Bio3 Chapter 19 Study Guide 1. Define homeostasis. 2. What is the function of feedback systems? 3. Distinguish between a negative feedback system and a positive feedback system. 4. Know and understand examples of negative feedback: the non-living thermostat/heater and the biological thermostat in the human body. 5. Distinguish between cells, tissues, organs and organ systems. 6. What are the 4 main groups of animal tissues? Epithelial, connective tissue, muscle tissue, and nervous tissue 7. Which tissue forms the outer membrane that covers the body and lines the body’s cavities and is underlain by a layer of basal lamina; is a tissue that forms glands and therefore functions in secretion; is a tissue that functions in diffusion, absorption, excretion/filtration, surface transport and sensory detection? Epithelial tissue 8. Know: a. The three shapes of epithelial cells & distinguish between them. b. What is the difference between simple, stratified, and pseudostratified epithelial tissue? 9. What kind of simple epithelial tissue lines the sacs of the lungs (alveoli), lines blood vessels (endothelium), and lines the chambers of the heart? Simple squamous epithelial tissue 10.What is the function of the thin and flattened layer of simple squamous epithelial tissue in: a. Alveoli? Rapid diffusion of oxygen from the lungs into blood capillaries b. Capillaries? Rapid diffusion of gases in pulmonary capillaries, and diffusion of gases, nutrients and wastes with extracellular fluid in tissue beds. c. Arteries and veins? The smooth, tight interlocking of cells provides a smooth surface for blood flow within blood vessels (with little friction or drag). 11.Where do you find the epidermis and what type of tissue is this? a. It is the outer layer of the skin b. it is composed of stratified squamous epithelial tissue that is keratinized (keratin is a strong elastic protein that makes waterproof and airtight) c. It consists of 4-5 cell layers, with the outer cell layer being flat dead cells that will be lost and the deepest basal layer cells being capable of continual mitosis to replace the outer cells that have been lost; it is avascular. 12. Know this about simple columnar epithelial tissue: a. It may contain scattered goblet cells that secrete mucus (or lubricating substance); mucus can trap dust/carcinogens as in respiratory tract. b. It may have cilia and function in surface transport: cilia are (fine hair –like projections on free surfaces) that are capable of rapid, rhythmic, wavelike beatings in a certain direction; for example, cilia can cause mucus (secreted by the goblet cells) to move (flow or stream) in that direction. c. It may have microvilli (finger-like projections) at apical surface that increase the tissue surface area to maximize absorption 13.Where do you find simple columnar epithelial tissue? a. Lines the stomach: secretes mucus to protect the lining from self-digestion (high acidity). b. Lines the intestines: cells have microvilli to increase absorption of nutrients into the blood c. Lines the uterine tubes: cells have cilia whose beating create a current for sperm moving up the fallopian tubes 14.Where can you find pseudo-stratified ciliated columnar epithelial tissue with mucus secreting goblet cells? a. First it is a single layer of columnar epithelial tissue that falsely appears as more than one layer (thus pseudo-stratified) b. You can find this tissue in the respiratory tract: lining of the trachea, of the bronchi, and the nasal cavities. 15.Exocrine glands and endocrine glands are formed from epithelial tissue. What is the difference between exocrine glands and endocrine glands? 16.What is connective tissue and its functions? a. Tissue composed of widely scattered fibroblast cells lying within an extracellular matrix of ground tissue and flexible protein fibers (secreted by the fibroblasts). b. Some fibers include: soft and flexible collagen (most abundant) and elastic elastin (can be stretched and snaps back) c. It is typically covered by epithelial tissue d. General Functions: to support and bind other tissues; and to separate more specialized tissues and organs of the body. 17.What are 3 types of connective tissue (CT)? a. Loose (areolar/dermis) b. Fibrous (Tendons & ligaments) c. Specialized (cartilage, bone, adipose tissue, blood and lymph)- specialized functions. 