General Information A circulatory system distributes materials throughout the vertebrate body and some invertebrates Uses a transport medium called blood A heart is a muscular organ that pumps the transport medium ID: 998511
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1. The Circulatory System
2. The Nature of Blood CirculationGeneral Information…A circulatory system distributes materials throughout the vertebrate body (and some invertebrates)Uses a transport medium called blood.A heart is a muscular organ that pumps the transport medium (blood) through vessels.Blood and interstitial fluid (fluid between cells) make up the body’s internal environment
3. There are 2 Kinds of Circulatory SystemsWell actually 3 if you consider that Poriferans, like sponges, exchange gases directly with the environment.OpenOr Closed
4. Direct Circulation: Diffussion.
5. Fig. 37-2a, p. 638pumpaortaheartspaces or cavities in body tissuesA In a grasshopper’s open system, a heart (not like yours) pumps blood through a vessel, a type of aorta. From there, blood moves into tissue spaces, mingles with interstitial fluid, then reenters the heart at openings in the heart wall.Open Circulatory SystemsOpen circulatory system (of arthropods or mollusks)Blood moves through hearts and large vessels, but also mixes with interstitial fluid
6. Fig. 37-2b, p. 638dorsal blood vesselpumplarge-diameter blood vesselslarge-diameter blood vesselstwo of five heartsventral blood vesselsgut cavitycapillary bed (many small vessels that serve as a diffusion zone)B The closed system of an earthworm confines blood inside pairs of muscular hearts near the head end and inside many blood vessels.Closed Circulatory SystemsClosed circulatory system (of annelids (worms) and all vertebrates)Blood remains inside heart and blood vessels Molecules (CO2 & O2) diffuse between blood and interstitial fluid at capillaries
7. Evolution of Circulation in VertebratesFishesHeart with two chambersSingle circuit of circulationAmphibiansHeart with three chambersTwo partially separated circuitsBirds and mammalsHeart with four chambersTwo fully separate circuits
8. Fig. 37-3a, p. 639A In fishes, the heart has two chambers: one atrium and one ventricle. Blood flows through one circuit. It picks up oxygen in the capillary beds of the gills, and delivers it to capillary beds in all body tissues. Oxygen-poor blood then returns to the heart.capillary beds of gillsheartrest of bodySingle Circuit of Circulation
9. Fig. 37-3b, p. 639lungsB In amphibians, the heart has three chambers: two atria and one ventricle. Blood flows along two partially separated circuits. The force of one contraction pumps blood from the heart to the lungs and back. The force of a second contraction pumps blood from the heart to all body tissues and back to the heart.right atriumleft atriumventriclerest of bodyTwo Partially Separate Circuits of Circulation
10. Circulation in Birds and Mammals The four-chambered heart has two separate halves, each with an atrium and a ventricleEach half pumps blood in a separate circuitPulmonary circuit: Blood flows from right half of heart, to lungs (gains oxygen), to left half of heart Systemic circuit: Blood flows from left half of heart, to body (loses oxygen), to right half of heart
11. Fig. 37-3c, p. 639C In birds and mammals, the heart has four chambers: two atria and two ventricles. The blood flows through two fully separated circuits. In one circuit, blood flows from the heart to the lungs and back. In the second circuit, blood flows from the heart to all body tissues and back.lungsright atriumleft atriumright ventricleleft ventriclerest of bodyTwo Fully Separate Circuits of Circulation
12. Fig. 37-3d, p. 639D Why flow slows in capillaries. Picture a volume of water in two fast rivers flowing into and out of a lake. The flow rate is constant, with an identical volume moving from points 1 to 3 in the same interval. However, flow velocity decreases in the lake. Why? The volume spreads out through a larger cross-sectional area and flows forward a shorter distance during the specified interval.This extra time allows for diffusion of gases, like oxygen into cells and carbon dioxide out of cells, as well as nutrients like sugars, fats, and proteins. lakeriver inriver out123123123Analogy of Slowing Blood in Capillaries
13. Overview of Circulatory SystemsFill in the blank.Many animals have either an ________ or a ________ circulatory system that transports substances to and from all body tissues.Some organisms have neither, achieving basic circulation by __________, which is the direct exchange of important biomolecules with the environment. All vertebrates have a _______ circulatory system, in which blood is _______________________________.
14. Overview of Circulatory SystemsMany animals have either an open or a closed circulatory system that transports substances to and from all body tissues Some organisms have neither, achieving basic circulation by diffusion, which is the direct exchange of important biomolecules with the environment. All vertebrates have a closed circulatory system, in which blood is always contained within the heart or blood vessels
15. Characteristics of BloodBlood, considering it is made of cells, can be called a large interconnect tissue.
16. Blood CellsBlood consists mainly of plasma, a protein-rich fluid that carries wastes, gases and nutrients.Blood cells and platelets form in bone marrow and are transported in plasma.Platelets are fragments of megakaryocytes, active in clotting.Red blood cells (erythrocytes)Contain hemoglobin that carries oxygen from lungs to tissuesQuantified in cell countWhite blood cells (leukocytes)Defend the body from pathogensNeutrophils, basophils, eosinophils, monocytes, and lymphocytes (B and T cells)
17. Fig. 37-4, p. 640Stepped ArtComponentsAmountsMain FunctionsPlasma Portion (50-60% of total blood volume)Cellular Portion (40-50% of total blood volume; numbers per microliter)1. Water91-92% of totalplasma volumeSolvent2. Plasma proteins (albumins, globulins, fibrinogen, etc.7-8%Defense, clotting, lipid transport, extracellular fluid volume controls3. Ions, sugars, lipids, amino acids, hormones, vitamins, dissolved gases, etc.1-2%Nutrition, defense, respiration, extracellular fluid volume controls, cell communication, etc. 1. Red blood cellsRed blood cell4,600,000-5,400,000Oxygen, carbon dioxide transport to and from lungs2. White blood cells: Neutophils Lymphoctyes Monocytes (macrophages) Eosinophils BasophilsWhite blood cell3,000-6,7501,000-2,700150-720100-38025-90Fast-acting phagocytosisImmune responsesPhagocytosisKilling parasitic wormsAnti-inflammatory secretions3. Plateletsplatelet250,000-300,000Roles in blood clottingComponents of Human Blood
18. Fig. 37-5, p. 641stem cell in bone marrowmyeloid stem celllymphoid stem cellred blood cellgranulocytemonocyteprecursorprecursorprecursormegakaryocytesplateletsred blood cells (erythrocytes)neutrophilseosinophilsbasophilsmonocytes (immature phagocytes)B lymphocytes (mature in bone marrow)T lymphocytes (mature in thymus)Cellular Components of Human Blood
19. HemostasisHemostasis = Heme (blood) stasis (balance)Keeping blood pressure/volume stable.How do we stop bleeding?Initiated by a hormone cascade when an injury is sustained and blood vessels are broken.Hemostasis is a three-phase process that stops blood loss, constructs a framework for repairsDamaged vessel constrictsPlatelets accumulateCascading enzyme reactions involving plasma proteins cause clot formation
20. Fig. 37-6, p. 642Stepped ArtStimulusA blood vessel is damaged.Phase 1 responseA vascular spasm constricts the vessel.Phase 2 responsePlatelets stick together plugging the site.Phase 3 responseClot formation starts:2. Factor X converts prothrombin in plasma to thrombin3. Thrombin converts fibrinogen, a plasma protein, to fibrin threads.4. Fibrin forms a net that entangles cells and platelets, forming a clot.1. Enzyme cascade results in activation of Factor X.Three-Phase Process of Hemostasis
21. Blood TypingBlood typeGenetically determined differences in molecules on the surface of red blood cells
22. AgglutinationLight micrographs showing (a) an absence of agglutination in a mixture of two different yet compatible blood types and (b) agglutination in a mixture of incompatible types.AgglutinationClumping of foreign cells by plasma proteinsWhen blood of incompatible types mixes, the immune system attacks the unfamiliar molecules
23. ABO Blood TypingBlood type O is a universal donor; blood type AB can receive blood from any donor
24. Fig. 37-8, p. 643Blood Type of DonorOABABOABBlood Type of RecipientABMixing ABO Blood Types
25. Rh Blood TypingAn Rh- mother may develop Rh+ antibodies if blood from an Rh+ child enters her bloodstream during childbirthThese antibodies may attack the red blood cells of the next Rh+ fetus
26. Rh Complications of PregnancyHow Rh differences can complicate pregnancy.
27. Blood Composition and FunctionFill in the blanks.Vertebrate blood is a fluid connective ________. It consists of _______, ________, ________, and _________ (the transport medium) _____ _______ cells function in gas exchange; _____ _______ cells defend tissues, and _________ function in clotting
28. Blood Composition and FunctionVertebrate blood is a fluid connective tissue It consists of red blood cells, white blood cells, platelets, and plasma (the transport medium) Red blood cells function in gas exchange; white blood cells defend tissues, and platelets function in clotting
29. Human Cardiovascular SystemThe term “cardiovascular” comes from the Greek kardia (for heart) and Latin vasculum (vessel)In a cardiovascular circuit, blood flows from the heart through arteries, arterioles, capillaries, venules, veins, and back to the heart.
