1. BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor From PowerPoint ® Lectures for Biology: Concepts & Connections CHAPTER 23 Circulation Modules 23.1 – 23.3

2. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings As with all land animals, the giraffe and the corn snake are constantly subject to the force of gravity How Does Gravity Affect Blood Circulation?

3. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The circulatory system keeps blood pumping despite gravity’s pull –Muscle contractions help blood travel uphill in the veins of a giraffe’s long legs –The wriggling of the corn snake squeezes its veins and increases circulation

4. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Most animals have a circulatory system –It transports O 2 and nutrients to cells –It takes away CO 2 and other wastes

5. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Capillaries are microscopic blood vessels –They form an intricate network among the tissue cells 23.1 The circulatory system associates intimately with all body tissues Figure 23.1A Red blood cell Capillary

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings –No substance has to diffuse far to enter or leave a cell Figure 23.1B Capillary INTERSTITIAL FLUID Tissue cell Diffusion of molecules

7. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings In cnidarians and flatworms, the gastrovascular cavity functions in both –digestion –internal transport 23.2 Several types of internal transport have evolved in animals MECHANISMS OF INTERNAL TRANSPORT Figure 23.2A Mouth Circular canal

8. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Most animals have a separate circulatory system, either open or closed Open systems –A heart pumps blood through open-ended vessels into spaces between cells Figure 23.2B Pores Tubular heart

9. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Closed systems –A heart pumps blood through arteries and capillary beds –The blood returns to the heart via veins Figure 23.2C Artery (O 2 -rich blood) Arteriole Capillary beds Venule Vein Atrium Ventricle Heart Artery (O 2 -poor blood) Gill capillaries

10. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A fish has a single circuit of blood flow 23.3 Vertebrate cardiovascular systems reflect evolution Figure 23.3A Gill capillaries Heart: Ventricle (V) Atrium (A) Systemic capillaries

11. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The cardiovascular system of land vertebrates has two circuits The pulmonary circuit –conveys blood between the heart and gas- exchange tissues The systemic circuit –carries blood between the heart and the rest of the body Figure 23.3B PULMONARY CIRCUIT A Systemic capillaries Lung capillaries V Right SYSTEMIC CIRCUIT A V Left

12. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The mammalian heart has two thin-walled atria that pump blood into the ventricles –The thick-walled ventricles pump blood to all other body organs 23.4 The human heart and cardiovascular system typify those of mammals THE MAMMALIAN CARDIOVACULAR SYSTEM

13. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 23.4A Pulmonary artery Superior vena cava RIGHT ATRIUM Pulmonary veins Semilunar valve Atrioventricular valve Inferior vena cava Aorta Pulmonary artery LEFT ATRIUM Pulmonary veins Semilunar valve Atrioventricular valve RIGHT VENTRICLE LEFT VENTRICLE

14. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 23.4B RIGHT VENTRICLE 1 2 3 Capillaries of right lung 3 Capillaries of left lung 4 LEFT ATRIUM 5 LEFT VENTRICLE 6 Aorta 7 Capillaries of Head and arms 8 Capillaries of abdominal organs and legs 9 Superior vena cava 10 Inferior vena cava 11 RIGHT ATRIUM Pulmonary vein Aorta Pulmonary vein Pulmonary artery

15. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A single layer of epithelial cells forms capillary walls Arteries and veins have smooth muscle and connective tissue –Valves in veins prevent the backflow of blood 23.5 The structure of blood vessels fits their functions

16. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 23.5 Epithelium Smooth muscle Connective tissue ARTERY ARTERIOLE CAPILLARY EpitheliumBasement membrane Epithelium Smooth muscle Connective tissue Valve VEIN VENULE

17. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Diastole –Blood flows from the veins into the heart chambers 23.6 The heart contracts and relaxes rhythmically Figure 23.6 Heart is relaxed. AV valves are open. 1 2 3 Atria contract. Ventricles contract. Semilunar valves are open. SYSTOLE DIASTOLE 0.4 sec 0.1 sec 0.3 sec Systole –The atria briefly contract and fill the ventricles with blood –Then the ventricles contract and propel blood out

18. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Heart valves prevent backflow Cardiac output –The amount of blood pumped into the aorta by the left ventricle per minute

19. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The SA node (pacemaker) generates electrical signals that trigger the contraction of the atria The AV node then relays these signals to the ventricles 23.7 The pacemaker sets the tempo of the heartbeat Figure 23.7 Pacemaker (SA node) 1234 Right atrium Right ventricle AV node Specialized muscle fibers ECG

20. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings An electrocardiogram (ECG) is a recording of electrical changes in the skin resulting from the electrical signals in the heart –Control centers in the brain adjust heart rate to body needs

21. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A heart attack is damage that occurs when a coronary feeding the heart is blocked 23.8 Connection: What is a heart attack? Figure 23.8A Right coronary artery Aorta Left coronary artery Blockage Dead muscle tissue

22. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Blood vessel blockage is usually due to blood clots Figure 23.8B Connective tissue Smooth muscle EpitheliumPlaque

23. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Blood pressure depends on –cardiac output –resistance of vessels 23.9 Blood exerts pressure on vessel walls

24. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Pressure is highest in the arteries –It drops to zero by the time the blood reaches the veins Figure 23.9A Diastolic pressure Systolic pressure Relative sizes and numbers of blood vessels

25. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Three factors keep blood moving back to the heart –muscle contractions –breathing –one-way valves Figure 23.9B Direction of blood flow in vein Valve (closed) Skeletal muscle Valve (open)

26. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Blood pressure is measured as systolic and diastolic pressures 23.10 Connection: Measuring blood pressure can reveal cardiovascular problems Figure 23.10 Blood pressure 120 systolic 80 diastolic (to be measured) 1 234 Rubber cuff inflated with air Pressure in cuff below 120 Pressure in cuff below 80 Artery Pressure in cuff above 120 Sounds audible in stethoscope Sounds stop Artery closed

27. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Hypertension is persistent systolic pressure higher than 140 mm Hg and/or diastolic pressure higher than 90 mm Hg –It is a serious cardiovascular problem

28. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Muscular constriction of arterioles and precapillary sphincters controls the flow through capillaries 23.11 Smooth muscle controls the distribution of blood Figure 23.11 1 Sphincters relaxed 2 Sphincters contracted Precapillary sphinctersThoroughfare channel Capillaries ArterioleVenuleArteriole Venule Thoroughfare channel

29. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 23.12 Capillaries allow the transfer of substances through their walls Figure 23.12A

30. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The transfer of materials between the blood and interstitial fluid can occur by –leakage through clefts in the capillary walls –diffusion through the wall –blood pressure –osmotic pressure

31. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 23.12B Arterial end of capillary Tissue cells Osmotic pressure INTERSTITIAL FLUID NET PRESSURE OUT Blood pressure Osmotic pressure Venous end of capillary NET PRESSURE IN

32. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Plasma is an aqueous solution of various substances 23.13 Blood consists of cells suspended in plasma STRUCTURE AND FUNCTION OF BLOOD

33. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 23.13 Withdraw blood Place in tube PLASMA 55% CONSTITUENTMAJOR FUNCTIONS Water Solvent for carrying other substances Salts Osmotic balance, pH buffering, and regulation of membrane permeability Sodium Potassium Calcium Magnesium Chloride Bicarbonate Plasma proteins Osmotic balance, pH buffering Clotting Immunity Albumin Fibrinogen Immunoglobins (antibodies) Substances transported by blood Nutrients (e.g., glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones Centrifuge CELLULAR ELEMENTS 45% CELL TYPENUMBER (per mm 3 of blood) FUNCTIONS Erythrocytes (red blood cells) 5–6 millionTransport of oxygen (and carbon dioxide) Leukocytes (white blood cells) 5,000–10,000 Defense and immunity Basophil Eosinophil Neutrophil Lymphocyte Monocyte Platelets 250,000– 400,000 Blood clotting

34. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 23.14 Red blood cells transport oxygen Figure 23.14 Red blood cells contain hemoglobin –Hemoglobin enables the transport of O 2

35. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 23.15 White blood cells help defend the body Figure 23.15 White blood cells function both inside and outside the circulatory system –They fight infections and cancer Basophil Neutrophil Monocyte Eosinophil Lymphocyte

36. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 23.16 Blood clots plug leaks when blood vessels are injured Figure 23.16B When a blood vessel is damaged, platelets respond –They help trigger the formation of an insoluble fibrin clot that plugs the leak

37. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 23.16A Platelet releases chemicals that make nearby platelets sticky Injury to lining of blood vessel exposes connective tissue; platelets adhere 123 Platelet plug formsFibrin clot traps blood cells Connective tissue Platelet plug Clotting factors from: Platelets Damaged cells Calcium and other factors in blood plasma ProthrombinThrombin FibrinogenFibrin

38. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 23.17 Connection: Stem cells offer a potential cure for leukemia and other blood cell diseases Figure 23.17 All blood cells develop from stem cells in bone marrow –Such cells may prove valuable for treating certain blood disorders