Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. BIOLOGY A GUIDE TO THE NATURAL WORLD FOURTH EDITION DAVID KROGH Transport and Exchange 1: Blood and Breath
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Cardiovascular System
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Cardiovascular System The human cardiovascular system is a fluid transport system that consists of the heart, all the body’s blood vessels, the blood, and the bone marrow tissue in which red blood cells are formed.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Cardiovascular System This system transports substances both to and from the body’s cells. Such substances include oxygen, carbon dioxide, nutrients, vitamins, hormones, waste products, and immune system cells and proteins.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Transport and Exchange System Figure 29.1 Digestive system transforms food into a form that can be transported throughout the body. Urinary system filters bodily fluids, removes waste while conserving water and other materials. Cardiovascular system transports materials to and from all other systems. Respiratory system moves O 2 into, and CO 2 out of the body.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Composition of Blood
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Composition of Blood Blood has two primary components: formed elements and blood plasma. Formed elements are blood cells and cell fragments. Blood plasma is the fluid portion of blood in which the formed elements are suspended.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Composition of Blood There are three kinds of formed elements: –red blood cells –white blood cells –platelets
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Composition of Blood Figure 29.2 blood sample formed elements plasma 55% 99.9% 0.1% 45% Formed elements Plasma Red blood cellsWhite blood cellsPlatelets Red blood cells White blood cells Platelets 92% 7% 1% Water Plasma proteins Other solutes
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Composition of Blood Red blood cells carry oxygen to, and carbon dioxide from, every part of the body. White blood cells are central to the immune system. Platelets are small fragments of cells that are important in the blood-clotting process.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Transport Cells Figure 29.3
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Plasma Blood plasma is 92 percent water, but it also contains other materials, including proteins.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Plasma There are three primary classes of plasma proteins: –Albumins, which transport hormones and fatty acids. –Fibrinogen, which aids in blood clotting. –Globulins, which aid the immune system and serve as transport proteins.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Transport Proteins Two transport proteins are important in the health of the heart. Low-density lipoproteins (LDLs) carry lipids to bodily tissues from the liver and small intestines. High-density lipoproteins (HDLs) carry lipids from these tissues to the liver.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Plasma Other plasma compounds include nutrients, wastes, hormones, and electrolytes.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Blood Vessels
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Blood Vessels Blood vessels carrying blood away from the heart are arteries; blood vessels returning blood to the heart are veins.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Blood Vessels The smallest blood vessels, the capillaries, connect the arteries with the veins.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Blood Vessels Figure 29.4 epithelium artery capillary vein muscle connective tissue epithelium muscle connective tissue
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Blood Vessels Arteries and veins are always made of three distinct layers of tissue. The middle layer is muscle that allows arteries and veins to widen or constrict in diameter.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Blood Vessels Capillaries, conversely, are composed of only a single layer of cells. This allows the movement of blood-borne materials into and out of them along their length.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Heart and Blood Circulation
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Heart and Blood Circulation The heart’s contractions propel blood out to the various tissues of the body.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Heart and Blood Circulation Two blood circulation loops exist in the body. The first loop is the pulmonary circulation, in which blood circulates between the heart and the lungs (with the result that blood is oxygenated).
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Heart and Blood Circulation The second loop is the systemic circulation, in which blood circulates between the heart and the rest of the body. The result is that needed materials are transported to and from all parts of the body.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Heart and Blood Circulation Figure 29.5 pulmonary circulation (to lungs) systemic circulation (to all tissues) superior vena cava inferior vena cava The left side of the heart pumps oxygenated blood to the entire body. pulmonary arteries pulmonary veins systemic arteries systemic veins The right side of the heart pumps deoxygenated blood to the lungs. The pulmonary and systemic circulation networksThe circulation of blood through the heart Deoxygenated blood enters the right atrium through the superior and inferior vena cavae. The right atrium pumps blood into the right ventricle, which contracts, pumping blood to the lungs. Blood is delivered to the lungs via the pulmonary arteries. Oxygenated blood returns from the lungs through the pulmonary veins. Blood then moves into the left atrium which pumps it into the left ventricle. Powerful contractions of the left ventricle force blood into the aorta. From the aorta, blood is distributed to the rest of the body.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Heart and Blood Circulation The human heart contains four muscular chambers: –Two for pulmonary circulation (the right atrium and right ventricle). –Two for systemic circulation (the left atrium and left ventricle).
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Heart and Blood Circulation A series of valves that open and close ensures that blood flows only one way through the heart.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Cardiovascular System PLAY Animation 29.1: The Cardiovascular System
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings What is a Heart Attack?