30. Two Circuits of the Human Cardiovascular SystemPulmonary circuitOxygen-poor blood flows from the heart, through a pair of lungs, then back to the heartBlood takes up oxygen in the lungsSystemic circuitOxygenated blood flows from the heart (through the aorta) into capillary beds where it gives up O2 and takes up CO2, then flows back to the heart
31. Fig. 37-10a, p. 644right pulmonary arteryleft pulmonary arterycapillary bed of right lungcapillary bed of left lungpulmonary trunkto systemic circuitfrom systemic circuitpulmonary veinsheartPulmonary Circuit of the Human Cardiovascular SystemAccessing the lungs to rid blood stream of excess CO2 & to replenish O2Blood vessels carrying oxygenated blood are shown in red. Those that hold oxygen-poor blood are color-coded blue.
32. capillary beds of head, upper extremities(pulmonary vessels to and from thoracic cavity)to pulmonary circuitaortafrom pulmonary circuitheartcapillary beds of other organs in thoracic cavity(diaphragm, the muscular partition between thoracic and abdominal cavities)capillary bed of livercapillary beds of intestinesBSystemic Circuit for Blood Flowcapillary beds of other abdominal organs and lower extremitiesSystemic Circuit of the Human Cardiovascular SystemPulmonary and systemic circuits of the human cardiovascular system. Blood vessels carrying oxygenated blood are shown in red. Those that hold oxygen-poor blood are color-coded blue.Accessing the rest of the body to deliver O2& to retrieve CO2
33. The Pulmonary CircuitDoes?The Systemic CircuitDoes?Deoxygenated blood brought to the lungs to replenish O2Oxygenated blood sent to heart to distribute O2 throughout bodyBlue = deoxygenatedRed = oxygenated
34. Fig. 37-12, p. 645food, water intakeoxygen intakeDigestive SystemRespiratory Systemelimination of carbon dioxidenutrients, water, saltsoxygencarbon dioxideCirculatory SystemUrinary Systemwater, soluteselimination of food residuesrapid transport to and from all living cellselimination of excess water, salts, wastesThe Circulatory System and HomeostasisFunctional links between the circulatory system and other organ systems with major roles in maintaining the internal environment.
35. The Human HeartA sac of connective tissue (pericardium) surrounds the heart muscle (myocardium)Endothelium lines heart chambers and blood vesselsHeart valves keep blood moving in one directionAV valves separate atria and ventriclesSemilunar valves separate ventricles and arteries
36. Fig. 37-13b, p. 646right lungleft lungribs 1–8B The heart is located between the lungs in the thoracic cavity.13245678pericardiumdiaphragmThe Human Heart
37. Fig. 37-13a, p. 646superior vena cava (flow from head, arms)arch of aortatrunk of pulmonary arteries (to lungs)right semilunar valve (shown closed) to pulmonary trunkleft semilunar valve (closed) to aortaright pulmonary veins (from lungs)left pulmonary veins (from lungs)right atriumleft atriumright AV valve (opened) = TRICUSPID VALVEleft AV valve (opened) = MITRAL VAVLEright ventricleleft ventricle(muscles that prevent valve from everting)endothelium and underlying connective tissueinferior vena cava (from trunk, legs)myocardiumseptum (partition between heart’s two halves)inner layer of pericardiumheart’s apexThe Human Heart
38. Fig. 37-13c, p. 646C Outer appearance. Pads of fat on the heart’s surface are normal.The Human Heart
39. The Cardiac CycleCardiac cycle: Heart muscle alternates between diastole (relaxation) and systole (contraction)Blood collects in atriaAV valves open, blood flows into ventriclesContraction of ventricles drives blood circulationVentricles contract with a wringing motion from bottom to top
