4 Blood always stays in a blood vessel - more efficient Blood empties into sinus
5 Arteries carry blood to capillaries The sites of chemical exchange between the blood and interstitial fluidVeinsReturn blood from capillaries to the heart
6 Completely separation ensures oxygenated blood going to systemic circuit under high pressure The pulmonary and systemic circuits are not completely separatedBlood going through body under low pressure
30 The osmotic pressure due to the proteins in the blood plasma allow for about 85% of the fluids to reenter the capillaries - the remaining 15% that remain in the interstitual fluid returns via the lymph system
31 Arterial end of capillary The difference between blood pressure and osmotic pressureDrives fluids out of capillaries at the arteriole end and into capillaries at the venule endAt the arterial end of acapillary, blood pressure isgreater than osmotic pressure,and fluid flows out of thecapillary into the interstitial fluid.CapillaryRedbloodcell15 mTissue cellINTERSTITIAL FLUIDNet fluidmovement outmovement inDirection ofblood flowBlood pressureOsmotic pressureInward flowOutward flowPressureArterial end of capillaryVenule endAt the venule end of a capillary, blood pressure is less than osmotic pressure, and fluid flows from the interstitial fluid into the capillary.Figure 42.14
32 If the hydrostatic pressure increases there is an increases OUTFLOW of fluids into the cells
33 If hydrostatic pressure decreases there will be an Net INFLOW of material from the cells
34 Decreasing the plasma proteins lowers the osmotic pressure of the blood causing more fluid to be pushed outward
35 8. The lymphatic system returns fluid to the blood and aids in body defense Fluids and some blood proteins that leak from the capillaries into the interstitial fluid are returned to the blood via the lymphatic system.Fluid enters this system by diffusing into tiny lymph capillaries intermingled among capillaries of the cardiovascular system.Once inside the lymphatic system, the fluid is called lymph, with a composition similar to the interstitial fluid.The lymphatic system drains into the circulatory system near the junction of the venae cavae with the right atrium.
43 Found in bone marrow - ribs, vertebrae, breastbone, pelvis Low O2 triggers erythropoeitin
44 At high altitudes more red blood cells are produced Preadapted for high altitudes
45 each level results in many more molecules Ex: thromboplastinCascade effect: each step as as an enzyme catalyzing many more reactions at each step -each level results in many more molecules
46 LDL may increase plaque deposits - HDL may decrease A blood clot or thrombus can result in a thromboembolusin the brain it could result in a strokein the heart it could result in a myocardial infarction or heart attackFatty deposits result in Atherosclerosis -more likely to catch thrombusLDL may increase plaque deposits - HDL may decrease
48 To some extent, the tendency to develop hypertension and atherosclerosis is inherited. Nongenetic factors include smoking, lack of exercise, a diet rich in animal fat, and abnormally high levels of cholesterol in the blood.One measure of an individual’s cardiovascular health or risk of arterial plaques can be gauged by the ratio of low-density lipoproteins (LDLs) to high-density lipoproteins (HDLs) in the blood.LDL is associated with depositing of cholesterol in arterial plaques.HDL may reduce cholesterol deposition.
49 4 Basic Needs of Gas Exchange 1. A thin, moist respiratory surface of adequate dimension2. A method of transport of gases to the inner cells3. A means of protecting the fragile respiratory surface4. A way to keep the surface moist while limiting water lossGas exchange is needed for cell respiration
53 In some invertebratesThe gills have a simple shape and are distributed over much of the body(a) Sea star. The gills of a sea star are simple tubular projections of the skin. The hollow core of each gill is an extension of the coelom (body cavity). Gas exchange occurs by diffusion across the gill surfaces, and fluid in the coelom circulates in and out of the gills, aiding gas transport. The surfaces of a sea star’s tube feet also function in gas exchange.GillsTube footCoelomFigure 42.20a
54 Many segmented worms have flaplike gills That extend from each segment of their bodyFigure 42.20b(b) Marine worm. Many polychaetes (marine worms of the phylum Annelida) have a pair of flattened appendages called parapodia on each body segment. The parapodia serve as gills and also function in crawling and swimming.ParapodiaGill
55 The gills of clams, crayfish, and many other animals Are restricted to a local body regionFigure 42.20c, d(d) Crayfish. Crayfish and other crustaceans have long, feathery gills covered by the exoskeleton. Specialized body appendages drive water over the gill surfaces.(c) Scallop. The gills of a scallop are long,flattened plates that project from themain body mass inside the hard shell.Cilia on the gills circulate water around the gill surfaces.Gills
63 The tracheal tubes Supply O2 directly to body cells Figure 42.22b Air sacBody cellTracheaTracheoleTracheolesMitochondriaMyofibrilsBody wall(b) This micrograph shows cross sections of tracheoles in a tiny piece of insect flight muscle (TEM). Each of the numerous mitochondria in the muscle cells lies within about 5 µm of a tracheole.Figure 42.22b2.5 µmAir
64 Unlike branching tracheal systems, lungs are restricted to one location. Because the respiratory surface of the lung is not in direct contact with all other parts of the body, the circulatory system transports gases between the lungs and the rest of the body.Lungs have a dense net of capillaries just under the epithelium that forms the respiratory surface.Lungs have evolved in spiders, terrestrial snails, and vertebrates.
