10When intercostal muscles contract or relax, the volume of chest expand or recoil, then the volume of lungs expand or recoil. Why?
11Pleural cavity is made up of two layers of pleura.One is visceral layer stick to the surface of lung and the other isparietal layer stick to thorax .There is only little liquid in the pleural cavity but not gas.The effect of this layer of liquid is :（1）The power between liquid molecules pastes two layers of pleura to make them tightly.（2）Lubrication effect between two layers of pleura.
12Section B Pulmonary ventilation Pulmonary ventilation is the gas exchange process between lungs and environment.
13Mechanics of Pulmonary Ventilation: Two factors:One is the power to push gas flowing.The other is resistance to prevent gas flowing.The former must overcome the latter , and thenpulmonary ventilation can be completed.
14Ⅰ the force that causes Pulmonary Ventilation 1. Respiratory movementThoracic expansion and contraction caused by respiratory muscles are named respiratory movement. (inspiration, expiration)
15Muscles of inspiration : diaphragm and external intercostal musclesMuscles of expiration : internal intercostal muscles and abdominal musclesEupneadeep breathing
16The Process of eupnea:Inspiration: inspiration muscles contract thoraxes expand lungs expand lung volumes increase intrapulmonary pressure decreases gas enters lungsExpiration: diaphragm and external intercostal muscles relax thorax recoils lung recoils intrapulmonary pressure increases gas is removed.
19patterns : Abdominal breathing Thoracic breathing Eupnea Normal quiet breathing is accomplished almost entirely by movement of the diaphragm.Abdominal breathingThoracic breathingBreathing caused primarily by the movement of external intercostal muscles.Eupneadeep breathingBreathing at rest is calm.Respiratory movement is greatly enhanced.
202. intrapulmonary pressure Intrapulmonary pressure is the pressure in pulmonary alveoli.Intrapulmonary pressure is equal to atmospheric pressure when apnea , vocal cord is open.
21At the first of inspiration, lung volume increases and intrapulmonary pressure decreases below atmospheric pressure. Air enters alveoli under the pressure difference. Intrapulmonary pressure increases as the increasing of gas in lung. At the last of inspiration, intrapulmonary pressure is equal to atmospheric pressure and the air flow stops.
22At the first of expiration, lung volume decreases and intrapulmonary pressure increases until it exceeds atmospheric pressure. Air outflows lungs and intrapulmonary pressure decreases by and by. Intrapulmonary pressure is equal to atmospheric pressure at the last of expiration.
23Artificial respiration: once respiration stops, intrapulmonary pressure can be changed factitiously . Pressure difference between intrapulmonary pressure and atmospheric pressure can be created to maintain pulmonary ventilation .
243. Intrapleural pressure Intrapleural pressure is usually negative pressure.At the end of expiration of eupnea,the pressure is about -5~ -3mmHg.At the end of inpiration of eupnea, the pressure is about -10~ -5mmHg.
25Intrapleural pressure＝ intrapulmonary pressure－lungs recoil At the end of respiration or inspiration, intrapulmonary pressure equals atmospheric pressureintrapleural pressure= － lungs recoil
26If pleura breaks, pleural cavity will be open to atmosphere and air will enter pleural cavity . This is called pneumothorax. At this time , two layers of pleura separate and lungs contract for the elastic recoil.
27Power of Pulmonary Ventilation (Summary) Expansion and contraction of respiration muscles expansion and contraction of thoracic cage (lungs change with the moving of thoracic cage)lung volumes change pressure differences between lung volume and atmospheric pressure gas enters or is removed out of lungs.
28Ⅱ Resistances to Pulmonary Ventilation one is elastic resistance (70％)（ the main resistance of eupnea ）elastic resistance of lungelastic resistance of thoraxthe other is non- elastic resistance( 30％)airway resistanceinertial resistanceviscous resistance of organization
291. Elastic Resistance and Compliance ☆The ability of an elastic structure to resist stretching or distortion is named elastic resistance.Compliance is the expandability of elastic tissue when acted on by foreign forces.Relationship between compliance and elastic resistanceC＝1 / RE.g. an elastic band☆☆Compliance is inversely proportional to elastic resistance, that is, the larger the compliance, the less elastic properties, and vice versa.
