BIOH 370 1st EditionLecture 20 Outline of Last Lecture Respiratory SystemI. Respirationa. Structurallyb. FunctionallyII. Sinus Abnormalities III. Pharynx and LarnyxIV. Conducting Zone StructuresV. Respiratory Zone StructuresVI. Respiratory MembraneVII. Pleurae- PleurisyVIII. Mechanics of BreathingIX. Pressure Changes in Pulmonary VentilationX. Atelectasis Outline of Current Lecture Respiratory System Day 2I. Factors that Affect Pulmonary Ventilationa. Surface TensionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.b. Elastic Recoilc. ComplianceII. Alveolar Surface TensionIII. Lung ComplianceIV. Spirogram of Lung volumes and CapacitiesV. Dalton’s Law of Partial PressuresVI. Henry’s LawVII. External vs Internal RespirationVIII. Transport of O2 and CO2 in the BloodIX. HemoglobinX. O2 and CO2 Transport during External and Internal Respirationa. Haldane EffectXI. Medullary Rhythmicity AreaXII. Control of RespirationXIII. Respiratory Adjustmentsa. Exerciseb. High AltitudeXIV. Homeostatic Imbalances of the Respiratory Systema. COPDb. Asthmac. Tuberculosisd. Lung CancerXV. Respiratory System Developmental AspectsCurrent LectureRespiratory System Day 2I. Factors that Affect Pulmonary Ventilation(need all 3 of these) Surface Tension: Inwardly directed force in the alveoli which must be overcome to expand the lungs during each inspiration Elastic Recoil: Decreases the size of the alveoli during expiration- when you exhale Compliance: Ease with which the lungs and thoracic wall can be expanded- due to lung tissue itself and thoracic cavityII. Alveolar Surface Tension:o Surface tension Attracts liquid molecules to one another at a gas-liquid interface  Resists any force that tends to increase the surface area of the liquido Surfactant Detergent-like lipid and protein complex produced by type II alveolar cells Reduces surface tension of alveolar fluid and discourages alveolar collapse Insufficient quantity in premature infants causes infant respiratory distress syndromeo By 28 weeks, most premature babies can breathe on their owno Steroids help the lungs mature: usually betamethasone or dexamethasoneo Increases surfactant productiono Decreases amount of fluid in neonatal lungso Increases lung volume (so more air exchange)o Helps babies respond to surfactant therapyIII. Lung Compliance: A measure of the change in lung volume that occurs with a given change in transpulmonary pressureo Normally high in non-diseased lungs due to Distensibility of the lung tissue  Alveolar surface tensiono Diminished in CF patients by Nonelastic scar tissue (fibrosis)  Reduced production of surfactant Decreased flexibility of the thoracic cageo Cystic Fibrosis: genetic mutation due to cilia formation mutation= chronic lung disease Treatments=pounded method to clean out mucus because cilia does not work properly so body can’t get rid of mucus on ownIV. Spirogram of Lung volumes and Capacities Alveolar ventilation rate (AVR): flow of gases into and out of the alveoli during a particular time Dead space is normally constant Rapid, shallow breathing decreases AVRV. Dalton’s Law of Partial Pressures: Each gas in a mixture of gases exerts its own pressure as if no other gases were present Atmospheric pressure= PN2+ P02+Par+PH20+PCO2+Pother gasesVI. Henry’s Law: : The quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility coefficient when the temperature remains constant means that more CO2 is in the alveoli because of the percentage of water vapor in the alveoli is higher than atmospheric pressureCO2 exhaledO2 inhaledAtmospheric air:PO2 = 159 mmHgPCO2 = 0.3 mmHgAlveolar air:PO2 = 105 mmHgPCO2 = 40 mmHgOxygenated blood:PO2 = 100 mmHgPCO2 = 40 mmHgDeoxygenated blood:PO2 = 40 mmHgPCO2 = 45 mmHgSystemic tissue cells:PO2 = 40 mmHgPCO2 = 45 mmHgPulmonary capillaries(a) External respiration:pulmonary gasexchange(b) Internal respiration:systemic gasexchangeSystemic capillariesTo lungsTo right atriumTo left atriumTo tissue cellsAlveoliCO2O2CO2O2VII. External vs Internal Respiration External Respiration:– oxygen will diffuse from the alveoli into the pulmonary capillaries– CO2 moves in the opposite direction Internal Respiration:– oxygen will diffuse from the systemic capillaries into the tissue– CO2 moves in the opposite directionVIII. Transport of O2 and CO2 in the Blood Oxygen:– 1.5% of the O2 is dissolved in the plasma– 98.5% of the O2 is carried by hemoglobin (Hb) Carbon Dioxide:– 7% of the CO2 is dissolved in the plasma– 23% of the CO2 is carried by Hb inside red blood cells as carbaminohemoglobin – 70% of the CO2 is transported as bicarbonate ions (HCO3) IX. Hemoglobin- binding affinity decreases intissues Higher Po2 the more O2binds to Hb Only 20–25% of bound O2 is unloadedduring one systemic circulation If O2 levels in tissues drop:– More oxygen dissociatesfrom hemoglobin and is usedby cells – Respiratory rate or cardiacoutput need not increase– pH and PCO2 and Temperature also affect Hemoglobin Saturation As cells metabolize glucose– Pco2 and H+ increase in concentration in capillary blood =Declining pH weakens the hemoglobin-O2 bond (Bohr effect)– Heat production increases=Increasing temperature directly and indirectly decreases Hb affinity for O2 – Fetal Hemoglobin= higher affinity for oxygen than adult hemoglobinX. O2 and CO2 Transport during External and Internal Respiration Haldane Effect:– The amount of CO2 transported is affected by the Po2– The lower the Po2 and hemoglobin saturation with O2, the more CO2 canbe carried in the blood– At the tissues, as more carbon dioxide enters the bloodo More oxygen dissociates from hemoglobin (Bohr effect)o As HbO2 releases O2, it more readily forms bonds with CO2 to form carbaminohemoglobinXI. Medullary Rhythmicity Area Control of Respiration Involves neurons in the reticular formation of the medulla and pons Depth and Rate of Breathing is controlled by the medullary rhythmicity areao Depth is determined by how actively the respiratory center stimulates the respiratory muscleso Rate is determined by how long the inspiratory center is activeXII. Control of Respirationa. Cortical influenceso Allow conscious control of respiration that may be needed to avoid inhaling