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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
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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-to- bone in a joint • Tendons - tie muscle-to- bone 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 spindle-shaped & have 1 nucleus
Types of Muscle Tissue • Cardiac muscle cells have stripes & only 1 nucleus
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
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)