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Circulation and Respiration Chapter 23 Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Outline • • • • • • Open vs. Closed Circulation Systems Vertebrate Circulatory System Functions Architecture of Vertebrate Circulatory System Fish Circulation Amphibian and Reptile Circulation Mammalian and Bird Circulation Heart Contraction Cardiovascular Diseases Respiration Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Open and Closed Circulatory Systems • • Cnidarians have cells directly exposed to external environment or to a body cavity (gastrovascular cavity) functioning in digestion and circulation. Larger animals transport oxygen and nutrients from the environment and digestive cavity to body cells by internal fluid within a circulatory system. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Open and Closed Circulatory Systems • • Open circulatory system - No distinction between circulating fluid and extracellular fluid of the body tissues (hemolymph). Closed circulatory system - Circulating fluid (blood) is always enclosed within vessels that transport blood away from, and back to, a pump (heart). Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Open and Closed Circulatory Systems • • • Arteries - Carry blood away from the heart. Veins - Return blood to heart. Capillaries - Pass blood between arterial and venous system. As blood plasma passes through capillaries, pressure forces fluid (interstitial fluid) out capillary walls. Returns to capillaries, and lymph vessels. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Animal Kingdom Circulatory Systems Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Vertebrate Circulatory System Functions • • Transportation Respiratory Nutritive Excretory Regulation Hormone Transport Temperature Regulation - Counter-current heat exchange Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Vertebrate Circulatory System Functions • Protection Blood Clotting Immune Defense Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Architecture of Vertebrate Circulatory System • • • Heart (Pump) Blood Vessels (Tube network) Blood (Circulating fluid) Leaves heart through arteries Passes into arterioles Forced through capillaries Passes to venules Flows to veins Back to heart Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Architecture of Vertebrate Circulatory System • Decrease in blood vessel size causes frictional resistance as fluid passes over walls. Heart must overcome high resistance in capillary network. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Architecture of Vertebrate Circulatory System • • Arteries Blood comes from heart in large pulses, thus artery must be able to expand. - Innermost layer composed of endothelial cells, surrounded by a thick layer of smooth muscle and elastic fibers. Arterioles Smaller in diameter than arteries, and surrounding muscle can be relaxed to enlarge diameter. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Architecture of Vertebrate Circulatory System • • Capillaries Transport oxygen and food from blood to body’s cells and pick up waste carbon dioxide. - Thin walls allow gas diffusion. Veins Return blood to heart Thin layers of muscles and elastic fibers Unidirectional valves Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Blood Vessel Structure Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Lymphatic System • Cardiovascular system is very leaky. Lymphatic system uses second circulatory system to gather liquid (lymph) . - Returns proteins to circulation. - Transports fats absorbed from intestine. - Aids in body’s defense. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Human Lymphatic System Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Blood • • Blood composed of plasma and several types of circulating cells. Plasma Components Metabolites and Wastes Salts and Ions Proteins Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Blood • Circulating Cells Erythrocytes (Red blood cells) Carry hemoglobin, and thus oxygen, to cells. Leukocytes (White blood cells) - Neutrophils - Macrophages - Lymphocytes B cells - produce antibodies T cells - attack invading bacteria Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Blood • Platelets Help blood to clot. - Large cells within bone marrow (megakaryocytes) pinch off bits of cytoplasm. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Fish Circulation • Fish heart is a four-chambered tube. First two, sinus venosus and atrium are collection chambers, while second two, ventricle and conus arteriosus are pumping chambers. Gill respiration delivers fully oxygenated blood to the body, but circulation is sluggish, limiting rate of oxygen delivery. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Heart and Circulation of a Fish Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Amphibian and Reptile Circulation • • Advent of lungs resulted in two circulations: Pulmonary circulation - (Lungs) Systematic circulation - (Rest of body) Amphibian heart has two two structural features to reduce mixing of oxygenated and deoxygenated blood. Atrium divided into two chambers. Conus arteriosus partially separated by septum. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Amphibian Heart and Reptile Circulation Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Mammalian and Bird Circulation • Mammals, birds, and crocodiles have fourchambered heart made up of two pumping systems. Oxygenated blood from lungs empties into left atrium through pulmonary veins. - From atrium, flows into left ventricle. Ventricle contracts and forces blood out in a single strong pulse. Mitral valve prevents back-flow. