BIOLOGY. CONCEPTS & CONNECTIONS Fourth Edition. Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor. CHAPTER 23 Circulation

Transcription

1 BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor CHAPTER 23 Circulation Modules From PowerPoint Lectures for Biology: Concepts & Connections

2 How Does Gravity Affect Blood Circulation? As with all land animals, the giraffe and the corn snake are constantly subject to the force of gravity

3 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 What is the job of a transport, or circulatory system? All organisms have to transport and move materials from place to place. They may not need a system to accomplish that task As long as all parts of the organism touch the environment a system is NOT needed to accomplish tasks.

5 How do the lower organisms transport materials? Protozoa: unicellular, eukaryotic, all parts of the organism touch the environment, movement of the cytoplasm (cyclosis, cytoplasmic streaming) moves stuff around the protists. Stuff includes Oxygen (O 2 ) gas, Carbon Dioxide (CO 2 )gas, nutrients from food and wastes from metabolism

6 MECHANISMS OF INTERNAL TRANSPORT Several types of internal transport have evolved in animals In cnidarians and flatworms, the gastrovascular cavity functions in both digestion internal transport Mouth Circular canal Figure 23.2A

7 The Cnidarians have 2 cell layers Inner: endoderm/gastroderm Outer: ectoderm All cells touch the environment because these organisms are hollow Do not need a complex transport system to move materials.

8 Aurelia jelly Figure 23.2Ax

9 Most animals have a separate circulatory system, either open or closed

10 Open systems Blood is not always found in vessels/tubes, one dorsal heart pumps blood through open-ended vessels into spaces (sinuses) between cells, blood does not transport oxygen, has no hemoglobin, blood is also called hemolymph, movement aided by muscle contractions and movement Pores Tubular heart Figure 23.2B

11 Closed circulatory system: blood always found in transport vessels (tubes), blood always under pressure (being pushed by a pump), blood carries O2 using hemoglobin. Hemoglobin: iron containing protein & pigment. When O2 combines with hemoglobin the blood becomes a bright red (crimson) color

12 Many animals have a segmented body Earthworms (annelid): segmented worms, have 5 pairs of aortic arches (accessory hearts) Brain Main heart Coelom Anus Mouth Digestive tract Segment walls Accessory heart Nerve cord Blood vessels Excretory organ Figure 18.10A

13 Fish (b0ny fish): vertebrata, closed circulatory system, simple heart (2 chambers) Arteriole Capillary beds Artery (O 2 -rich blood) Venule Vein Gill capillaries Artery (O 2 -poor blood) Atrium Ventricle Heart Figure 23.2C

14 STRUCTURE AND FUNCTION OF BLOOD Blood consists of cells suspended in plasma Every transport/circulatory system has 3 basic parts/components (concentrating on humans now) 1 Transport fluid: blood, in humans average amount of blood is 5 liters, blood is a liquid tissue, group of cells that work together to do a job, that general job is the transportation of stuff

15 Withdraw blood CONSTITUENT Water Salts Sodium Potassium Calcium Magnesium Chloride Bicarbonate Plasma proteins Albumin Fibrinogen Immunoglobins (antibodies) Place in tube PLASMA 55% MAJOR FUNCTIONS Solvent for carrying other substances Osmotic balance, ph buffering, and regulation of membrane permeability Osmotic balance, ph buffering Clotting Immunity Centrifuge CELL TYPE CELLULAR ELEMENTS 45% NUMBER (per mm 3 of blood) FUNCTIONS Erythrocytes (red blood cells) 5 6 million Transport of oxygen (and carbon dioxide) Leukocytes (white blood cells) 5,000 10,000 Basophil Eosinophil Defense and immunity Lymphocyte Substances transported by blood Nutrients (e.g., glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones Platelets Neutrophil 250, ,000 Monocyte Blood clotting Figure 23.13

16 Blood smear Figure 23.13x

17 Blood is made of 2 general parts: A: liquid part of the blood is called plasma, plasma is about 55% of the blood. 90% of the plasma is water other 10% contains: Nutrients (proteins, lipids, carbs, vitamins, minerals, H2O) O 2 gas (some), CO 2 gas & bicarbonate ions Metabolic wastes Blood proteins such as: Albumin (osmotic balance) Fibrinogen (clotting) Immunoglobulins (antibodies, part of immune system)

18 B: formed elements (blood cells), made in bone marrow, which is usually found in long bones, the cells in the marrow are called hemocytoblasts and have the ability to become any type of blood cell (specific type of stem cell), the formed elements include:

