© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey Chapter 23 Circulation

Introduction  In many animals, the pull of gravity influences the flow of blood through the body.  To regulate the pressure of blood in the head, the circulatory system of a giraffe uses –special valves, –saclike sinuses, and –other mechanisms.  In humans, special one-way valves in veins prevent blood from flowing back down the legs. © 2012 Pearson Education, Inc.

Figure 23.0_1 Chapter 23: Big Ideas Circulatory Systems The Human Cardiovascular System and Heart Structure and Function of Blood Vessels Structure and Function of Blood

Figure 23.0_2

CIRCULATORY SYSTEMS © 2012 Pearson Education, Inc.

23.1 Circulatory systems facilitate exchange with all body tissues  All cells must –receive nutrients, –exchange gases, and –remove wastes.  Diffusion alone is inadequate for large and complex bodies.  In most animals, circulatory systems facilitate these exchanges. © 2012 Pearson Education, Inc.

23.1 Circulatory systems facilitate exchange with all body tissues  An internal transport system assists diffusion by moving materials between –surfaces of the body and –internal tissues. © 2012 Pearson Education, Inc.

23.1 Circulatory systems facilitate exchange with all body tissues  A gastrovascular cavity in cnidarians and flatworms –promotes digestion and –distributes substances.  Most animals use a true circulatory system that consists of a –circulatory fluid (blood), –muscular pump (heart), and –set of tubes (blood vessels) to carry the fluid. © 2012 Pearson Education, Inc.

23.1 Circulatory systems facilitate exchange with all body tissues  Open circulatory systems are found in arthropods and many molluscs and consist of –a heart, –open-ended vessels, and –blood that directly bathes the cells and functions as the interstitial fluid. © 2012 Pearson Education, Inc.

Figure 23.1A Pores Tubular heart

23.1 Circulatory systems facilitate exchange with all body tissues  Closed circulatory systems are found in vertebrates, earthworms, squids, and octopuses and consist of –a heart and –vessels that confine blood, keeping it distinct from interstitial fluid. © 2012 Pearson Education, Inc.

23.1 Circulatory systems facilitate exchange with all body tissues  The vertebrate circulatory system is often called a cardiovascular system, including three types of vessels. 1. Arteries carry blood away from the heart. 2. Veins return blood to the heart. 3. Capillaries convey blood between arteries and veins. © 2012 Pearson Education, Inc.

23.1 Circulatory systems facilitate exchange with all body tissues  The cardiovascular system of a fish includes a heart with two main chambers: 1.The atrium receives blood from veins. 2.The ventricle pumps blood to gills via large arteries. These large arteries branch into –arterioles that give rise to –capillaries, the smallest blood vessels, which branch into networks called capillary beds. –Capillaries converge into venules, which in turn converge into larger veins. © 2012 Pearson Education, Inc.

Figure 23.1B Artery (O 2 -rich blood) Artery (O 2 -poor blood) Capillary beds Gill capillaries Arteriole Venule Vein Heart Atrium Ventricle

23.2 EVOLUTION CONNECTION: Vertebrate cardiovascular systems reflect evolution  A two-chambered heart –is characteristic of fish and –pumps blood in a single circulation in which blood moves –from gill capillaries, –to systemic capillaries, and –back to the heart. © 2012 Pearson Education, Inc.

Figure 23.2A Gill capillaries Body capillaries Heart: Ventricle Atrium

23.2 EVOLUTION CONNECTION: Vertebrate cardiovascular systems reflect evolution  Land vertebrates have a double circulation consisting of a separate –pulmonary circuit and –systemic circuit. © 2012 Pearson Education, Inc.

23.2 EVOLUTION CONNECTION: Vertebrate cardiovascular systems reflect evolution  Three-chambered hearts –are found in amphibians, turtles, snakes, and lizards and –consist of –two atria and –one undivided ventricle. –This arrangement generally separates oxygen-poor and oxygen-rich blood. © 2012 Pearson Education, Inc.

