Chapter 24 Circulation and Respiration Lecture Outline PDF

Because learning changes everything. ® Chapter 24 Circulation and Respiration Lecture Outline Essentials of the Living World Seventh Edition George Johnson, Joel Bergh © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hi...

Because learning changes everything. ® Chapter 24 Circulation and Respiration Lecture Outline Essentials of the Living World Seventh Edition George Johnson, Joel Bergh © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  24.1 Open and Closed Circulatory Systems 1 Among the unicellular protists, oxygen and nutrients are obtained directly by simple diffusion. Cnidarians and flatworms have cells that are directly exposed to either the external environment or to a gastrovascular cavity. © McGraw Hill, LLC 2  24.1 Open and Closed Circulatory Systems 2 Large animals have tissues that are several cell layers thick so that many cells are too far away for surface exchange. Instead, oxygen and nutrients are transported from the environment and digestive cavity to the body cells by an internal fluid within a circulatory system. There are two main types of circulatory systems. Open circulatory system. Closed circulatory system. © McGraw Hill, LLC 3  24.1 Open and Closed Circulatory Systems 3 In open circulatory systems, there is no distinction between the circulating fluid (blood) and the extracellular fluid of the body tissues. This fluid is called hemolymph. Insects have a muscular tube that serves as a heart to pump the hemolymph through a network of open-ended channels. © McGraw Hill, LLC 4  24.1 Open and Closed Circulatory Systems 4 In a closed circulatory system, the circulating fluid (blood) is always enclosed within blood vessels that transport blood away from and back to a heart. Annelids, like earthworms, and all vertebrates have a closed circulatory system. Arteries carry blood away from the heart. Exchange of gases and nutrients occurs through thin-walled tiny capillaries. Veins return blood to the heart. © McGraw Hill, LLC 5  Figure 24.1: Three types of circulatory systems found in the animal kingdom Access the text alternative for slide images. © McGraw Hill, LLC 6  24.1 Open and Closed Circulatory Systems 5 The circulatory system has three primary functions: Transportation. Gases, nutrients, wastes, and hormones are transported by the circulatory system. Regulation. The cardiovascular system regulates body temperature. Vertebrates retain heat in a cold environment using countercurrent heat exchange. Protection. The circulatory system protects against injury and foreign microbes or toxins introduced into the body. © McGraw Hill, LLC 7  Figure 24.2: Countercurrent heat exchange Access the text alternative for slide images. © McGraw Hill, LLC 8  24.2 Architecture of the Vertebrate Circulatory System 1 The vertebrate circulatory system (also known as the cardiovascular system) is made up of three elements. Heart—a muscular pump that pushes blood through the body. Blood vessels—a network of tubes through which the blood moves. Blood—fluid that circulates through the vessels. © McGraw Hill, LLC 9  24.2 Architecture of the Vertebrate Circulatory System 2 Blood moves through the body in cycle, from the heart, through a system of vessels. Blood leaves the heart in arteries. From the arteries, blood passes into smaller arterioles. Tiny vessels called capillaries connect arterioles to venules, or small veins. Venules and then veins carry blood back to the heart. © McGraw Hill, LLC 10  Figure 24.3: The flow of blood through the circulatory system Access the text alternative for slide images. © McGraw Hill, LLC 11  24.2 Architecture of the Vertebrate Circulatory System 3 Although each capillary is very narrow, there are so many of them that the capillaries have the greatest total cross- sectional area of any other type of blood vessel. Capillary beds can be opened or closed based on the physiological needs of the tissues. © McGraw Hill, LLC 12  Figure 24.4: The capillary network connects arteries with veins Access the text alternative for slide images. © McGraw Hill, LLC 13  24.2 Architecture of the Vertebrate Circulatory System 4 An artery is more than a simple pipe. It needs to be able to expand with the pressure caused by contraction of the heart. Arterial walls have several layers. The innermost layer is endothelial cells. Next is a layer of elastic fibers surrounded by a layer of smooth muscle. The outermost layer is connective tissue. © McGraw Hill, LLC 14  Figure 24.5a: The structure of blood vessels Access the text alternative for slide images. © McGraw Hill, LLC 15  24.2 Architecture of the Vertebrate Circulatory System 5 Capillaries are where materials, like oxygen and food molecules, are exchanged between the blood and the body’s cells. Capillaries are narrow and have thin walls for exchange. Almost all cells of the vertebrate body are no more than 100 micrometers from a capillary. The blood pressure is far lower in the capillaries than in the arteries. © McGraw Hill, LLC 16  Capillary Structure Ed Reschke/Getty Images Figure 24.7: Red blood cells within a capillary Figure 24.5b: The structure of blood