Ch. 32 Skeletal, Muscular, and Integumentary Systems

1. By: Melissa Montes, AnnaliseCastner, and Jessica Roesgen Ch. 32 Skeletal, Muscular, and Integumentary Systems

2. 32.1 Skeletal System • The skeleton supports the body, protects internal organs, assists movements, stores minerals, and is a site of blood cell formation.

3. The Skeleton • There are 206 bones in the adult body. The 2 types of skeleton systems are • Axial skeleton: this supports the central axis of the body. It consist of the skull the vertebral column and the rib cage. • Appendicular skeleton: The bones of the arms, legs, pelvis, and shoulder area.

4. Bones • Bones are a solid network of living cells and protein fibers are surrounded by deposits of calcium salts. • Structure of bones • Nerves and blood vessels run through out compact bone in channels called Haversian canals.

5. Structure of Bones • Long bones are surrounded by a tough layer of connective tissue called periosteum. • Bones are cavities that contain a soft tissue called bone marrow. • Yellow marrow: contains mostly fat • Red marrow: produces blood cells

6. Development of bones • Cartilage: type of connective tissue that is soft, strong, and flexible that supports the body. • Ossification: process were cartilage is replaced by bone • Osteoblasts: secrete mineral deposits that replace cartilage in developing bones • Osteocytes: help maintain the minerals in bone tissue and continue to strengthen the growing bone • Osteoclasts: cells that break down bone minerals

7. Joints • Joints contain connective tissue that holds bone together. Joints permit bones to move without damaging each other • Types of Joints: • Immovable- cranium and sacrum • Semi-moveable- vertebrae • Freely moveable- ball and socket, pivot, hinge, and saddle.

8. Structure of Joints • Ligaments: hold bones together in a joint and are attached to the membrane that surround bones. • Bones are held together by ligaments

9. 32.2 Muscular system

10. Muscle Tissue • There are three different types of muscle tissue: • Skeletal- attaches to and moves bones; voluntary • Smooth- controls breathing, digestive system; involuntary • Cardiac- muscles only found in the heart; voluntary

11. Muscles and Movement • Muscles are joined to bones by connective tissues called tendons • Skeletal muscles generate force and produce movement by pulling on body parts as they contract • Muscles work in pairs, one contracts and the other relaxes • Flexor contracts when bone angle is decreased • Extensor contracts when angle between bones increases

12. 32. 3 Skin-The Integumentary System • The integumentary system serves as a barrier against infection and injury, helps to regulate body temperature, removes waste from the body, gathers information, and produces Vitamin D

13. Integumentary System Structures • Skin and its related structures-the hair, nails, and several types of glands-make up the integumentary system. • Epidermis: outer layer of the skin • Outer layer is dead skin, inner layer are living cells • Keratin: tough fiber that causes waterproofing • Melanocytes: cells that produce brown pigment called melanin

14. Dermis • The dermis lies beneath the epidermis and contains the protein collagen, blood vessels, nerve endings, glands, sensory receptors, and hair follicles. • Forms finger prints • Sebaceous glands: secrete an oily substance called sebem that is released at the surface of the skin

15. Skin Problems • Acne: develops when sebem and dead skin cells form plugs in hair follicles • Hives: Allergic reactions to food or medicine often display themselves as red welts. • Skin Cancer: Excessive exposure to ultra violet radiation in sunlight and artificial radiation from tanning beds can produce an abnormal growth of cells in the skin