Figure 23.2B Ventricle Atrium Right Left Systemic circuit Atrium Systemic capillaries Lung and skin capillaries Pulmocutaneous circuit

23.2 EVOLUTION CONNECTION: Vertebrate cardiovascular systems reflect evolution  Four-chambered hearts –are found in crocodilians, birds, and mammals and –consist of –two atria and –two ventricles. –These two circuits do not mix –oxygen-rich and –oxygen-poor blood. © 2012 Pearson Education, Inc.

Figure 23.2C Systemic capillaries Lung capillaries Ventricle Atrium Ventricle Atrium Right Left Systemic circuit Pulmonary circuit

THE HUMAN CARDIOVASCULAR SYSTEM AND HEART © 2012 Pearson Education, Inc.

23.3 The human cardiovascular system illustrates the double circulation of mammals  Blood flow through the double circulatory system of humans –drains from the superior vena cava (from the head and arms) or inferior vena cava (from the lower trunk and legs) into the right atrium, –moves out to the lungs via the pulmonary artery, –returns to the left atrium through the pulmonary vein, and –leaves the heart through the aorta. © 2012 Pearson Education, Inc. Animation: Path of Blood Flow in Mammals

Figure 23.3A Superior vena cava Pulmonary artery Capillaries of right lung Pulmonary vein Right atrium Right ventricle Inferior vena cava Aorta Capillaries of head, chest and arms Pulmonary artery Capillaries of left lung Pulmonary vein Left atrium Left ventricle Aorta Capillaries of abdominal region and legs

Figure 23.3B To lung Right atrium From lung Semilunar valve Atrioventricular (AV) valve To lung Left atrium From lung Semilunar valve Atrioventricular (AV) valve Left ventricle Right ventricle

23.4 The heart contracts and relaxes rhythmically  The repeated contraction and relaxation of pumping blood is called the cardiac cycle. The cycle consists of two main phases. 1.During diastole, blood flows –from veins –into heart chambers. 2.During systole, blood flows –from atria –into ventricles. © 2012 Pearson Education, Inc.

Figure 23.4_s1 Diastole The heart is relaxed. The semilunar valves are closed. The AV valves are open. 0.4 sec 1

Figure 23.4_s2 Diastole Systole The heart is relaxed. The semilunar valves are closed. The atria contract. The AV valves are open. 0.4 sec 0.1 sec 21

Figure 23.4_s3 Diastole Systole The heart is relaxed. The semilunar valves are closed. The atria contract. The ventricles contract. The semilunar valves are open. The AV valves are closed. The AV valves are open. 0.4 sec 0.3 sec 0.1 sec 231

23.4 The heart contracts and relaxes rhythmically  Cardiac output is the amount of blood pumped per minute from the ventricles.  Heart rate is the number of heart beats per minute.  Heart valves prevent the backflow of blood.  A heart murmur –is a defect in one or more heart valves that –permits a backflow of blood and –reduces the cardiac output. © 2012 Pearson Education, Inc.

23.5 The SA node sets the tempo of the heartbeat  The SA (sinoatrial) node –generates electrical signals in atria and –sets the rate of heart contractions.  The AV (atrioventricular) node –relays these signals to the ventricles and –causes ventricular contraction. © 2012 Pearson Education, Inc.

Figure 23.5A 3124 ECG Apex Right atrium SA node (pacemaker) AV node Specialized muscle fibers Signals from the SA node spread through the atria. Signals are delayed at the AV node. Specialized muscle fibers pass signals to the heart apex. Signals spread throughout the ventricles.

Figure 23.5A_1 2 ECG Right atrium SA node (pacemaker) AV node Signals from the SA node spread through the atria. Signals are delayed at the AV node. 1

Figure 23.5A_2 34 Apex Specialized muscle fibers Specialized muscle fibers pass signals to the heart apex. Signals spread throughout the ventricles.

23.5 The SA node sets the tempo of the heartbeat  An electrocardiogram (ECG) records electrical changes in the heart.  Heart rates normally adjust to body needs.  Abnormal rhythms may occur in a heart attack.  Automatic external defibrillators (AEDs) –shock the heart, –reset the SA node, and –save thousands of lives. © 2012 Pearson Education, Inc.

Figure 23.5B Artificial pacemaker Wire leading to SA node Heart

23.6 CONNECTION: What is a heart attack?  A heart attack –is damage or death of cardiac muscle and –usually results from a blocked coronary artery.  Cardiovascular diseases are disorders of the heart and blood vessels. These include 1. a stroke, death of brain tissue from blocked or ruptured arteries in the head, and 2. atherosclerosis, in which fatty deposits in the walls of arteries narrow the blood vessels and restrict blood flow. © 2012 Pearson Education, Inc.

Figure 23.6A Superior vena cava Pulmonary artery Right coronary artery Aorta Left coronary artery Blockage Dead muscle tissue

Figure 23.6B Connective tissue Smooth muscle Epithelium Plaque

Figure 23.6B_1 Connective tissue Smooth muscle Epithelium

Figure 23.6B_2 Plaque

STRUCTURE AND FUNCTION OF BLOOD VESSELS © 2012 Pearson Education, Inc.

23.7 The structure of blood vessels fits their functions  Capillaries –have thin walls consisting of a single layer of epithelial cells, –are narrow, about as wide as one red blood cell, and –increase surface area for gas and fluid exchange with the interstitial fluid. © 2012 Pearson Education, Inc.

Figure 23.7A Capillary Red blood cell

Figure 23.7B Capillary Interstitial fluid Tissue cell Diffusion of molecules

23.7 The structure of blood vessels fits their functions  Arteries and veins –are lined by a single layer of epithelial cells and –have elastic fibers in an outer connective tissue layer that allows these vessels to recoil after stretching. –Arteries contain a thick layer of smooth muscle in their walls that can constrict and reduce blood flow. –Veins have one-way valves that restrict backward flow of blood. © 2012 Pearson Education, Inc.

Figure 23.7C Capillary Epithelium Smooth muscle Epithelium Smooth muscle Basal lamina Connective tissue Artery ArterioleVenule Vein Valve

23.8 Blood pressure and velocity reflect the structure and arrangement of blood vessels  Blood pressure –is the force blood exerts on vessel walls, –depends on cardiac output and resistance of vessels to expansion, and –decreases as blood moves away from the heart. © 2012 Pearson Education, Inc.

Figure 23.8A Systolic pressure Diastolic pressure Relative sizes and numbers of blood vessels Pressure (mm Hg) Velocity (cm/sec) Aorta Arteries Arterioles Capillaries Venules Veins Venae cavae

23.8 Blood pressure and velocity reflect the structure and arrangement of blood vessels  Blood pressure is –highest in arteries and –lowest in veins.  Blood pressure is measured as –systolic pressure—caused by ventricular contraction, and –diastolic pressure—low pressure between contractions. © 2012 Pearson Education, Inc.

23.8 Blood pressure and velocity reflect the structure and arrangement of blood vessels  How does blood travel against gravity, up legs? –Veins are squeezed by pressure from muscle contractions between –two muscles or –muscles and bone or skin. –One-way valves limit blood flow to one direction, toward the heart. © 2012 Pearson Education, Inc.

Figure 23.8B Direction of blood flow in vein Valve (open) Contracting skeletal muscle Valve (closed)

23.9 CONNECTION: Measuring blood pressure can reveal cardiovascular problems  A typical blood pressure for a healthy young adult is about 120/70.  Blood pressure is commonly measured using a sphygmomanometer.  Hypertension is a serious cardiovascular problem in which blood pressure is persistent at or above –140 systolic and/or –90 diastolic. © 2012 Pearson Education, Inc.

Figure 23.9_s1 Typical blood pressure: 120 systolic 70 diastolic Rubber cuff inflated with air Artery Artery closed 21 Pressure in the cuff above

Figure 23.9_s2 Typical blood pressure: 120 systolic 70 diastolic Rubber cuff inflated with air Artery Artery closed Pressure in the cuff above 120 Pressure in the cuff at 120 Sounds audible in the stethoscope

Figure 23.9_s3 Typical blood pressure: 120 systolic 70 diastolic Rubber cuff inflated with air Artery Artery closed Pressure in the cuff above 120 Pressure in the cuff at 120 Pressure in the cuff at 70 Sounds audible in the stethoscope Sounds stop 2134

23.9 CONNECTION: Measuring blood pressure can reveal cardiovascular problems  Hypertension causes –the heart to work harder, weakening the heart over time, –increased plaque formation from tiny ruptures, and –increased risk of blood clot formation.  Hypertension can contribute to –heart attacks, –strokes, and/or –kidney failure. © 2012 Pearson Education, Inc.