65 Book lung found in spiders subdivisions increase surface area
66 Increasing the subdivision of the lungs increases the surface area for gas exchange
67 Mammalian Respiratory Systems: A Closer Look A system of branching ductsConveys air to the lungsBranch from the pulmonary vein (oxygen-rich blood)Terminal bronchioleBranch from the pulmonary artery (oxygen-poor blood)AlveoliColorized SEMSEM50 µmHeartLeft lungNasal cavityPharynxLarynxDiaphragmBronchioleBronchusRight lungTracheaEsophagusFigure 42.23
69 How an Amphibian Breathes An amphibian such as a frogVentilates its lungs by positive pressure breathing, which forces air down the trachea
70 How a Mammal Breathes Mammals ventilate their lungs By negative pressure breathing, which pulls air into the lungsAir inhaledAir exhaledINHALATION Diaphragm contracts (moves down)EXHALATION Diaphragm relaxes (moves up)DiaphragmLungRib cage expands as rib muscles contractRib cage gets smaller as rib muscles relaxFigure 42.24
71 Higher air pressure forces air in Lower pressureTidal volume is a normal breathVital capacity is the max volume of a breathResidual volume is left over after exhalation- old air that will be mixed in with the newNegative pressure breathingThe volume increases by the diaphragm moving down and the rib cage moving up and out
73 How a Bird Breathes Besides lungs, bird have eight or nine air sacs That function as bellows that keep air flowing through the lungsINHALATION Air sacs fillEXHALATION Air sacs empty; lungs fillAnterior air sacsTracheaLungsPosterior air sacsAir1 mmAir tubes (parabronchi) in lungFigure 42.25Parabronchi allow for one way flow of air through lungs
75 High CO2 levels increase the acidity of blood and cerebrospinal fluid triggering the medulla to increase the depth and rate of breathingLow O2 levels trigger sensors in the Carotid arteries and the Aorta to trigger the medulla
76 Our breathing control centers are located in two brain regions, the medulla oblongata and the pons. Aided by the control center in the pons, the medulla’s center sets basic breathing rhythm, triggering contraction of the diaphragm and rib muscles.A negative-feedback mechanism via stretch receptors prevents our lungs from overexpanding by inhibiting the breathing center in the medulla.
77 Concept 42.7: Respiratory pigments bind and transport gases The metabolic demands of many organismsRequire that the blood transport large quantities of O2 and CO2
78 The Role of Partial Pressure Gradients Gases diffuse down pressure gradientsIn the lungs and other organsDiffusion of a gasDepends on differences in a quantity called partial pressure
80 Oxygen Transport The respiratory pigment of almost all vertebrates Is the protein hemoglobin, contained in the erythrocytes
81 Like all respiratory pigments Hemoglobin must reversibly bind O2, loading O2 in the lungs and unloading it in other parts of the bodyOne molecule of hemoglobin has 4 prosthetic heme groups, allowing it to bind to 4 O2 moleculesCooperativity-the binding of one O2 allows the next O2 to bind easierHeme groupIron atomO2 loadedin lungsO2 unloadedIn tissuesPolypeptide chainO2Figure 42.28
82 Loading and unloading of O2 Depend on cooperation between the subunits of the hemoglobin moleculeThe binding of O2 to one subunit induces the other subunits to bind O2 with more affinity
83 Cooperative O2 binding and release Is evident in the dissociation curve for hemoglobinA drop in pHLowers the affinity of hemoglobin for O2
84 Bohr shifts curve to the right H+ from carbonic acid can act as a negative modulator for hemoglobin, causing it to release more O2Bohr shifts curve to the rightAt 40 mm HGpH 7.2= 60 mm HgpH 7.4= 70 mm Hg
85 As with all proteins, hemoglobin’s conformation is sensitive to a variety of factors. For example, a drop in pH lowers the affinity of hemo- globin for O2, an effect called the Bohr shift.Because CO2 reacts with water to form carbonic acid, an active tissue will lower the pH of its surroundings and induce hemoglobin to release more oxygen.Fig b
92 Bet You Didn't Know They Treat Meat With Carbon Monoxide To Fool You Bet You Didn't Know They Treat Meat With Carbon Monoxide To Fool You. Hemoglobin has a great affinity to CO – it binds and turns red, giving even old meat the appearance of freshness.If you breath in CO, hemoglobin will not release it and not be able to transport O2.