vessels Access the text alternative for slide images. © McGraw Hill, LLC 17  24.2 Architecture of the Vertebrate Circulatory System 6 Veins are vessels that return blood to the heart. The walls of veins are thinner because the blood pressure is not great. Veins have unidirectional valves that prevent the flow of blood backwards. © McGraw Hill, LLC 18  Structure of Veins Figure 24.5c: The structure of Figure 24.8: Flow of blood through blood vessels veins Access the text alternative for slide images. © McGraw Hill, LLC 19  24.3 Blood 1 Blood plasma is a complex solution of water with three kind of substances dissolved in it. Metabolites and wastes. For example—glucose, vitamins, hormones, etc. Salts and ions. Plasma ions—sodium, chloride, and bicarbonate Proteins. Proteins help keep water in the plasma. Serum albumin maintains osmotic balance. Other plasma proteins include antibodies, globulins, and fibrinogen. Fibrinogen converts into fibrin and is required for blood clotting. © McGraw Hill, LLC 20  Figure 24.9: Threads of fibrin Steve Gschmeissner/Science Photo Library/Getty Images © McGraw Hill, LLC 21  24.3 Blood 2 Nearly half the volume of blood is occupied by cells. The three principal cellular components are. Red blood cells. Hematocrit is the fraction of the total volume of the blood that is occupied by red blood cells. In humans, the hematocrit is usually about 45%. White blood cells. Platelets. © McGraw Hill, LLC 22  24.3 Blood 3 Red blood cells resemble flat disks with a central depression on both sides. Almost the entire interior is packed with hemoglobin, which carries oxygen. Because these cells have no nucleus they are short-lived and must be replaced by new cells synthesized in the bone marrow. © McGraw Hill, LLC 23  24.3 Blood 4 White blood cells contain no hemoglobin and are essentially colorless. There are several different kinds, all of which help defend the body against invading microorganisms and other foreign substances. Platelets are cell fragments, pinched from large cells in the bone marrow, called megakaryocytes, that play a key role in clotting. © McGraw Hill, LLC 24  Figure 24.10: Types of blood cells 1 Blood cell Life span in blood Function The life span of red blood cells is 120 days and its function is to transport oxygen and carbon dioxide transport. 120 days O2 and CO2 transport Red blood cell The lifespan of a neutrophil is 7 hours and its function is immune defenses. 7 hours Immune defenses Neutrophil The function of eosinophil is unknown and its function is a defense against parasites. Unknown Defense against parasites Eosinophil The lifespan of a basophil is unknown and its function is an inflammatory response. Unknown Inflammatory response Basophil © McGraw Hill, LLC 25  Figure 24.10: Types of blood cells 2 Blood cell Life span in blood Function Immune surveillance (precursor The lifespan of the monocyte is 3 days and the function is immune surveillance (precursor of tissue macrophage). 3 days of tissue macrophage) Monocyte Antibody production (precursor of The lifespan of a B lymphocyte is unknown and its function is antibody production (precursor of plasma cells). Unknown plasma cells) B lymphocyte The lifespan of T lymphocytes is unknown and its function is a cellular immune response. Unknown Cellular immune response T lymphocyte The lifespan of platelets is 7 to 8 days and its function in blood clotting. 7–8 days Blood clotting Platelets © McGraw Hill, LLC 26  24.4 Human Circulatory System 1 Humans and other mammals have a four-chambered heart with two complete pumping circuits. One side of the heart pumps blood to the lungs to pick up oxygen, while the other side distributes oxygenated blood to the rest of the body. © McGraw Hill, LLC 27  24.4 Human Circulatory System 2 In the human heart, Oxygen-rich blood returns from the lungs through pulmonary veins to the left atrium of the heart and flows mostly passively through the bicuspid (mitral) valve into the left ventricle. The thick-walled left ventricle contracts, sending oxygenated blood through a large artery called the aorta and out to the body. © McGraw Hill, LLC 28  24.4 Human Circulatory System 3 Blood travels through the body returning to the heart through the vena cavae, which drain into the right atrium. Blood flows from the right atrium through the tricuspid valve to the right ventricle. The right ventricle contracts, pushing blood through the pulmonary valve into pulmonary arteries that lead to the lungs. © McGraw Hill, LLC 29  Figure 24.11a: The heart and circulation in humans Access the text alternative for slide images. © McGraw Hill, LLC 30  Figure 24.11b: The heart and circulation in humans Access the text alternative for slide images. © McGraw Hill, LLC 31  24.4 Human Circulatory System 4 The simplest way to monitor heartbeat is to listen to it using a stethoscope. “Lub” is the sound made by the closing of the bicuspid and tricuspid valves at the start of ventricular contraction. “Dub” is the sound made by the closing of the pulmonary and aortic valves at the end of ventricular contraction. A heart murmur is heard if the valves do not fully close. © McGraw Hill, LLC 32  24.4 