23.10 Smooth muscle controls the distribution of blood  Blood flow through capillaries i s restricted by precapillary sphincters.  By opening and closing these precapillary sphincters, blood flow to particular regions can be increased or decreased.  Only about 5–10% of capillaries are open at one time. © 2012 Pearson Education, Inc.

Figure Sphincters are contracted. Sphincters are relaxed. Precapillary sphincters Thoroughfare channel Arteriole Capillaries Venule Arteriole Thoroughfare channel

23.11 Capillaries allow the transfer of substances through their walls  Capillaries have very thin walls.  Substances leave blood and enter interstitial fluid by –diffusion and –pressure-driven flow through clefts between epithelial cells.  Blood pressure forces fluid out of capillaries at the arterial end.  Osmotic pressure draws in fluid at the venous end. © 2012 Pearson Education, Inc.

Figure 23.11A Capillary wall Capillary lumen Interstitial fluid Nucleus of epithelial cell Clefts between the cells Muscle cell

Figure 23.11A_1 Capillary wall Capillary lumen Interstitial fluid Nucleus of epithelial cell Clefts between the cells Muscle cell

Figure 23.11B Tissue cells Fluid enters a lymph vessel Venous end Osmotic pressure Blood pressure Arterial end Interstitial fluid Net fluid movement out of the capillary

STRUCTURE AND FUNCTION OF BLOOD © 2012 Pearson Education, Inc.

23.12 Blood consists of red and white blood cells suspended in plasma  Blood consists of several types of cells suspended in a liquid called plasma, which –is about 90% water and –contains many different substances. © 2012 Pearson Education, Inc.

Figure 23.12_1 Plasma (55%) Constituent Major functions WaterSolvent for carrying other substances Ions (blood electrolytes) Sodium Potassium Calcium Magnesium Chloride Bicarbonate Osmotic balance, pH buffering, and maintaining ion concentration of interstitial fluid Plasma proteins Fibrinogen Immunoglobulins (antibodies) Osmotic balance and pH buffering Clotting Defense Substances transported by blood Nutrients (e.g., glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones

23.12 Blood consists of red and white blood cells suspended in plasma  Two classes of cells are suspended in blood plasma. 1.Red blood cells or erythrocytes transport O 2 bound to hemoglobin. 2.White blood cells, or leukocytes, –function inside and outside the circulatory system and –fight infections and cancer. –Monocytes and neutrophils are white blood cells called phagocytes, which engulf and digest bacteria and debris from our own dead cells. © 2012 Pearson Education, Inc.

Figure 23.12_2 Cellular elements (45%) Cell typeNumber per  L (mm 3 ) of blood) Functions Transport of O 2 and some CO 2 5–6 million Red blood cells (erythrocytes) White blood cells (leukocytes) 5,000–10,000Defense and immunity Platelets 250,000– 400,000 Blood clotting Basophils Eosinophils Lymphocytes Neutrophils Monocytes

Figure Plasma (55%) Cellular elements (45%) ConstituentMajor functions Water Solvent for carrying other substances Ions (blood electrolytes) Sodium Potassium Calcium Magnesium Chloride Bicarbonate Osmotic balance, pH buffering, and maintaining ion concentration of interstitial fluid Plasma proteins Fibrinogen Immunoglobulins (antibodies) Osmotic balance and pH buffering Clotting Defense Substances transported by blood Nutrients (e.g., glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones Centrifuged blood sample Cell typeNumber per  L (mm 3 ) of blood) Functions Transport of O 2 and some CO 2 5–6 million Red blood cells (erythrocytes) White blood cells (leukocytes) 5,000–10,000Defense and immunity Platelets 250,000– 400,000 Blood clotting Basophils Eosinophils Lymphocytes Neutrophils Monocytes

23.13 CONNECTION: Too few or too many red blood cells can be unhealthy  Anemia can be caused by low amounts of –hemoglobin or –red blood cells. –Anemia causes fatigue due to lack of oxygen in tissues. © 2012 Pearson Education, Inc.

