copyright 2010 pearson education, inc. chapter 16 tissues, organs, and organ systems organ donation

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Copyright © 2010 Pearson Education, Inc Tissues - Epithelial Tissue Epithelium is tightly packed sheets of cells  cover organs and outer surfaces  line insides of hollow organs, vessels, and body cavities. Figure 16.1 (a) Examples of organs lined with epithelial tissue: (b) Epithelial cells in skin Heart and blood vessels Respiratory tract Digestive tract Urogenital tract Epidermis (c) Epithelial cells lining the small intestine

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Copyright 2010 Pearson Education, Inc. Chapter 16 Tissues, Organs, and Organ Systems Organ Donation Copyright 2010 Pearson Education, Inc Tissues Tissues = group of similar cell types that perform a common function. Four basic types of tissue: 1.Epithelial 2.Connective 3.Muscle 4.Nervous Copyright 2010 Pearson Education, Inc Tissues - Epithelial Tissue Epithelium is tightly packed sheets of cells cover organs and outer surfaces line insides of hollow organs, vessels, and body cavities. Figure 16.1 (a) Examples of organs lined with epithelial tissue: (b) Epithelial cells in skin Heart and blood vessels Respiratory tract Digestive tract Urogenital tract Epidermis (c) Epithelial cells lining the small intestine Copyright 2010 Pearson Education, Inc Tissues - Epithelial Tissue Epithelia are polar anchored on one surface, but free on another The free side is typically exposed to the environment or body fluids Can be single layer or many layers thick Function in protection, secretion, and absorption Epithelial cells are continuously sloughing off and are replaced by cell division Copyright 2010 Pearson Education, Inc Tissues - Connective Tissue Connective Tissue Loosely organized and composed of cells embedded in a matrix Cells Blood cells, adipocytes, fibroblasts, chondrocytes, osteocytes Matrix is composed of two things 1.Ground substance Liquid, gel-like, rubbery or solid 2.Fibers Collagen, elastin, reticular fibers Copyright 2010 Pearson Education, Inc Tissues - Connective Tissue Connective Tissue Usually binds organs or tissues to one another Six different types: Loose connective tissue Adipose tissue Blood Fibrous connective tissue Cartilage Bone Copyright 2010 Pearson Education, Inc. Figure 16.2a 16.1 Tissues - Connective Tissue Most widespread tissue in animal body Matrix composed of collagen and elastin fibers It is called loose because fibers are loosely woven together Binds epithelia to tissues, pads skin, and holds organs in place Loose Connective Tissue Copyright 2010 Pearson Education, Inc Tissues - Connective Tissue Adipose Tissue AKA Fat Primarily adipose cells; small amount of matrix Functions Used for storage of energy (fat) Insulation Padding for organs Figure 16.2b Copyright 2010 Pearson Education, Inc Tissues - Connective Tissue Blood Cellular component red blood cells, white blood cells and platelets Matrix is the plasma Functions include carrying oxygen and nutrients; fighting infection Figure 16.2c Red blood cell Platelet White blood cell Plasma (c) Blood Copyright 2010 Pearson Education, Inc Tissues - Connective Tissue Fibrous Connective Tissue Forms tendons and ligaments Matrix is collagen fibers running in parallel Figure 16.2d Fibroblast cell Parallel collagen fibers (d) Fibrous connective tissue (tendon) Copyright 2010 Pearson Education, Inc. Figure 16.2e Matrix Chondro- cytes (e) Cartilage (at the end of a bone) 16.1 Tissues - Connective Tissue Cartilage Chondrocytes Secrete rubbery matrix, collagen and elastin Cartilage cushions joints, forms support for ears and nose Not vascularized, so takes a long time to heal if injured Copyright 2010 Pearson Education, Inc. Figure 16.2f Matrix Osteocytes Central canal (f) Bone 16.1 Tissues - Connective Tissue Bone Rigid connective tissue Osteocytes secrete matrix of collagen fibers and calcium salts Bone marrow produces blood cells Body can make use of calcium from bones if dietary levels are too low Copyright 2010 Pearson Education, Inc Tissues - Muscle Tissue Muscle is contractile tissue Long, thin cylindrical cells called muscle fibers Two proteins actin and myosin interact to cause contraction of muscle fibers Three types of muscle: 1.Skeletal 2.Cardiac 3.Smooth Copyright 2010 Pearson Education, Inc Tissues - Muscle Tissue Skeletal Muscle Usually attached to bone Produces all voluntary movements Striated Long, thin, cylindrical shape Figure 16.3a Muscle fiberNucleus (a) Skeletal muscle (biceps) Copyright 2010 Pearson Education, Inc. Figure 16.3b (b) Cardiac muscle (heart) Muscle fiber Nucleus 16.1 Tissues - Muscle Tissue Cardiac Muscle Only found in heart tissue Striated involuntary, undergoes rhythmic contractions to produce heartbeat Branched, interlocking cells propagate signal to contract almost simultaneously Copyright 2010 Pearson Education, Inc. Figure 16.3c Muscle fiber Nucleus (c) Smooth muscle (intestine) 16.1 Tissues - Muscle Tissue Smooth Muscle Not striated Spindle-shaped cells Musculature of organs, blood vessels, digestive tract Involuntary Contracts more slowly and for longer