93 Figure 42.30Tissue cellCO2Interstitial fluidCO2 producedCO2 transport from tissuesBlood plasma within capillaryCapillary wallH2ORed blood cellHbCarbonic acidH2CO3HCO3–H++BicarbonateHemoglobin picks up CO2 and H+Hemoglobin releases CO2 and H+CO2 transport to lungsAlveolar space in lung2134567891011To lungsCarbon dioxide produced by body tissues diffuses into the interstitial fluid and the plasma.Over 90% of the CO2 diffuses into red blood cells, leaving only 7% in the plasma as dissolved CO2.Some CO2 is picked up and transported by hemoglobin.However, most CO2 reacts with water in red blood cells, forming carbonic acid (H2CO3), a reaction catalyzed by carbonic anhydrase contained. Within red blood cells.Carbonic acid dissociates into a biocarbonate ion (HCO3–) and a hydrogen ion (H+).Hemoglobin binds most of the H+ from H2CO3 preventing the H+ from acidifying the blood and thus preventing the Bohr shift.CO2 diffuses into the alveolar space, from which it is expelled during exhalation. The reduction of CO2 concentration in the plasma drives the breakdown of H2CO3Into CO2 and water in the red blood cells (see step 9), a reversal of the reaction that occurs in the tissues (see step 4).Most of the HCO3– diffuse into the plasma where it is carried in the bloodstream to the lungs.In the HCO3– diffuse from the plasma red blood cells, combining with H+ released from hemoglobin and forming H2CO3.Carbonic acid is converted back into CO2 and water.CO2 formed from H2CO3 is unloaded from hemoglobin and diffuses into the interstitial fluid.
94 Deep-diving air-breathers stockpile oxygen and deplete it slowly When an air-breathing animal swims underwater, it lacks access to the normal respiratory medium.Most humans can only hold their breath for 2 to 3 minutes and swim to depths of 20 m or so. In comparison with diving mammals, humans are poorly adapted to life in the water. In 2002, free-diving champion Mandy-Rae Cruikshank set a women’s world record for static apnea of 6 minutes 13 seconds (the men’s record, set in 2001 by Scott Campbell, is 6 minutes 45 seconds)However, a variety of seals, sea turtles, and whales can stay submerged for much longer times and reach much greater depths.
95 Weddell Seal Dive Adaptations Stores more O2 in its bloodHas more blood, has larger spleen for storage of bloodHas higher amount of O2 storing protein called myoglobin in musclesHeart rate(125>10) and O2 consumption rate decreaseBlood to muscles restrictedBlood routed to vital organs -brain, eyes /peripheral vasoconstriction.
96 A school of salema attempts to outmaneuver a hungry sea lion near the Galápagos Islands by circling to confuse the predator. Galápagos sea lions dive down some 120 feet (37 meters) on average to feed, returning to the surface after a minute or two to breathe.
97 The medulla’s control center monitors the CO2 level of the blood and regulated breathing activity appropriately.Its main cues about CO2 concentration come from slight changes in the pH of the blood and cerebrospinal fluid bathing the brain.Carbon dioxide reacts with water to form carbonic acid, which lowers the pH.When the control center registers a slight drop in pH, it increases the depth and rate of breathing, and the excess CO2 is eliminated in exhaled air.
98 The breathing center responds to a variety of nervous and chemical signals and adjusts the rate and depth of breathing to meet the changing demands of the body.However, breathing control is only effective if it is coordinated with control of the circulatory system, so that there is a good match between lung ventilation and the amount of blood flowing through alveolar capillaries.For example, during exercise, cardiac output is matched to the increased breathing rate, which enhances O2 uptake and CO2 removal as blood flows through the lungs.
104 Cooperative oxygen binding and release is evident in the dissociation curve for hemoglobin. Where the dissociation curve has a steep slope, even a slight change in PO2 causes hemoglobin to load or unload a substantial amount of O2.This steep part corresponds to the range of partial pressures found in body tissues.Hemoglobin can release an O2 reserve to tissues with high metabolism.Fig a
105 In addition to oxygen transport, hemoglobin also helps transport carbon dioxide and assists in buffering blood pH.About 7% of the CO2 released by respiring cells is transported in solution.Another 23% binds to amino groups of hemoglobin.About 70% is transported as bicarbonate ions.