Transcript Chapter 17
Chapter 17 Structure and Movement Section 1- The Skeletal System • All the bones in your body make up your skeletal system. • 5 Major Functions. – 1. Gives shape and support to your body. – 2. Protects your internal organs. Ex. Skull encloses the brain. – 3. Major muscle are attached to bone and help them move. – 4. Blood cell formation – 5. Stores minerals Bone Structure • Periosteum – Tight-fitting membrane that makes up outer covering of bone. – Under the periosteum are compact and spongy bone. • Compact bone – Directly underneath periosteum – Gives bones strength • Spongy bone – Found on the ends of bone – Makes bone lightweight • Cartilage – Flexible tissue without blood cells that cushions ends of bones. Bone Formation • Osteoblasts- build up bone. • Osteoclasts- breaks down bone tissue. • Marrow – Substance that produces red and white blood cells inside bones. Joints • Joint – Where two or more bones meet. • The bones are held in place at these joints by a tough band of tissue called a ligament. • Immovable Joint – Allows little or no movement – Ex. Skull and Pelvis • Movable Joint – – – – Joint that allows range of movement. Ex. Ball and socket, pivot, hinge Ball and socket- attaches your arm and shoulder. http://glencoe.mcgrawhill.com/sites/0078617022/student_view0/brainpop_movie s.html# Section 2- The Muscular System • Muscle – Organ that contracts and relaxes. Makes all your daily movements possible. • MORE THAN 600 MUSCLES MAKE MOVEMENT POSSIBLE!!!!! • Tendons – Thick bands of tissue that attach muscle to bone. • Voluntary Muscles – Muscles that you are able to control – Ex. Arm, Hand, and Leg • Involuntary Muscles – Muscles you can’t control consciously – Blood moves through blood vessels – Food is moved through your digestive system Classification of Muscle Tissue • Three types of Muscle: – 1. Skeletal – 2. Smooth – 3. Cardiac • Skeletal – Muscles that look striped and are used to move bones. Always work in pairs. When on contracts the other relaxes. • Smooth – Involuntary muscles that have NO striations • Cardiac – Involuntary muscles with straitions in your heart. Section 3- The Skin • The LARGEST organ in your body!!!! • Epidermis – Outermost layer of your skin. (thinnest) – Cells of the epidermis are constantly rubbing off, being replaced, and dying off. • What pigment gives the skin color?? – Melanin! – Exposure to ultraviolet rays, increases melanin production. • Dermis – Layer of tissue under the epidermis. – Contains blood vessels, nerves, muscles, oil and Skin Functions • Skin Protects Your Body: – 1. Prevents internal damage (injury) – 2. Prevents excess water loss from body tissues – 3. Glands secrete fluids that destroy bacteria – 4. Formation of vitamin D. – 5. Regulates body temperature • Sweat glands help rid the body of wastes by releasing water and salt. • Skin Grafts – pieces of skin that are cut from one part of a person’s body and then moved to the injured or burned area where there is no skin.