than skeletal muscle Copyright 2010 Pearson Education, Inc Tissues - Nervous Tissue Nervous Tissue Neurons conduct electrical signals Primary cells of the brain and spinal cord Main function of neurons is to: Sense stimuli Process stimuli Transmit signals Most cells of nervous system do not undergo cell division Copyright 2010 Pearson Education, Inc Tissues - Tissue Donation Brain death and Tissue Donation Injuries from motor vehicle accidents, burst blood vessels, and drowning are common causes of brain death Once dead, brain cells cannot recover Tissues can be harvested to help others > One persons tissues can improve the lives of as many as 50 people. Copyright 2010 Pearson Education, Inc. Figure Organs and Organ Systems Organs are composed of two or more tissue types Organs that act together form an organ system All the organ systems of a body form an organism Muscle cell Muscle tissue Heart organ Circulatory system Organism Copyright 2010 Pearson Education, Inc Organs and Organ Systems Figure Organ Systems Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Liver as a Model Organ The liver sits below the diaphragm comprised of four lobes associated with the gall bladder. Figure 16.6 Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Liver as a Model Organ The liver is an important component of the digestive and the circulatory system As part of the circulatory system, the liver: Synthesizes blood clotting factors Detoxifies Regulates blood volume Destroys old red blood cells As part of the digestive system, the liver: Produces bile Metabolizes and stores nutrients Copyright 2010 Pearson Education, Inc Organs and Organ Systems Liver Structure Epithelia Hepatocytes Lining blood vessels Lining bile ducts Connective Tissue Loose connective tissue Kupffer cells Copyright 2010 Pearson Education, Inc Organs and Organ Systems - The Liver as a Model Organ Liver transplants can be made from living donors or from brain dead ones Unlike many organs, liver can regenerate itself Portion can be taken from living donor and implanted in patient Liver in donor and patient will regrow to normal size Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Digestive System Figure 16.8 Mouth Teeth reduce the size of food, increasing surface area available for digestion by enzymes. Amylase enzymes in saliva start breaking down carbohydrates. Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Digestive System Figure 16.8 Esophagus The esophagus transports food to stomach by rhythmic waves of muscle contractions called peristalsis. Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Digestive System Figure 16.8 Stomach HCl starts breaking down foods. The enzyme pepsin breaks down proteins. Mucous prevents gastric juices from digesting stomach. Pyloric sphincter regulates movement of food from stomach to small intestine. Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Digestive System Figure 16.8 Small intestine Most digestion of carbohydrates, proteins, and fats occurs here. Nutrients are absorbed into the bloodstream. Large intestine Water is reabsorbed Copyright 2010 Pearson Education, Inc Organs and Organ Systems - The Digestive System Villi and microvilli increase the surface area of the intestines to allow nutrient absorption Figure 16.9 Villus Lumen Mucosal folds Small intestine One villusMicrograph Blood capillaries Arteriole Venule Lymphatic vessel Microvilli Nutrients in small intestine Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Digestive System Figure 16.8 Accessory Organs Liver Produces bile which aids absorption of fats Gall bladder Stores bile and empties into small intestine Copyright 2010 Pearson Education, Inc Organs and Organ Systems The Digestive System Figure 16.8 Accessory Organs Pancreas Produces LOTS of digestive enzymes Produces a buffer that neutralizes stomach acid Enzymes & buffer are released into small intestine Copyright 2010 Pearson Education, Inc Organs and Organ Systems An organ system consists of many organs working together Failure of one organ may compromise the entire system Intestine transplants and pancreatic transplants are becoming more common Gall bladder and stomach transplants are rarely done Organ failure can also disrupt multiple systems Copyright 2010 Pearson Education, Inc Organs and Organ Systems AnimationThe Digestive System PLAY Copyright 2010 Pearson Education, Inc Organs and Organ Systems Evolution of the Digestive System Paramecia use digestive food vacuoles Hydra have an extracellular digestive sac Earthworms have alimentary canal Allows for assembly line like specialization Figure 16.9 Copyright 2010 Pearson Education, Inc. Homeostasis a dynamic state of equilibrium in which internal conditions remain relative stable (Steady State) homeostasis regulates conditions in the internal environment A homeostatic control system has a receptor a control center a set point an effector James M. Hutcheon Georgia Southern University PowerPoint lecture prepared by Copyright 2010 Pearson Education, Inc. LE Response No heat produced Room temperature decreases Room temperature increases Set point Too hot Set point Heater turned off Too cold Set point Control cen