19 Red blood cells transport oxygen Erythrocytes (red blood cells, RBC), most numerous type of blood cell, about 5-6 million per ml (cc or cm 3 ), each RBC has no nucleus (cannot reproduce on its own), contains about 250 million molecules of hemoglobin per RBC (each molecule can carry 4 molecules of O2, have a lifespan of 120 days, recycled by liver and spleen, hemoglobin reused by bone marrow and cell fragments sent to gall bladder (become bile pigments), if not processed properly by liver develops jaundice (causes yellowing of skin and eyes) Figure 23.14

20 White blood cells help defend the body Leukocytes (white blood cells, WBCs: are about 5,000-10,000 per ml, have a nucleus, can reproduce on their own, function as a part of the immune system and help protect the body against diseases (pathogens) Basophil Eosinophil Monocyte Neutrophil Lymphocyte Figure 23.15

21 Some of the WBCs make proteins called antibodies, label foreign cells (and their antigens), other types of WBCs eat/phagocytize anything with an antibody attached. Defect in WBCs may lead to leukemia (cancer of WBCs During infection WBC count is over 10,000 per ml WBC count over 30,000 usually indicates leukemia

22 Blood clots plug leaks when blood vessels are injured Thrombocytes (platelets):, 250, ,000 per ml, not whole cells, but are cell fragments, have a lifespan of 7-10 days, main function is blood clotting Figure 23.16B

23 1 Injury to lining of blood 2 Platelet plug forms 3 vessel exposes connective tissue; platelets adhere Fibrin clot traps blood cells Connective tissue Platelet releases chemicals that make nearby platelets sticky Platelet plug Clotting factors from: Platelets Damaged cells Calcium and other factors in blood plasma Prothrombin Thrombin Fibrinogen Fibrin Figure 23.16A

24 Fig b(TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cascade of enzymatic reactions is triggered by platelets, plasma factors, and damaged tissue. Prothrombin Fibrinogen Thrombin Fibrin Threads of fibrin trap erythrocytes and form a clot. Fibrin threads

25 How does transport fluid (blood) get around? Transport tubes or vessels, what the blood moves through. In humans and other mammals there are 3 types of blood vessels.

26 Epithelium Smooth muscle Connective tissue Epithelium CAPILLARY Basement membrane Epithelium Smooth muscle Connective tissue Valve ARTERY VEIN ARTERIOLE VENULE Figure 23.5

27 Arteries: thickest, most muscular and elastic of the blood vessels, blood under high pressure, carries blood away from the heart to the body cells, carries oxygenated (oxygen rich) blood, can detect and measure blood pressure in this blood vessel.

28 Fig a(TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective tissue Smooth muscle Elastic layer Endothelial cells

29 Veins: medium thickness, carry blood back to the heart from the body cells, carries deoxygenated (oxygen poor) blood, blood is a dark red/maroon color, this blood IS NOT blue, blood APPEARS that color because of the blood vessel not the blood, blood not under high pressure, veins have valves in them to prevent backflow and keep the blood moving in one direction.

30 Fig c(TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective tissue Smooth muscle Elastic layer Endothelium

31 Three factors keep blood moving back to the heart muscle contractions breathing one-way valves Direction of blood flow in vein Valve (closed) Skeletal muscle Valve (open) Figure 23.9B

32 Artery and vein, cross-section Figure 23.5x

33 Capillaries: smallest and thinnest of the blood vessels. Also the place where the blood and body cells exchange materials, nutrients and O2 move from blood t0 body cells, metabolic wastes and CO2 move from body cells to the blood. So thin that only one RBC at a time can pass through the vessel.

34 Fig b(TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Endothelium Endothelial cells

35 The circulatory system associates intimately with all body tissues Capillaries are microscopic blood vessels They form an intricate network among the tissue cells Capillary Red blood cell Figure 23.1A

36 No substance has to diffuse far to enter or leave a cell Capillary INTERSTITIAL FLUID Diffusion of molecules Tissue cell Figure 23.1B

37 Capillaries allow the transfer of substances through their walls Figure 23.12A

38 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

39 Tissue cells Arterial end of capillary Osmotic pressure Osmotic pressure Venous end of capillary Blood pressure Blood pressure INTERSTITIAL FLUID NET PRESSURE OUT NET PRESSURE IN Figure 23.12B

40 As materials move between the blood and body cells they pass through the intercellular fluid (also called interstitial fluid or ICF), the ICF is derived from (comes from) the plasma of the blood. Not all materials that leave the blood make it to the body cells, the blood cannot continue to lose water constantly ICF gets returned to the blood slowly, but the fluid has to be filtered first

