Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 Organization and Regulation of Body Systems 4-1

4.1 Types of Tissues A tissue is composed of specialized cells of the same type that perform a common function. *Four primary tissues make up the body: A. Connective tissue—binds and supports the body. B. Muscle tissue—moves the body and its parts. C. Nervous tissue—receives stimuli and conducts nerve impulses. D. Epithelial tissue—covers body surfaces and lines the cavities of the body. 4-2

4.1 Types of Tissues Cancers are classified according to the type of tissue from which they arise: a.Sarcomas—cancers of bone and cartilage. b.Leukemia—cancers of the blood. c.Lymphomas—cancers of the lymphoid tissue. d.Carcinomas—cancers of the epithelial tissue. 4-3

4.1 Types of Tissues A. Connective Tissues: Fibrous Connective tissue: *Loose fibrous connective tissue—supports epithelium and many internal organs. *Adipose tissue—a type of loose connective tissue with large cells that store fat. *Dense fibrous connective tissue—contains many collagen fibers like tendons and ligaments. 4-4

4.1 Types of Tissues Connective Tissues cont. Supportive Connective tissue: * Hyaline cartilage—has a white translucent appearance and found in the nose & ends of long bones. * Elastic cartilage—more flexible & found in the outer ear. * Fibrocartilage—found between the vertebrae in the backbone. 4-5

4.1 Types of Tissues Connective Tissues cont. Bone—rigid connective tissue. *Compact bone—hard mineralized matrix that gives strength to bone. *Spongy bone—large spaces filled with red marrow. 4-6

4.1 Types of Tissues Connective Tissues cont. Fluid connective tissue: *Blood—consists of formed elements and plasma. *Tissue fluid (lymph)—plays a role in fluid, ion, and pH balance within the body. *RBC—transports oxygen to body cells. *WBC—fight infection, some are phagocytic and others combine with foreign substances to inactive them. *Platelets—cell fragments necessary for clotting of the blood. 4-7

4.1 Types of Tissues B. Muscle Tissues: *Skeletal muscle— voluntary muscles attached to the bones. *Smooth muscle— involuntary muscles making up the walls of the internal organs. *Cardiac muscle— involuntary muscles found only in the heart. 4-8

4.1 Types of Tissues C. Nervous tissue—sensory input, integration of data, and motor output. *Neuron—nerve cell made up of dendrites, a cell body, and an axon. *Neuroglia—cells that support and nourish neurons. a. Microglia—engulf bacterial & cellular debris. b. Astrocytes—provide nutrients to neurons. c. Oligodendrocytes—form myelin, which speed impulse transmission. 4-9

4.1 Types of Tissues D. Epithelial tissue: *Simple epithelia—a single layer of cells classified according to cell types. a. Squamous epithelium—flattened cells forming the lining of blood vessels and alveoli. b. Cuboidal epithelium—cubed shaped cells lining the kidney tubules and glands. c. Columnar epithelium—rectangular cells in columns lining the digestive tract. *Stratified epithelia—layers of cells piled one on top of the other (lining the nose, mouth, & esophagus). *Glandular epithelia—secretes products like mucus, digestive enzymes, and hormones. 4-10

4.1 Types of Tissues 4-11

4.2 Integumentary System Integumentary system—made up of the skin, hair, nails, sweat glands, and sebaceous glands. *Epidermis—stratified squamous epithelium composed of keratinocytes and melanocytes. *Dermis—dense fibrous connective tissue containing sensory receptors, blood vessels, & glands. *Subcutaneous layer—loose connective tissue and adipose tissue, which stores fat. 4-12

4.2 Integumentary System 4-13

4.2 Integumentary System Accessory Organs of the Skin: *Nails—sheets of hard keratinized cells forming a protective covering for the fingers and toes. *Hair follicles—found in the dermis and where sebum is released to lubricate the hair. *Sweat glands—play a role in modifying body temperature and have ducts that lead to a pore at the surface of the skin. *Oil glands—secrete sebum, an oily substance that lubricates the skin and hair. 4-14

4.3 Organ Systems A. Organ Systems: Integumentary System—largest single organ of the body that has a protective function, synthesizes vitamin D, collects sensory data, and helps regulate body temperature. Cardiovascular System—transports nutrients & O 2 to cells and transports wastes away from cells; also defends against disease. Lymphatic System—immunity, defends against disease, absorbs fats, & drainage of tissue fluid. Digestive System—ingestion & digestion of food, absorbs nutrients and eliminates waste materials. 4-15

4.3 Organ Systems Respiratory System—gaseous exchange at lungs & tissues and helps control pH balance. Urinary System—eliminates metabolic wastes and helps control fluid & pH balance. Skeletal System—internal support & protection and production of blood cells. Muscular System—moves body & internal organs and produces body heat. Nervous System—receives sensory input, integrates, & initiates motor output. Endocrine System—produces hormones for regulation of body tissues. Reproductive System—production of gametes & sex hormones and nurtures offspring. 4-16

4.3 Organ Systems B. Body Cavities: 1. Ventral body cavity (coelom)—largest cavity located on the front side of the body. a. Thoracic cavity—encloses & protects the heart and lungs Diaphragm (breathing muscle) b. Abdominal cavity—below the diaphragm and encloses the stomach, liver, spleen, intestines, reproductive organs, and urinary organs. 2. Dorsal body cavity—smallest cavity located on the backside of the body. a. Cranial cavity—protects the brain. b. Vertebral cavity—protects the spinal cord. 4-17

4.3 Organ Systems 4-18

4.3 Organ Systems C. Body Membranes: 1. Mucous membranes—line body cavities that open DIRECTLY to the outside of the body. ex. Tubes of the digestive, respiratory, urinary, and reproductive systems. **Goblet cells—secrete mucus for protection & keeps membranes from drying out. 2. Serous membranes—line body cavities that DO NOT open directly to the outside of the body. ex. Thoracic and abdominal cavities. **Serous fluid—lubricates and reduces friction between moving layers of tissue. Peritonitis—inflammation of the peritoneum. 4-19

4.3 Organ Systems Body Membranes cont. 3. Synovial membranes—line movable joint cavities of the skeleton. ex. Ball-&-socket joints, hinge joints, & pivot joint. **Synovial fluid—lubricates the ends of long bones so that they can move freely. Rheumatoid Arthritis—synovial membrane becomes inflamed and grows thicker, restricting movement. 4-20

4.4 Homeostasis Homoestasis—relative constancy of the body’s internal environment. A. Two parts of the internal environment: 1. Blood—delivers O 2 and nutrients to the tissues and carries CO 2 & wastes away. 2. Tissue fluid—medium through which substances are exchanged between cells and blood. B. All systems of the body contribute to homeostasis but especially: 1. The nervous system is able to bring about rapid responses to any changes in the internal environment. 2. The endocrine glands brings about responses that are slower to occur but have lasting effects. 4-21

4.4 Homeostasis Human Systems Work Together 4-22

4.4 Homeostasis C. Negative feedback—primary homeostatic mechanism that keeps everything at normal levels. 1. Two components at work: a. Sensory component—detects a change in the internal environment. b. Control center—brings about an effect to return conditions back to normal again. ex. Regulation of body temperature. 4-23

4.4 Homeostasis 4-24

4.4 Homeostasis D. Positive feedback—a mechanism that brings about an ever greater change in the same direction. * Positive feedback mechanisms are useful under certain conditions, such as during birth. * Positive feedback mechanism can be harmful, as when a fever causes metabolic changes that push the fever still higher. 4-25