Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Unit 10 The Human Body Ch. 36 Skeletal, Muscular, & Integumentary System The Skeleton • The skeleton supports the body, • protects internal organs, provides for movement, stores mineral reserves, & provides a site for blood cell formation Bones provide a system of levers on which muscles act to produce movement The Skeleton • The skeleton supports • the body The human skeleton is divided into 2 parts: the axial skeleton, & the appendicular skeleton Structure of Bones • Bones are a solid network of living cells • & protein fibers that are surrounded by deposits of calcium salts Periosteum - tough layer of connective tissue that surrounds bone Structure of Bones • Haversian canals - found in dense, • compact bone, contains blood vessels & nerves Bone marrow - soft tissue found in bone cavities Yellow marrow - made of fat cells Red marrow - produces red blood cells, some white blood cells, & platelets Development of Bones • Cartilage - type of connective tissue that • does not have blood vessels, it is dense & fibrous & therefore, can support weight Ossification - process when cartilage is replaced by bone Types of Joints • Joint - a place where 1 bone attaches to • • another bone They permit bones to move without damaging each other Depending on its type of movement, a joint is classified as immovable, slightly moveable, or freely moveable Types of Joints • Freely movable joints are classified by the type of movement they permit Structure of Joints • Cartilage covers the surfaces where 2 • • bones come together Ligaments - link bone-tobone in a joint Tendons - tie muscle-tobone in a joint Skeletal System Disorders • Excessive strain on a joint may produce • • inflammation, where excess fluid causes swelling, pain, heat, & redness Arthritis is inflammation of the joint itself Osteoporosis is a loss of calcium in the bones, can cause serious fractures, typically occurs in older women Types of Muscle Tissue • There are 3 different types of muscle • • tissue: skeletal, smooth, & cardiac Skeletal muscles have stripes, & many nuclei Smooth muscle cells are spindleshaped & have 1 nucleus Types of Muscle Tissue • Cardiac muscle cells have stripes & only 1 nucleus Skeletal Muscle Structure How Muscles & Bones Interact • Tendons are attached so they pull on • the bones when the muscles contract Most skeletal muscles work in opposing pairs, when 1 contracts, the other relaxes Exercise & Health • Regular exercise is important in • • maintaining muscular strength & flexibility Aerobic exercises cause the body’s systems to become more efficient Resistance exercises increase muscle size & strength The Integumentary System • The integumentary system serves as a barrier against infection & injury, helps regulate body temp., removes waste products from the body, & provides protection against UV radiation from the sun The Skin • The largest component of the • integumentary system is the skin It contains many sensory receptors, therefore, it serves as gateway through which sensations like pressure, heat, cold, & pain, are transmitted to the nervous system The Skin • After strenuous exercise, the skin produces sweat, which decreases the temperature of the body & rids the body of wastes Structure of The Skin The Skin • Epidermis - the outer layer of skin • Melanin - a dark brown pigment, it helps • protect the skin from damage by absorbing UV rays from the sun Dermis - the inner layer of the skin, contains blood vessels, nerve endings, glands, sensory receptors, smooth muscles, & hair follicles The Skin • Excessive exposure to UV radiation can • produce skin cancer, an abnormal growth of cells in the skin Protect yourself by wearing a hat, sunglasses, & sunscreen Hair & Nails • The basic structure of human hair & • nails is keratin, which is a protein Hair covers almost every exposed surface of the body, it serves as protection from the sun (head), & from dirt, viruses, & bacteria, from entering the body (nostrils, external ear canals, & eyelashes) Hair & Nails • Nails grow at an average rate of • 3mm/month, with fingernails growing 4 times more rapidly than toenails Nails protect the tips of fingers and toes (digits)