23.13 CONNECTION: Too few or too many red blood cells can be unhealthy  The hormone erythropoietin (EPO) regulates red blood cell production.  Some athletes artificially increase red blood cell production by –training at high altitudes, –injecting erythropoietin, and –withdrawing, storing, and then reinjecting their blood cells just before a competition. –Abuse of these methods can lead to clotting, stroke, heart failure, or even death. © 2012 Pearson Education, Inc.

Figure 23.13

23.14 Blood clots plug leaks when blood vessels are injured  When a blood vessel is damaged –platelets rapidly adhere to the exposed connective tissue and –a cluster of sticky platelets forms a plug. –Clotting factors released from platelets and in the plasma help trigger the conversion of the plasma protein fibrinogen to fibrin, a threadlike protein that helps form a clot that plugs the leak. © 2012 Pearson Education, Inc.

Figure 23.14A_s1 1 Platelets adhere. Epithelium Connective tissue Platelet

Figure 23.14A_s2 21 Platelets adhere. A platelet plug forms. Epithelium Connective tissue Platelet Platelet plug

Figure 23.14A_s3 321 Platelets adhere. A platelet plug forms. A fibrin clot forms. Epithelium Connective tissue Platelet Platelet plug Fibrin clot

23.14 Blood clots plug leaks when blood vessels are injured  Within an hour after a fibrin clot forms, the platelets contract, pulling the torn edges closer together.  Chemicals released by platelets also stimulate cell division in smooth muscle and connective tissue, initiating the healing process. © 2012 Pearson Education, Inc.

Figure 23.14B

23.15 CONNECTION: Stem cells offer a potential cure for blood cell diseases  Multipotent stem cells –are unspecialized and –replace themselves throughout the life of an organism.  Multipotent stem cells can differentiate into two main types of stem cells. 1.Lymphoid stem cells can in turn produce two types of lymphocytes, which function in the immune system. 2.Myeloid stem cells can differentiate into –erythrocytes, –other white blood cells, and –platelets. © 2012 Pearson Education, Inc.

Figure Lymphocytes Monocytes Neutrophils Eosinophils Basophils Myeloid stem cells Platelets Erythrocytes Lymphoid stem cells Multipotent stem cells (in bone marrow)

23.15 CONNECTION: Stem cells offer a potential cure for blood cell diseases  Leukemia –is cancer of white blood cells, –results in extra leukocytes that do not function properly, and –is usually fatal unless treated.  Leukemia may be treated by –radiation, –chemotherapy, or –the replacement of cancerous bone marrow with healthy bone marrow. © 2012 Pearson Education, Inc.

You should now be able to 1.Describe the general functions of a circulatory system. 2.Compare the structures and functions of gastrovascular cavities, open circulatory systems, and closed circulatory systems. 3.Compare the cardiovascular systems of a fish, an amphibian, a reptile, a bird, and a mammal. 4.Describe the pathway of blood through the mammalian cardiovascular system. © 2012 Pearson Education, Inc.

You should now be able to 5.Distinguish between diastole and systole. 6.Explain how heartbeats are controlled. 7.Define a heart attack and cardiovascular disease. 8.Relate the structure of blood vessels to their function. 9.Explain how and why blood pressure changes as blood moves away from the heart. 10.Explain how blood is moved back to the heart. © 2012 Pearson Education, Inc.

You should now be able to 11.Explain how blood pressure is measured. Give examples of normal and high blood pressure readings. 12.Explain how blood flow through capillaries is regulated. 13.Explain how the structure of a capillary relates to its functions. 14.Describe the components of blood and their functions. © 2012 Pearson Education, Inc.

You should now be able to 15.Describe the structure, function, and production of red blood cells. 16.Describe the process of blood clotting. 17.Define leukemia and describe the most common forms of treatment. © 2012 Pearson Education, Inc.

Figure 23.UN01 Artery Vein Valve Basal lamina Capillary Epithelium Smooth muscle Connective tissue

Figure 23.UN02 a. b. c. d. e. f. g. h. i. j. k. l. m. n. o. p.

Figure 23.UN03 a. b.