41 Our body has a separate series of tubes and vessels that filters the ICF called the lymphatic system. Once the ICF is inside the lymphatic system it is called lymph. Lymph is filtered al lymph nodes, act like pasta strainer (colander), have white blood cells called macrophages that eat/phagocytize the debris caught in the node, lymph returned to the blood vessels in the chest (thoracic duct)

42 Adenoid LYMPHATIC VESSEL Right lymphatic duct, entering vein Tonsil Lymph nodes Thoracic duct, entering vein VALVE Blood capillary Tissue cells Interstitial fluid Thoracic duct Thymus Appendix Spleen LYMPHATIC CAPILLARY Masses of lymphocytes and macrophages Bone marrow Lymphatic vessels Figure 23.3

43 This lymphatic vessel is taking up fluid from tissue spaces in the skin It will return it as lymph to the blood Lymph contains less oxygen and fewer nutrients than interstitial fluid LYMPHATIC VESSEL VALVE Blood capillary Tissue cells Interstitial fluid LYMPHATIC CAPILLARY Figure 23.3B

44 Lymph nodes are key sites for fighting infection They are packed with lymphocytes and macrophages Masses of lymphocytes and macrophages Outer capsule of lymph node Macrophages Lymphocytes Figure 23.3C, D

45 Macrophage Figure 24.1x

46 How are materials moved through the body? Heart: pump that pushes blood through the vessels, general pathway of blood through the human (vertebrate) body would be: Heart artery arteriole (small artery) capillary (exchange) venule (small vein) vein heart lungs (gas exchange) heart artery repeat many times.

47 Different organisms have different heart structures Fish have 2 chambered heart, one atrium and one ventricle

48 Fig (TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Systemic capillaries Respiratory capillaries Body Gills

49 Vertebrate cardiovascular systems reflect evolution A fish has a single circuit of blood flow Gill capillaries Heart: Ventricle (V) Atrium (A) Systemic capillaries Figure 23.3A

50 Amphibians slightly more complicated heart, 3 chambered (2 atria and 1 ventricle), some blood mixing happens in the ventricle (mixing of oxygenated and deoxygenated blood) Amphibians are unique, have a small amount of gas exchange that happens across their skin, called cutaneous respiration (gas exchange) Reptiles slightly more advanced, almost 4 chambers, has an incomplete septum (wall) between the 2 sides of the heart

51 Fig (TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. To body To body To lungs Right atrium Septum Conus arteriosus To body To body To lungs Pulmonary vein Left atrium Sinus venosus Ventricle Respiratory capillaries Systemic capillaries Lungs Body

52 Mammal heart most advanced, has 4 chambers (2 atria and 2 ventricles), has 2 completely different sides Right side: deoxygenated blood coming back to heart from body cells through a vein called the vena cave (superior & inferior), then to lungs (gas exchange) Left side: oxygenated blood comes back to heart from lungs and the left side pumps oxygenated blood out to body, more muscular side of heart, beats more forcefully (pushes blood further) Sides of heart separated by a wall called the septum

53 How does blood travel through the heart? Blood enters from: Vena cava right atrium tricuspid (AV) valve right ventricle Semilunar valve pulmonary artery lungs (gas exchange) pulmonary vein left atrium bicuspid/mitral (AV) valve left ventricle semilunar valve aorta body repeat Tricuspid and bicuspid valves prevent blood from moving back into the atria Semilunar valves: prevent blood from falling back into the ventricles

54 Pulmonary artery Aorta Superior vena cava RIGHT ATRIUM Pulmonary artery LEFT ATRIUM Pulmonary veins Pulmonary veins Semilunar valve Semilunar valve Atrioventricular valve Atrioventricular valve Inferior vena cava RIGHT VENTRICLE LEFT VENTRICLE Figure 23.4A

55 2 blood vessels are different than usual: Pulmonary artery: transports deoxygenated blood Pulmonary vein: transports oxygenated blood

56 Fig (TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superior vena cava Aortic semilunar valve Pulmonary semilunar valve Right atrium Tricuspid valve Inferior vena cava Aorta Pulmonary artery Pulmonary veins Left atrium Bicuspid mitral valve Left ventricle Right ventricle Systemic capillaries Right lung Pulmonary artery Respiratory capillaries Vena cava Head LA RA RV LV Body Systemic capillaries Left lung Pulmonary vein Aorta

57 Superior vena cava 7 Capillaries of Head and arms Pulmonary artery Pulmonary artery Capillaries of right lung 9 Aorta Capillaries of left lung Pulmonary vein RIGHT ATRIUM RIGHT VENTRICLE LEFT ATRIUM Pulmonary vein LEFT VENTRICLE Inferior vena cava Aorta 8 Capillaries of abdominal organs and legs Figure 23.4B

