Understanding Human Body Tissues: Epithelial and Connective Tissue

2. Chapter 8: Human Organization: Section 8.1 Chapter 9: Digestive System Chapter 10: Circulatory System and Lymphatic System Chapter 11: Respiratory System Chapter 12: Nervous System Chapter 13: Urinary System Chapter 14: Reproductive System UNIT B: Human Body Systems

3. UNIT B Chapter 8: Human Organization In this chapter, you will learn about how the systems in our bodies are connected and work together to maintain a relatively constant internal environment. Chapter 8: Human Organization • What situations might disrupt the internal state of the body? • How can alleviating stress improve your health and quality of life? TO PREVIOUS SLIDE

4. UNIT B Chapter 8: Human Organization Section 8.1 Tissues are composed of similarly specialized cells that perform a common function in the body. There are four major types of tissues in the human body: Epithelial tissue:covers body surfaces, lines body cavities Connective tissue: binds and supports body parts Muscular tissue: moves the body and its parts Nervous tissue: receives stimuli, processes information, conducts nerve impulses 8.1 Types of Tissues TO PREVIOUS SLIDE

5. UNIT B Chapter 8: Human Organization Section 8.1 Epithelial tissue (epithelium) consists of tightly packed cells that form a continuous layer. Functions of epithelial tissue: Covers surfaces and lines body cavities External surface: protects the body from injury, drying out, and invasion by microbes Internal surface: secretes mucus along the digestive tract, sweeps up impurities from the lungs by means of cilia, absorbs molecules from kidney tubules and the intestine through microvilli Epithelial Tissue TO PREVIOUS SLIDE

6. UNIT B Chapter 8: Human Organization Section 8.1 Structure of epithelial tissue: A basement membrane usually joins an epithelium to underlying connective tissue Epithelial tissue is classified according to the shape of the cell it is composed of and the number of layers in the tissue. Classification based on shape: Squamous epithelium: flattened cells Cuboidal epithelium: cube-shaped cells Columnar epithelium: rectangular-shaped cells TO PREVIOUS SLIDE

7. UNIT B Chapter 8: Human Organization Section 8.1 Classification based on number of layers in the tissue: Simple epithelium: single layer of cells Stratified epithelium: multiple layers of cells Pseudostratified epithelium: appears to be layered, but true layers do not exist because each cell touches the basement membrane TO PREVIOUS SLIDE

8. UNIT B Chapter 8: Human Organization Section 8.1 Figure 8.1 Epithelial tissue. Certain types of epithelial tissue—squamous, cuboidal, and columnar—are named for the shapes of their cells. They all have a protective function in addition to other specific functions. TO PREVIOUS SLIDE

9. UNIT B Chapter 8: Human Organization Section 8.1 TO PREVIOUS SLIDE

10. UNIT B Chapter 8: Human Organization Section 8.1 Epithelium as glands When an epithelium secretes a product, it is said to be glandular. A gland can be a single epithelial cell or can contain many cells. Glands that secrete their product into ducts are called exocrine glands (e.g., salivary glands) Glands that secrete their product into the bloodstream are called endocrine glands (e.g., thyroid gland) TO PREVIOUS SLIDE

11. UNIT B Chapter 8: Human Organization Section 8.1 Connective tissues have a wide variety of functions. Functions of connective tissue: Binds organs together Provides support and protection Fills spaces Produces blood cells Stores fat Connective Tissue TO PREVIOUS SLIDE

12. UNIT B Chapter 8: Human Organization Section 8.1 Structure of connective tissues: Connective tissue cells are widely separated by a solid, jellylike, or fluid matrix. A nonfluid matrix may contain three types of fibres: White collagen fibres: contain collagen to give flexibility and strength Reticular fibres: thin collagen fibres that form supporting networks Yellow elastic fibres: contain elastin to give elasticity TO PREVIOUS SLIDE

13. UNIT B Chapter 8: Human Organization Section 8.1 Blood is a liquid connective tissue. Functions of blood: Transports nutrients and oxygen to tissue fluid Removes carbon dioxide and other wastes Distributes heat Involved in fluid, ion, and pH balance Protects from disease Prevents fluid loss through clotting Blood TO PREVIOUS SLIDE