Human Circulatory System 5 Another way to examine the events of the heartbeat is to monitor the blood pressure. A device called a sphygmomanometer is used to measure the blood pressure in the brachial artery of the arm. Diastolic pressure is the low pressure when the atria are filling. Systolic pressure is the high pressure associated with the ventricles contracting. © McGraw Hill, LLC 33  Figure 24.12: Measuring blood pressure Access the text alternative for slide images. © McGraw Hill, LLC 34  24.4 Human Circulatory System 6 The contraction of the heart consists of a carefully orchestrated series of muscular contractions. First the atria contract, followed by the ventricles. The sinoatrial (SA) node in the wall of the right atrium is the site where each heartbeat originates. It is the pacemaker of the heart and determines the rhythm of the heart’s beating. © McGraw Hill, LLC 35  24.4 Human Circulatory System 7 Contraction of the atria is initiated by the SA node. The signal for contraction does not immediately spread to the ventricles because it must pass first through the atrioventricular (AV) node. This delays the signal for about 0.1 sec until the atria have finished contracting. © McGraw Hill, LLC 36  24.4 Human Circulatory System 8 The ventricles finally contract after the signal passes from the AV node to an atrioventricular bundle called the Bundle of His. The bundle branches and divides into fast-conducting Purkinje fibers which initiate the almost simultaneous contraction of the right and left ventricles. The electrical activity of the heart can be measured by a recording called an electrocardiogram (ECG or EKG). © McGraw Hill, LLC 37  Figure 24.13: How the mammalian heart contracts Access the text alternative for slide images. © McGraw Hill, LLC 38  24.5 Types of Respiratory Systems Respiration is the uptake of oxygen and release of carbon dioxide. Most primitive animal phyla obtain oxygen directly from their environments through diffusion. More advanced phyla have specific respiratory organs. Gills, tracheae, and lungs. © McGraw Hill, LLC 39  Figure 24.14: Gas exchange in animals Access the text alternative for slide images. © McGraw Hill, LLC 40  24.6 The Human Respiratory System 1 Lungs, although less efficient than gills, are adaptations to a terrestrial habitat. In mammals, a pair of lungs is housed in the thoracic cavity. Air first flows through the nasal cavity. It passes next through the pharynx, then the larynx (or voice box), then to the trachea, or windpipe. From there, air passes through several branchings of bronchi in the lungs and then to the bronchioles. The bronchioles lead to tiny air sacs called alveoli where gas exchange with the blood occurs. © McGraw Hill, LLC 41  Figure 24.15: The human respiratory system Access the text alternative for slide images. © McGraw Hill, LLC 42  24.6 The Human Respiratory System 2 The respiratory apparatus is simple in structure and functions as a one-cycle pump. A muscle called the diaphragm separates the thoracic cavity from the abdominal cavity. Each lung is covered by a thin, smooth membrane called the pleural membrane. This membrane adheres to another pleural membrane lining the walls of the thoracic cavity, basically coupling the lungs to the thoracic cavity wall. Air is drawn into the lungs by the creation of negative pressure. © McGraw Hill, LLC 43  24.6 The Human Respiratory System 3 The active pumping of air in and out is called breathing. During inhalation, muscular contractions cause the chest cavity to expand and the diaphragm to contract. When air pressure outside the lungs exceeds that within the lungs, air flows inward filling the lungs. During exhalation, the ribs and diaphragm return to their original positions. This puts pressure on the lungs and causes air pressure to become greater inside the lungs than outside the body. Air is expelled from the lungs. © McGraw Hill, LLC 44  Essential Biological Process 24A: Breathing Access the text alternative for slide images. © McGraw Hill, LLC 45  24.7 How Respiration Works: Gas Exchange 1 Oxygen moves through the circulatory system piggyback on the protein hemoglobin. Hemoglobin molecules contain iron and oxygen binds to it in a reversible way. Figure 24.16: The hemoglobin molecule Access the text alternative for slide images. © McGraw Hill, LLC 46  24.7 How Respiration Works: Gas Exchange 2 Hemoglobin molecules act like little sponges for oxygen. At the high O2 levels that occur in the blood supply at the lung, most hemoglobin molecules carry a full load of O2. In the tissues, the O2 levels are much lower, so hemoglobin gives up its bound oxygen. In the presence of CO2, the hemoglobin assumes a different shape that gives up its oxygen more readily. © McGraw Hill, LLC 47  24.7 How Respiration Works: Gas Exchange 3 CO2 must also be transported by the blood. About 8% simply dissolves in the plasma. 20% is bound to hemoglobin but at a different site than where O2 binds. The remaining 72% diffuses into the red blood cells. In order to maintain the gradient for CO2 to leave the tissues and enter the plasma, the CO2 levels in the plasma must be kept low. © McGraw Hill, LLC 48