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Mammalian and Bird Circulation • • Blood within contracting left ventricle moves into aorta. Separated from left ventricle by one - way aortic valve. Blood eventually returns to heart. Superior Vena Cava drains upper body. Inferior Vena Cava drains lower body. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Mammalian and Bird Circulation • Right Side Blood passes from right atrium into right ventricle through one-way tricuspid valve. Passes out contracting ventricle through pulmonary valve into pulmonary arteries. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Heart Contraction • Heartbeat originates in sinoatrial (SA) node. Membranes spontaneously depolarize. - Depolarization passes to ventricles through atrioventricular (AV) node. Bundle of His Purkinje Fibers Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Monitoring Heart’s Performance • • • Listen to heart at work If valves are not fully opening or closing, turbulence is created and can be heard as a heart murmur. Measure Blood Pressure Diastolic (Low point) Systolic (High point) Measure Depolarization Magnitude of electrical pulse. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Cardiovascular Diseases • • • Heart Attacks Blood clot in coronary arteries. - Angina pectoris Strokes Interference with blood flow to brain. Atherosclerosis Accumulation of fatty acids, smooth muscle, cholesterol and cellular debris. - Arteriosclerosis - Calcium deposits. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Respiratory Systems • Respiration - Uptake of oxygen and simultaneous release of carbon dioxide. Gills (Aquatic organisms) Trachea (Terrestrial arthropods) - Spiracles Lungs (Terrestrial vertebrates) Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Respiration in Aquatic Vertebrates • A fish swimming continuously pushes water through mouth and out gills. Permits countercurrent flow. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Respiration in Terrestrial Vertebrates • • Amphibians obtain oxygen via lungs and can respire through moist skin. Reptiles need more oxygen, but cannot rely on skin. Lungs contain many small air chambers increasing surface area. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Respiration in Terrestrial Vertebrates • Mammals have large metabolic oxygen demands due to maintenance of body temperature. Alveoli - Small chambers in lung interior. Bronchiole - Passageways connecting clusters of aveoli. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Evolution of Vertebrate Lung Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Respiration in Terrestrial Vertebrates • Bird Lungs Flying creates a large oxygen demand, thus birds possess high lung efficiency. - Air flows into the lungs in one direction. No dead volume - full oxygenation. - Blood runs in different direction. Blood leaving lung can still contain more oxygen than exhaled air. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Bird Respiration Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Mammalian Respiratory System • Pair of lungs hang free within thoracic cavity. Bronchus connects each lung to trachea. - Air enters through nostrils (or mouth), passes into larynx, and then into trachea. Passes down bronchus to lungs. Thoracic cavity bounded by diaphragm. Each lung covered with pleural membrane. Weight of lung supported in thoracic cavity by interpleural fluid. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Human Respiratory System Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Mechanics of Breathing • • During inhalation, muscular contraction causes walls of chest cavity to expand, so that rib cage moves outward and upward. Diaphragm flattens Internal air pressure decreases During exhalation, ribs and diaphragm return to original resting position, forcing air from inner cavity back to atmosphere. Typical tidal volume (0.5) liters of air. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Mechanics of Breathing • • Typical human breath at rest, tidal volume, moves about (0.5) liters of air. Lung still contains residual volume of air after breath completed (1200 milliliters). Each exhalation removes approximately same volume as inhalation added. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Gas Exchange • • Oxygen moves within circulatory system carried piggyback on hemoglobin. Hemoglobin uptakes oxygen within red blood cells, and causes diffusion from blood plasma. Carbon dioxide in tissue speeds up unloading of oxygen. - Bohr Effect Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Gas Exchange • • As red blood cells are unloading oxygen, they are also absorbing carbon dioxide from the tissue. To keep carbon dioxide from diffusing out of red blood cells back into plasma, carbonic anhydrase combines with carbon dioxide and water to form carbonic acid. Hemoglobin also has ability to hold and release nitric oxide. Regulates blood pressure and blood flow. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Nature of Lung Cancer • • One of leading causes of death among adults in the world. Most carcinogens are also mutagens. Tumor Suppressor Genes Rb protein - acts as brake on cell division. P53 protein - inspects DAN prior to division. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Smoking Causes Lung Cancer • Cigarette smoke contains many mutagens: Benzo[a]pyrene binds to three sites on p53 and causes mutations at the inactivation sites. - Research found p53 gene inactivated in 70% of all lung cancers. - Nicotine is an addictive drug. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Review • • • • • • Open vs. Closed Circulation Systems Vertebrate Circulatory System Functions Architecture of Vertebrate Circulatory System Fish Circulation Amphibian and Reptile Circulation Mammalian and Bird Circulation Heart Contraction Cardiovascular Diseases Respiration Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies