Transcript chapt 24
Chapter 24 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. 24-1 Exchanging Materials: Basic Principles Large, multicellular organisms need a way to deliver oxygen and nutrients to the cells deep within tissues. Several organ systems help deliver oxygen, nutrients to and remove wastes from cells. – 24-2 Circulatory, lymphatic, respiratory, digestive, and excretory systems Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Cardiovascular System Pumps blood around the body Consists of – Blood – The heart – A muscular pump that forces fluid through the body Vessels 24-3 Fluid tissue that transports materials and heat “Pipes” that move blood through the body Arteries carry blood from the heart to the tissues. Capillaries are small vessels that carry blood through tissues. Veins carry blood from the tissues to the heart. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Nature of Blood Consists of – Several types of cells – Plasma 24-4 Called the formed elements Contains different kinds of dissolved molecules Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Formed Elements Red blood cells – – – – – 24-5 Lack a nucleus Contain hemoglobin Transport oxygen and carbon dioxide Carbonic anhydrase converts carbon dioxide to bicarbonate that can be dissolved in the blood. Anemia is a lack of oxygen resulting from a lack of red blood cells. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Formed Elements White blood cells – – – – – 24-6 Also called leukocytes Lack hemoglobin Have a nucleus Include basophils, eosinophils, neutrophils, lymphocytes, and monocytes Defend the body against microorganisms, damaging chemicals, and cancer Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Formed Elements Platelets – – – Not whole cells Fragments of white blood cells Important in blood clotting 24-7 Collect at the site of a wound Release clotting factors – Initiate a sequence of reactions that trap blood cells to form a clot – Eventually the clots (scabs) are replaced by healthy, living tissue. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Plasma Liquid part of the blood Contains – Salts that serve to 24-8 Buffer and maintain blood pH Maintain osmotic balance – Keeps the tissue fluid between cells at the right solute concentration so that it flows into the capillaries, maintaining blood pressure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Plasma Proteins – – Nutrients – – – 24-9 Antibodies and other immune proteins Albumin to maintain osmotic balance Transports bilirubin from degraded RBCs to the liver Accumulated bilirubin can cause jaundice Amino acids Sugars Lipoproteins carry fats and cholesterol Hormones Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Composition of Blood 24-10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Functions of Blood Transports molecules, cells – – – – – Regulates temperature – – 24-11 Oxygen, carbon dioxide Nutrients Waste products Immune cells and antibodies Hormones If body temperature is too high, blood will be shunted to the body surface to radiate heat. If body temperature is too low, blood will be shunted to the body core to conserve heat. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Heart 24-12 Pumps the blood Generates the pressure necessary to move blood through vessels – Blood must flow to move nutrients to tissues and waste away from tissues. – Heart must repeatedly contract in order to keep blood moving. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mammalian Heart Has four chambers with four valves – Two atria and two ventricles Ventricles – – – Are larger and more muscular Force blood through the arteries to the body The aorta and pulmonary artery flow out of the ventricles. Atria – – 24-13 Are smaller with thinner walls Pump blood into the ventricles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mammalian Heart Atria and ventricles are separated by atrioventricular valves. – Semilunar valves in the aorta and pulmonary arteries – Act as “check valves” to prevent blood from flowing back into the ventricles when they relax Damaged valves causes inefficient pumping. – 24-14 Valves ensure that the blood only flows in one direction. Detected as heart murmurs because some of the blood is being pushed backward Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Anatomy of the Heart 24-15 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mammalian Heart Two different sides have different jobs – – The right atrium receives blood from the body. The right ventricle pumps the blood to the lungs. – – The left atrium receives blood from the lungs. The left ventricle pumps blood to all other parts of the body. 24-16 Called pulmonary circulation Allows for the exchange of carbon dioxide and oxygen in the lungs Called systemic circulation Allows for the delivery of oxygen, nutrient, and waste exchange in the tissues Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pulmonary and Systemic Circulation 24-17 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood Vessels The tubes that transport blood from one place to another in the body Types of blood vessels – – – 24-18 Arteries Veins Capillaries Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Arteries Carry blood away from the heart Contraction of the ventricles increases the pressure in the arteries. – Relaxation of the ventricles decreases the pressure in the arteries. – 24-19 Called systolic blood pressure Called diastolic blood pressure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Arteries Blood pressure readings include both types of blood pressure. – – Have thick, muscular, and elastic walls – 24-20 Systolic/diastolic 120/80 Can stretch when pressure increases Branch into arterioles to take blood throughout the body Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Veins 24-21 Collect blood from the capillaries and return it to the heart Have very low pressure Walls not very muscular Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Veins Have valves to prevent backflow – Contraction of leg muscles aids in pushing blood through veins. – 24-22 Dysfunctional valves cause varicose veins. Sitting or standing for a long time can cause pooling of blood in the feet. Causes swelling Can cause fainting because the brain doesn’t get enough blood Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Structure of Arteries, Veins, and Capillaries 24-23 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Capillaries Tiny vessels, one-cell thick – Have thin walls – – – 24-24 Only one-cell thick Allows materials to diffuse into and out of the blood Allows liquid to be exchanged between the blood and tissue fluid Are numerous – RBC go through capillaries single file All cells in the body have a capillary nearby. Flow of blood through capillaries is slow – Allows time for diffusion and fluid exchange Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Capillaries 24-25 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Lymphatic System A second circulatory system A collection of thin-walled vessels – – Functions – – – 24-26 Called lymph vessels Branch throughout body and lymph organs Moves fat from digestive system to blood stream Transports excess fluid back to cardiovascular system Carries immune cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Lymphatic System 24-27 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Lymphatic System Lymph – – – Edema – 24-28 Fluid tissue that is moved through the lymph organs via lymph vessels Emptied into large veins near the heart Moved through lymph vessels by muscle contraction Accumulation of fluid in tissues Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lymph Organs Lymph nodes – – – – Tonsils – – – 24-29 Filter lymph Contain large numbers of white blood cells Remove microorganisms and foreign particles from the lymph When an infection is active, the lymph nodes enlarge Near the throat Contain the tonsils and the adenoids Filter pathogens that enter through the mouth and nose Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lymph Organs Spleen – – Contains a large number of white blood cells Filters the blood – Located just below the diaphragm Thymus – – – 24-30 Cleans out pathogens and dying RBCs Produces WBCs called T-lymphocytes Most active in children Shrinks as one ages Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lymph Organs Red bone marrow – – – 24-31 Found in children’s bones Reduced in adult bones Produces RBCs, WBCs, and platelets Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Respiratory System Moves air into and out of the body Lungs – Trachea – – – – A tube that carries air into and out of the lung Branches into bronchi then into bronchioles Bronchioles end in alveoli Alveoli are small sacs where gas exchange takes place Air-transport pathway – – 24-32 Allow gas exchange between air and blood Includes the nose, mouth, and throat Pulls air into the trachea Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Respiratory Anatomy 24-33 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Breathing System Regulation Breathing is the process of moving air into and out of the lungs. Involves the diaphragm – – – 24-34 A large muscle that separates the chest cavity (containing lungs) from the abdominal cavity When contracted, the diaphragm moves down Creates negative pressure in the chest cavity Pulls air into the lungs When relaxed, the diaphragm resumes its normal position Generates positive pressure in the chest cavity Pushes air out of the lungs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Breathing Movements 24-35 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Breathing During Exercise Exercise increases the body’s demand for oxygen. – – 24-36 Requires faster gas exchange in lungs Accomplished by Increased breathing rate – Can involve greater diaphragm contraction to pull in more air Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Breathing During Exercise Can also involve contraction of abdominal muscles to fully empty the lungs – This happens when carbon dioxide concentration increases in the blood and blood pH. – 24-37 Sensed by brain, then brain causes increased contraction of the diaphragm and intercostal muscles Increased air exchange volume in each breath Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Control of Breathing Rate 24-38 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lung Function Lungs are specialized so that blood and air can come very close together. – – – – 24-39 This facilitates gas exchange between them. Blood flows through capillaries in the lungs that come very close to the air in the alveoli. Oxygen and carbon dioxide cross the alveoli and capillary walls. Therefore, the surface area of the alveoli must be very large (collectively). This is why there are so many alveoli. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Association of Capillaries with Alveoli 24-40 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lung Function Gas exchange is facilitated by blood and air movement. – – – 24-41 Blood enters the lungs high in carbon dioxide and low in oxygen. Air enters the lungs high in oxygen and low in carbon dioxide. Therefore, carbon dioxide diffuses from the blood to the air and oxygen diffuses from the air to the blood. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Disrupting Lung Function Interfering with blood flow or gas exchange will reduce the efficiency of the organism. – – – 24-42 A poorly pumping heart reduces the amount of blood that is sent to the lungs. Constriction of bronchioles (asthma) reduces the amount of air that can enter the alveoli. Reducing the number of alveoli (emphysema) reduces the surface area for gas exchange. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Digestive System Responsible for processing and distributing nutrients – – – – Consists of – – 24-43 Mechanical processing Chemical processing Nutrient uptake Chemical alteration A muscular tube Glands that secrete digestive juices Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Digestive System 24-44 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mechanical and Chemical Processing The process of taking large pieces of food and breaking them down into individual molecules that can be absorbed Mechanical processing – 24-45 Chewing in the oral cavity generates a food bolus. Increases surface area of food Allows digestive enzymes greater access to the food Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mechanical and Chemical Processing Salivary glands produce saliva containing some digestive enzymes. – Chewing mixes the food with the saliva. – Tongue 24-46 Salivary amylase begins to break down starch. Tastes food Pushes food back toward throat Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mechanical and Chemical Processing Food bolus passes through the esophagus to the stomach – – Moves from mouth to the pharynx into the esophagus Contractions of the pharynx move the food toward the stomach. In the stomach, food is churned. – Mixes food with digestive juices – – 24-47 Pepsin breaks down proteins. Low pH denatures proteins The food then moves to the small intestine where chemical breakdown is completed. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mechanical and Chemical Processing Chemical processing in the small intestine – – Also known as the duodenum Receives digestive enzymes and bicarbonate ions from the pancreas – Receives bile from the liver by way of the gall bladder 24-48 Digestive enzymes complete the chemical processing of food. Bicarbonate neutralizes the low pH of the food coming from the stomach. Emulsifies fat into smaller fat globules Allows digestive enzymes greater access to the fats Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mechanical and Chemical Processing Finally, the remainder of the undigested food passes from the small intestine to the large intestine (colon). – – – 1.5 meters long Water is reabsorbed. Contains bacteria that utilize the undigested food 24-49 These bacteria produce vitamins that we need. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Digestive Enzymes 24-50 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nutrient Uptake Once food is broken down into individual macromolecules, they can be absorbed into the bloodstream. – – 24-51 Absorption occurs through the lining of the small intestine. Requires a large surface area The small intestine is very long (6 to 8 meters). The lining of the small intestine has fingerlike projections called villi. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nutrient Uptake Each villus contains – – Involves diffusion – – – 24-52 Several capillaries A lymphatic vessel called a lacteal Water and small ions move into blood via simple diffusion. Sugars and amino acids move into blood via carrier proteins. Fatty acids and glycerol enter intestinal cells where they are built into fats and transported into the lacteals. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chemical Alterations: The Role of the Liver The nutrient-rich blood leaves the intestine and goes straight to the liver. – In the liver – – 24-53 Moves through the hepatic portal vein Enzymes modify the nutrient molecules. Foreign organisms are filtered out. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chemical Alterations: The Role of the Liver Toxic substances are detoxified – – Excess glucose is collected and stored as glycogen. Excess amino acids are converted to – – – 24-54 Ethyl alcohol Plant toxins Other types of amino acids Glucose and stored Urea and sent to the kidneys Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Excretory System (The Urinary System) Responsible for the processing and elimination of metabolic waste – – – – – 24-55 Urea Toxic substances Hydrogen ions Water Salts Consists of – – – – Kidneys Ureters Urinary bladder Urethra Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Urinary System 24-56 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Structure 24-57 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Function In order to filter out waste, kidney must have a close association with bloodstream – – Exchange of waste occurs across a surface Requires large surface area 24-58 Glomerulus represents a large surface area Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Function Major activities in kidney – Filtration Blood enters glomerulus under pressure as the heart contracts. Glomerular capillaries are porous. – 24-59 Glucose, amino acids, ions, and water are pushed through the pores into the nephron tubules. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Function Reabsorption – – Not everything that is filtered into the nephron needs to be excreted. Some molecules are reabsorbed into capillaries around the nephron. – – Occurs mostly in the proximal convoluted tubule Water is reabsorbed in the Loop of Henle. 24-60 Amino acids, glucose, sodium Occurs because of osmotic gradients that exist in the kidney Concentrates the urine and conserves water Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Function Secretion – 24-61 Additional waste is moved from the capillaries around the nephron into the distal convoluted tubule. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Specific Functions of the Nephron 24-62 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.