40. Fig. 37-14, p. 647D Ventricles relax. Semilunar valves close as atria begin filling for the next cardiac cycle.A Atria fill. Fluid pressure opens the AV valves, blood flows into the ventricles.B Next, atria contract. As fluid pressure rises in the ventricles, AV valves close.C Ventricles contract. Semilunar valves open. Blood flows into aorta and pulmonary artery.Stepped ArtThe Cardiac Cycle
41. Cardiac MuscleCardiac muscle cells are striated (divided into sarcomeres) and have many mitochondriaCells attach end to end at intercalated discsNeighboring cells communicate through gap junctions that conduct waves of excitation
42. Fig. 37-15, p. 647intercalated diska branching cardiac muscle cell (part of one cardiac muscle fiber)b Part of a gap junction across the plasma membrane of a cardiac muscle cell. The junctions connect cytoplasm of adjoining cells and allow electrical signals that stimulate contraction to spread swiftly between them.Cardiac Muscle Cells and Gap Junctions
43. How the Heart BeatsCardiac pacemaker (SA node)A clump of noncontracting cells in the right atrium’s wall spontaneously fires action potentials about 70 times per minuteCardiac conduction systemSignal spreads from SA node to AV node and junctional fibers in the septum, so heart contracts in a coordinated fashion
44. Fig. 37-16, p. 647SA node (cardiac pacemaker)AV node (the only point of electrical contact between atria and ventricles)junctional fibersbranchings of junctional fibers (carry electrical signals through the ventricles)The Cardiac Conduction System
45. The Human Heart and Two Flow CircuitsFill in the blanksThe ______-chambered human heart pumps blood through _____ separate circuits of blood vessels One circuit extends through _____________, the other through _______ tissue only. Both circuits loop back to the __________, which keeps blood flowing through the _______ circuits.
46. The Human Heart and Two Flow CircuitsThe four-chambered human heart pumps blood through two separate circuits of blood vessels One circuit extends through all body regions, the other through lung tissue only. Both circuits loop back to the heart, which keeps blood flowing through the two circuits.
47. Part IIPressure, Transport, and Flow Distribution
48. Fig. 37-11, p. 645Jugular VeinsCarotid Arteries Ascending Aorta Superior Vena CavaPulmonary Arteries Pulmonary VeinsCoronary ArteriesHepatic Vein Brachial ArteryRenal Vein Renal ArteryInferior Vena CavaAbdominal Aorta Iliac VeinsIliac Arteries Femoral ArteryFemoral VeinMajor Blood Vessels of the Human Cardiovascular System
49. Pressure, Transport, and Flow DistributionContracting ventricles put pressure on the blood, forcing it through a series of vesselsArteries carry blood from ventricles to arteriolesArterioles control blood distribution to capillariesCapillaries exchange substancesVenules collect blood from capillariesVeins deliver blood back to heart
50. Fig. 37-17a, p. 648outer coatsmooth musclebasement membraneendotheliumArteryelastic tissueelastic tissueHuman Blood Vessels
51. Fig. 37-17b, p. 648outer coatsmooth muscle rings over elastic tissuebasement membraneendotheliumArterioleHuman Blood Vessels
52. Fig. 37-17c, p. 648basement membraneendotheliumCapillary(venules have a similar structure)Human Blood Vessels
53. Fig. 37-17d, p. 648outer coatsmooth muscle, elastic fibersbasement membraneendotheliumVeinvalveHuman Blood Vessels
54. Blood PressureBlood pressureThe pressure exerted by blood on the walls of blood vesselsHighest in arteries, then declines through circuitRate of blood flow depends on the difference in blood pressure between two points, and resistance to flow
55. Fig. 37-18, p. 648arteriescapillariesveinsarteriolesvenulesBlood Pressure in the Systolic Circuit: Plot of fluid pressure for a volume of blood as it flows through the systemic circuit. Systolic pressure occurs when ventricles contract, diastolic when ventricles are relaxed.