14. UNIT B Chapter 8: Human Organization Section 8.1 Composition of blood: Plasma: 55% inorganic and organic substances in water Formed elements: 45% Red blood cells, white blood cells, blood platelets Figure 8.2 Blood, a liquid connective tissue. a. Blood is often classified as connective tissue because the cells are separated by a matrix—plasma. The formed elements consist of several types of cells. TO PREVIOUS SLIDE

15. UNIT B Chapter 8: Human Organization Section 8.1 Figure 8.2 Blood, a liquid connective tissue. a. Blood is often classified as connective tissue because the cells are separated by a matrix—plasma. The formed elements consist of several types of cells. b. A drawing of the components of blood: plasma, red blood cells, white blood cells, and platelets (which are actually fragments of a larger cell). TO PREVIOUS SLIDE

16. UNIT B Chapter 8: Human Organization Section 8.1 TO PREVIOUS SLIDE

17. UNIT B Chapter 8: Human Organization Section 8.1 Formed elements of blood: Red blood cells (erythrocytes) Small, biconcave, disk-shaped cells without nuclei Contain the pigment hemoglobin, which makes the cells and blood red Hemoglobin associates with oxygen, allowing red blood cells to transport oxygen TO PREVIOUS SLIDE

18. UNIT B Chapter 8: Human Organization Section 8.1 White blood cells (leukocytes) Larger cells that have a nucleus Can fight infection through phagocytosis or through adaptive immunity Platelets (thrombocytes) Fragments of large cells present only in bone marrow Help form plugs to seal damaged blood vessels TO PREVIOUS SLIDE

19. UNIT B Chapter 8: Human Organization Section 8.1 Muscular tissue is composed of cells called muscle fibres, which function in voluntary and involuntary movement. There are three types of muscle tissue: Skeletal muscle Smooth muscle Cardiac muscle Muscular Tissue TO PREVIOUS SLIDE

20. UNIT B Chapter 8: Human Organization Section 8.1 Skeletal muscle Attached by tendons to the bones of the skeleton Has striated cells with multiple nuclei Functions in voluntary movement Figure 8.3 Muscular tissue. a. Skeletal muscle is voluntary and striated. TO PREVIOUS SLIDE

21. UNIT B Chapter 8: Human Organization Section 8.1 • Smooth muscle • Has spindle-shaped cells with a single nucleus • Cells do not have striations • Found in blood vessels and walls of viscera • Functions in movements that are involuntary Figure 8.3 Muscular tissue. b. Smooth muscle is involuntary and nonstriated. TO PREVIOUS SLIDE

22. UNIT B Chapter 8: Human Organization Section 8.1 • Cardiac muscle • Found only in walls of the heart • Has striated cells with a single nucleus in each cell • Involved in movements that are involuntary Figure 8.3 Muscular tissue. c. Cardiac muscle is involuntary and striated. Cardiac muscle cells branch and fit together at intercalated disks. TO PREVIOUS SLIDE

23. UNIT B Chapter 8: Human Organization Section 8.1 Nervous tissue, which contains nerve cells called neurons, is present in the brain and spinal cord. Functions of nervous tissue Sensory input: nerves conduct impulses from sensory receptors to the spinal cord and brain Integration of data Motor output: nerves conduct nerve impulses away from the spinal cord and brain to the muscles and glands Nervous Tissue TO PREVIOUS SLIDE

24. UNIT B Chapter 8: Human Organization Section 8.1 Structure of nervous tissue Nervous tissue contains neurons A neuron is a specialized cell that has three parts. Cell body: contains the nucleus and a majority of the cytoplasm Dendrites: conduct signals toward the cell body Axon: conducts nerve impulses away from the cell body; bundles of axons bound by connective tissue are called nerves Nervous Tissue TO PREVIOUS SLIDE

25. UNIT B Chapter 8: Human Organization Section 8.1 List five types of epithelium, and identify a location where each could be found in the human body. Describe the structure and function of skeletal, smooth, and cardiac muscle. Name the three parts of a neuron, and define nerve fibre. Check Your Progress TO PREVIOUS SLIDE

26. UNIT B Chapter 8: Human Organization Section 8.1 TO PREVIOUS SLIDE