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Heart Attacks About half of all deaths in the United States today are caused by the blockage of one or more of the coronary arteries that supply heart tissue with blood.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Heart Attacks Such blockages generally are caused by a buildup of low-density lipoprotein (LDL) molecules in a coronary artery, followed by an immune system reaction to these LDLs and formation of a blood clot in the artery.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Heart Attacks A heart attack occurs when this process results in the complete blockage of a coronary artery, which cuts off the blood supply to groups of cells within the heart, thus killing them.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Critical Vessels Figure 29.6 superior vena cava right coronary artery left main coronary artery left anterior descending coronary artery pulmonary artery aorta site of blockage damaged heart muscle blood clot core of oxidized LDL molecules
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Distributing the Goods: The Capillary Beds
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Capillary Beds Arteries near the heart branch into smaller arterioles, which feed into the delivery vehicles of the cardiovascular system, the capillary beds.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds The capillary beds then feed back into the body’s system of veins that returns blood to the heart.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds Figure 29.7 artery capillary bed vein epithelial cells of capillary wall tissue cells interstitial fluid CO 2 wastes venule arteriole O 2 glucose
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds Materials needed by the body’s tissues move out of the capillaries and into the interstitial fluid that surrounds both the capillaries and nearby cells. Meanwhile, carbon dioxide and wastes from these cells flow into capillaries from the interstitial fluid.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds The movement of all these substances is aided by their concentration gradients. They move from areas of their higher concentration to areas of their lower concentration. The movement of water is driven in two directions by two opposing forces.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds At the arterial end of the capillary beds, blood pressure tends to drive water out of the capillaries. But at the venous end of the beds, osmosis overcomes the force of blood pressure and pulls most of this water back into the capillaries.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds Blood pressure is at low levels by the time blood has moved through the capillaries.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Capillary Beds Blood returns to the heart through the contraction of skeletal muscles, which squeeze the veins in a way that moves the venous blood toward the heart. A system of valves in the veins ensures that this movement is one way—toward the heart.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. One-Way Flow to the Heart Figure 29.8 Valves allow blood to go forward but not backward valve open valve closed muscles contracted muscles relaxed
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Respiratory System
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System The central function of the respiratory system is to capture oxygen and to dispose of carbon dioxide. It also aids in controlling pH balance in the bloodstream and in producing sounds for speaking.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System Respiration can be defined as the exchange of gases between the atmosphere outside the body and the cells within it.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System The respiratory system includes: –the lungs, the nose, nasal cavity, and sinuses –the pharynx (upper throat) –the larynx (voice box) –the trachea (windpipe) –the conducting passageways, called bronchi and bronchioles, that lead to the lungs
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System The lungs themselves are largely composed of the tiny hollow sacs, called alveoli. Alveoli lie at the end of each bronchiole and they are the air exchange chambers of the body.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System Figure 29.9 sinuses pharynx esophagus right lung diaphragm nasal cavity trachea left lung left bronchus bronchioles vein artery alveolus capillary network larynx Anatomy of the lungs The structure of alveoli A bronchiole and its alveoli
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System The enormous surface area of the alveoli and their associated capillaries is used for the exchange of oxygen and carbon dioxide.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Steps in Respiration
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Steps in Respiration The first step in respiration is breathing or ventilation, meaning the physical movement of air into and out of the lungs.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Ventilation Figure inhalationexhalation respiratory cycle lungs ribs diaphragm Elevation of rib cage and contraction of diaphragm decrease pressure in the lungs, causing air to flow in. Depression of rib cage and elevation of diaphragm increase pressure in lungs causing air to flow out.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Steps in Respiration Once in the lungs, oxygen diffuses across the thin wall of an alveolus into an adjacent capillary and binds with hemoglobin protein in red blood cells.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Steps in Respiration Oxygen then moves with the blood cells to the heart. The heart pumps the blood to body tissues, where the oxygen diffuses into the interstitial fluid and then into nearby cells.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Steps in Respiration The carbon dioxide produced in the body’s cells moves into nearby capillaries, to be carried to the lungs.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Gas Exchange in the Body Figure O2O2 capillary tissue cell CO 2 air out air in O2O2 alveolus in lung CO 2
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Steps in Respiration All the oxygen loaded into red blood cells binds initially with the hemoglobin in them. Carbon dioxide is transported both within red blood cells and in blood plasma.
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Respiratory System PLAY Animation 29.2: The Respiratory System