56. Blood FlowThick, elastic arteries smooth out variations in blood pressure during the cardiac cycleArterioles respond to signals from the autonomic and nervous systems, and to chemical signals, to direct blood flow to different parts of the body
57. Fig. 37-19, p. 649liver6%heart’s right halfheart’s left halflungs100%skeletal musclebrain13%15%kidneys20%digestive tract21%cardiac muscle3%bone5%skin9%all other regions8%Distribution of Cardiac Output in a Resting PersonFigure It Out: What percentage of the brain’s blood supply arrives from the heart’s right half? Answer: None
58. Controlling Blood PressureBlood pressure depends on total blood volume, how much blood the ventricles pump (cardiac output), and whether arterioles are constricted or dilatedReceptors in the aorta and carotid arteries monitor blood pressure and send signals to the medulla, which regulates cardiac output and arteriole diameter
59. Measuring Blood Pressure
60. Diffusion at Capillaries, Then Back to the HeartCapillaryA cylinder of endothelial cells, one cell thickCapillary beds are diffusion zones, where blood exchanges substances with interstitial fluidHydrostatic pressure moves materials out (ultrafiltration)Osmotic pressure moves water in (capillary reabsorption)
61. blood to venulehigh pressure causes outward flowinward-directed osmotic movementcells of tissueBblood from arterioleAFluid Movement at a Capillary BedFluid movement at a capillary bed. Fluid crosses a capillary wall by way of ultrafiltration and reabsorption. (a) At the capillary’s arteriole end, a difference between blood pressure and interstitial fluid pressure forces out plasma, but few plasma proteins, through clefts between endothelial cells of the capillary wall. Ultrafiltration is the outward flow of fluid across the capillary wall as a result of hydrostatic pressure. (b) Reabsorption is the osmotic movement of some interstitial fluid into the capillary. It happens when the water concentration between interstitial fluid and the plasma differs. Plasma, with its dissolved proteins, has a greater solute concentration and therefore a lower water concentration. Reabsorption near the end of a capillary bed tends to balance ultrafiltration at the start of it. Normally, there is only a small net filtration of fluid, which vessels of the lymphatic system return to blood (Section 37.10).
62. Venous PressureVenules deliver blood from capillaries to veinsVeins deliver blood to the heartLarge-diameter, blood volume reservoirsValves help prevent backflowAmount of blood in veins varies with activity level
63. Fig. 37-22a, p. 651venous valveVenous Valve ActionVenous valve action. (a) Valves in medium-sized veins prevent the backflow of blood. Adjacent skeletal muscles helps raise fluid pressure inside a vein. (b) These muscles bulge into a vein as they contract. Pressure inside the vein rises and helps keeps blood flowing forward. (c) When muscles relax, the pressure that they exerted on the vein is lifted. Venous valves shut and cut off backflow.
64. blood flow to heartvalve openvalve closedvalve closedvalve closed
65. Key Concepts Blood Vessel Structure and FunctionThe heart pumps blood rhythmically, on its own Adjustments at arterioles regulate how blood volume is distributed among tissues Exchange of gases, wastes, and nutrients between the blood and tissues takes place at capillaries
66. Blood and Cardiovascular DisordersRed blood cell disordersAnemias, beta-thalassemias, polycythemiaWhite blood cell disordersInfectious mononucleosis, leukemias, lymphomasClotting disordersHemophilia, thrombus, embolus
67. Blood and Cardiovascular DisordersAtherosclerosisBuildup of lipids in the arterial wall that narrows the lumen, may rupture and trigger heart attack
68. Fig. 37-23a, p. 652wall of artery, cross-sectionunobstructed lumen of a normal artery
69. Fig. 37-23b, p. 652atherosclerotic plaqueblood clot sticking to plaquenarrowed lumen
70. Clogged Coronary Arteries
71. Fig. 37-24a, p. 653coronary arteryThe photo shows coronary arteries and other blood vessels that service the heart. Resins were injected into them. Then the cardiac tissues were dissolved to make an accurate, three-dimensional corrosion cast.
72. Fig. 37-24b, p. 653aortacoronary artery blockagelocation of a shunt made of a section taken from one of the patient’s other blood vesselsThe sketch shows two coronary bypasses (color-coded green), which extend from the aorta past two clogged parts of the coronary arteries.
73. Blood and Cardiovascular DisordersHypertension – a silent killerChronic blood pressure above 140/90High blood pressure and atherosclerosis increase the risk of heart attack and stroke
74. Fig. 37-25, p. 653one normal heartbeat00.2 0.4 0.6 0.8a time (seconds)bradycardia (here, 46 beats per minute)tachycardia (here, 136 beats per minute)bcventricular fibrillationdBlood and Cardiovascular DisordersArrhythmias – abnormal heart rhythmsEKGs record electrical activity of cardiac cycle
75. Risk FactorsCardiovascular disorders are the leading cause of death in the United StatesRisk factorsTobacco smoking, family history, hypertension, high cholesterol, diabetes mellitus, obesity, age, physical inactivity, gender
76. Key Concepts When the System Breaks DownCardiovascular problems include clogged blood vessels or abnormal heart rhythms Some problems have a genetic basis; most are related to age or life-style