stores minerals • Blood cell formation • Disorders: • - Arthritis- Inflammation of a joint • - Osteoporosis- Loss of calcium leads to weakening of bones

4. Components of the Skeleton • Made of approximately 206 bones • Bones attached to muscle by tendons • Bones held together by Ligaments

5. Bones • Bones are a solid network of living cells and protein fibers that are surrounded by deposits of calcium salts. • The skeleton of a human embryo is composed almost entirely of cartilage. • Spongy Bone- can support a lot of force and red bone marrow is found in the spaces of spongy bone. • Compact bone- Found under the periosteum, contains networks of tubes through which blood vessels and nerves travel. • Yellow marrow- mainly made of fat cells • Red Marrow- Produces blood cells

6. Joints • Joint- a place where one or more bones meet another bone • Joints contain connective tissues that hold bones together • Joints permit bones to move without damaging each other. • Types of Joints: • Immovable(fixed Joints)- Allow no movement. Joints are interlocked and fuse together ex. Skull • Slightly Movable- allow small amount of movement ex. Lower leg • Freely Movable- allow movement in two or more directions • Wear and tear over the years leads to osteoarthritis

7. The Muscular System • Muscle- Bundles of fibers that work together to allow for structure and movement • 3 types: • Skeletal- Attaches to bones and moves them. Voluntary. • Smooth- Controls breathing and digestive system. Involuntary. • Cardiac- Found only in the heart. Involuntary.

8. Important Vocabulary • Myofibrils- tightly packed filament bundles • Myosin- thick filaments of protein • Actin- thin filaments of protein • Sarcomere- two Z lines and filaments between them • Neuromuscular Junction- a synapse • Acetylocholine- neurotransmitter • Tendons- connective tissue that join skeletal muscles and bone

9. Muscle Contraction • During a muscle contraction, myosin filaments form cross-bridges with actin filaments. The cross-bridges then change shape, pulling actin filaments towards the center of the sarcomere.

10. Muscle Movement • Skeletal muscles generate force and produce movement by pulling the body parts as they contract • Flexor- Decrease angle between bones (biceps) • Extensor- Increase angle between bones (Triceps) • Muscles work together- One contracts while the other relaxes

11. Integumentary System • The Integumentary system serves as a barrier against infection and injury, helps to regulate body temperature, removes wastes from the body, gathers information, and produces vitamin D

12. Different Layers of Skin • Epidermis- Outer Layer • Inner layer- Living cells • Outer layer- Dead cells • Contains: • Keratin- Waterproofing • Melanocytes- produces pigment

13. Different Layers of Skin • Dermis- Middle layer- Irregular ridges between dermis and epidermis form fingerprints • Contains: • Hair follicles/Roots • Sweat glands • Sebacious(oil) glands • Arrector pili Muscle • Nerves • Blood vessels

14. Different Layers of Skin • Hypodermis- Innermost layer • Contains: • Adipose(fat) cells- Cushions, insolates • Blood Vessels- Temperature regulation, nutrients • Nerves- Pressure, pain

15. Skin Problems • Acne- Develops when sebum and dead skin cells form plugs in hair follicles • Hives- allergic reactions to food or medicine • Skin Cancer- excessive exposure to the ultraviolet radiation in sunlight