58 The cardiovascular system of land vertebrates has two circuits The pulmonary circuit: between heart and lungs Lung capillaries The systemic circuit: between heart and body systems. PULMONARY CIRCUIT Coronary circuit: between heart chambers and heart muscle A A Renal circuit: between heart and kidneys Hepatic portal pathway: between small intestines and liver V Right SYSTEMIC CIRCUIT V Left Systemic capillaries Figure 23.3B

59 Heart valves prevent backflow Cardiac output The amount of blood pumped into the aorta by the left ventricle per minute

60 How does the heart do its job? Heart pumps blood, heart muscle (cardiac muscle) contracts and squeezes blood out of heart through arteries. Average adult heart rate bpm (beats per minute) Heart pumps blood out through arteries once every cardiac cycle.

61 The heart contracts and relaxes rhythmically 2 phases of the cardiac cycle: Diastole Blood flows from the veins into the heart chambers while heart is relaxed Systole The atria briefly contract and fill the ventricles with blood Then the ventricles contract and propel blood out BOTH sides of heart contract together 1 Heart is relaxed. AV valves are open. DIASTOLE 0.4 sec 0.1 sec 0.3 sec 3 2 SYSTOLE Atria contract. Ventricles contract. Semilunar valves are open. Figure 23.6

62 How is the pace of the heart set? Central nervous system (CNS) sets pace of heart through medulla oblongata. Control centers in the brain adjust heart rate to body needs Sends message to sinoatrial (SA) node or pacemaker in right atrium, tells atria to beat simultaneously SA node sends message to Atrioventricular (AV) node, tells both ventricles to beat simultaneously, sends message down to tip of heart through Purkinje fibers.

63 The pacemaker sets the tempo of the heartbeat The SA node (pacemaker) generates electrical signals that trigger the contraction of the atria The AV node then relays these signals to the ventricles Pacemaker (SA node) AV node Specialized muscle fibers Right atrium Right ventricle ECG Figure 23.7

64 Can these signals be detected? Yes An electrocardiogram (ECG) is a recording of electrical changes in the skin resulting from the electrical signals in the heart P: atria contracting QRST: ventricles contracting

65 Fig (TE Art) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. SA node Internodal pathway AV node LA RA LV RV P wave in ECG ECG P Bundle of His Purkinje fibers QRS wave in ECG R 1 sec R T Q S QRS wave

66 Can also detect the squeezing the heart does on blood in the arteries in 2 ways: Pulse: detected in an artery, feel the expansion and relaxation of the artery Blood pressure, use a sphygmomanometer, or a blood pressure cuff, allows you to measure 2 things: Systolic pressure: when heart is contracting Diastolic pressure: when heart is relaxing Average adult blood pressure 120/80

67 Connection: Measuring blood pressure can reveal cardiovascular problems Blood pressure is measured as systolic and diastolic pressures Blood pressure 120 systolic 80 diastolic (to be measured) Rubber cuff inflated with air Pressure in cuff above 120 Pressure in cuff below 120 Pressure in cuff below 80 Artery Artery closed Sounds audible in stethoscope Sounds stop Figure 23.10

68 Blood exerts pressure on vessel walls Blood pressure depends on cardiac output resistance of vessels

69 Pressure is highest in the arteries It drops to zero by the time the blood reaches the veins Relative sizes and numbers of blood vessels Diastolic pressure Systolic pressure Figure 23.9A

70 Connection: What is a heart attack? A heart attack damage that occurs when a coronary artery feeding the heart is blocked Aorta Right coronary artery Left coronary artery Blockage Dead muscle tissue Figure 23.8A

71 Arteriosclerosis hardening of the arteries, build up of plaque, leads to heart attack Connective tissue Smooth muscle Epithelium Plaque Figure 23.8B

72 Athersclerosis a type of arteriosclerosis

73 Sickle cell anemia: red blood cells have a sickle shape, causes blockage in blood vessels and reduced oxygen transport, genetic

74 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

75 Stroke: blood clot in the brain Embolism: clot that is formed in one area of the body and travels to another Aneurysm: localized, blood-filled dilation (balloon-like bulge) of a blood vessel caused by disease or weakening of the vessel wall

76 Hemolytic disease of the newborn Rh disease: if a pregnant woman is known to have anti-rh antibodies the Rh blood type of a fetus can be tested by analysis of fetal Dna in the maternal plasma to assess the risk to the fetus of Rh disease. One of the major advances of 20 th century medicine was to prevent this disease by stopping the formation of Anti-Rh antibodies by Rh negative mothers with an injectable medication called Rho(d) immune globulin

77