18.Describe loose CT. Loose connective tissue has several kinds of scattered cells and interlacing bundles of fibers in a jelly-like matrix (the major fiber is collagen); it is vascular. 19.Where is loose (areolar) CT found in the skin and what does it provide to the overlaying tissue? Loose CT is found in the dermis layer (under the epidermis) of the skin. The dermis contains blood vessels, nerves, hair roots and sweat glands. The dermis blood supply provides nutrients and a ready supply of infection fighting leukocytes to the epidermis – must reach through diffusion. 20.What is found in the hypdermis (below the dermis) adipose tissue, connective tissue and arterioles and venules 21.Describe dense fibrous CT and where is it found? Fibroblast cells within a matrix of densely packed fibers in an orderly and parallel arrangement. It forms: a. Tendons which are strong connections between muscles and bones (mainly collagen fibers b. Ligaments that connect bone to bone at joints (mainly collagen fibers). c. Ligaments that hold bones of the backbone 22.What is cartilage? A flexible and resilient CT with widely spaced chondrocytes (cells) in lacunae (liquid lakes) with a matrix of collagen and elastin fibers; and has no blood supply-so cells are fed by diffusion, so if damaged it is slow to heal. 23.Where do you find cartilage? a. Hyaline cartilage: ends of bones at joints (knees) and rings of trachea b. Fibrocartilage: shock-absorbing pads between the vertebrae (spinal disks) c. Hyaline cartilage: Tips of nose and in ear lobe 24.How is matrix of bone (osseous tissue) different from that of cartilage? The matrix of bone is hardened by deposits of calcium and forms in concentric circles around a central canal. 25.What is the structure and function of adipose tissue? Adipose tissue is a loose CT specialized for fat storage (a droplet of fat occupies must of the space within a cell, pushing the nuclei to one end). It functions as a long-term energy reserve, it provides protection, and serves as an insulator (reduces heat loss through the skin). 26.Describe blood and function of its cellular components. It is a specialized CT in which red blood cell, white blood cells and platelets are suspended within a liquid matrix called plasma. Red blood cells or erythrocytes bind and transport oxygen; white bloods cells or leukocytes fight infection; Platelets are cell fragments that aid in blood clotting. 27. What is muscle tissue? Specialized contractile tissue. 28.What is the basic structure of muscle tissue? Muscle cells (muscle fibers) are abundant in contractile protein fibers (whose most basic components are the myofilaments actin and myosin). The actin and myosin filaments slide past each other allowing the muscle cells to shorten (contract) and relax (lengthen), generating the force of contraction. 29.What are the 3 types of muscle tissue? Skeletal, cardiac, and smooth. 30.Which of these muscle tissues is/are striated? Skeletal and cardiac. 31. Which of these muscle tissues is/are under voluntary control and allows for the movement of the bones of the skeleton? Skeletal muscle. 32.Describe the structure of skeletal muscle cells (fibers). Very long, multinucleated cells that run length of the muscle fiber. Each cell is packed with long protein fibers (myofilaments) of actin and myosin. There are thousands of myofilaments in a myofibril, many myofibrils in a muscle fiber (muscle cell) and many muscle fibers (muscle cells) in a muscle. 33.Describe/draw the structure of a myofibril and sarcomere (thin filament, thick filament, and Z-line) in skeletal muscle. 34.Describe how skeletal muscle contracts. 35.What is a motor end plate in skeletal muscle? 36.Where do you find cardiac muscle and what is its function? In the walls of the heart; involuntary contraction of heart. 37.Where do you find smooth muscle and what is its function? In the walls of the stomach and intestine, large blood vessels, bladder and uterus and powers involuntary contractions commanded by the central nervous system. 38.The last tissue is the nervous tissue. What two general types of cells are in the nervous tissue and their functions? Neurons – transmit electrical signals; Glial cells – surround, support, electrically insulate and protect neurons. 39.Know the general structure of neuron.