30（1）Elastic Resistance of Lungs and Compliance change of lung volume （△V）lungs compliance ＝change of transpulmonary pressure （ △P）transpulmonary pressure is the difference betweenintrapulmonary pressure and pleural pressure.(L/cmH2O)
31Water manometerConnect tracheal intubationinjectorThree-way tap
32① Lung static compliance diagram If curve slope is large , it means the compliance is large and the elastic resistance is small.If curve slope is small, it means the compliance is small and the elastic resistance is large.transpulmonary pressure(cmH2O)Lung volume change
34Lung compliance is also influenced by the total capacity of the lung. ②Specific complianceSpecific compliance = Measured lung compliance （L/cmH2O）/ Total lung capacity （L）Lung complianceTotal lung capacitySpecific complianceadultinfant
35③ Source of lungs elastic resistance a. The elastic recoil power of lungselastic recoil powerb. The recoil power caused by surface tension between the liquid layer of inner alveoli and gas in alveoli.liquid layerAlveolar surface tensionsurface tensionbead
36Retraction force can be calculated by Formula Laplace . Retraction force P = 2T / rT： surface tension dyn/cmr： alveoli radius （cm）
37(2) Pulmonary Surfactant Alveolar surface tensionliquid layerDPPC is an important pulmonary surfactant in the the liquid layer of inner alveoli, DPPC binding to apolipoprotein exist as lipoprotein.DPPC
39physiological effect of pulmonary surfactant （1） Lower alveolar surface tension and reduce inspiration resistance.（2）Accommodate surface tension and stable alveolar pressure.（3） The effect of suction is reduced. Reduce the producing of alveolar liquid and prevent pulmonary edema.
40development of Pulmonary surfactant occurent from cyesising 25－30 weeksat the high point in cyesising 40 weeksPremature may get respiratory distress syndrome even to death for deficiency of pulmonary surfactant and formation of pulmonary atelectasis.
431. Pulmonary VolumeTidal Volume(TV) : amount of air inhaled or exhaled in one quiet breathing. 500mLInspiratory reserve volume (IRV) : the maximum extra volume of air that can be inspired over and above the normal tidal volume mL
44● Expiratory reserve volume (ERV ): the maximum extra volume of air that can be exspired by forceful expiraton after the end of a normal tidal expiraton mL● RV(residual volume): amount of air remaining in the lungs after maximum expiraton mL
452. pulmonary capacities● Inspiratory Capacity (IC):maximum amount of air that can be inhaled after a normal tidal expiration. = TV + IRV 2000－2500 mL● Functional residual capacity (FRC): amount of air remaining in the lungs after a normal tidal expiration .= RV+ERV mL
46vital capacity (VC ): amount of air that can be exhaled with maximum effort after maximum inspiration. = TV+ IRV +ERV ♀ ♂3500mLtotal lung capacity (TLC): maximum amount of air that lungs can contain.=RV+VC3500－5000 mL
504.Dead space and Alveolar Ventilation physiologic dead space:anatomic dead spacealveolar dead space
51150500350150150150inspirationexspiration350250025001502500the end of exspirationthe end of inspiration
52alveolar ventilation = (tidal volume- dead space)× respiratory rate （500mL－150mL）×12次/分=350 ×12= 4200 L
53respiratory rate（time/min）tidal volume（ml）ventilation volume（ml/min）alveolar ventilation（ml/min）165008000560081000800068003225080003200If tidal volume decreases half, respiratory rate increases double. Minute ventilation volume keeps constant, but alveolar ventilation will decrease greatly. Considering as ventilation efficiency of slow and deep respiration is higher than fast and light respiration.
55Ⅰ principle of gas exchange gas diffusion:Gas molecules move freely among one another. The result is gas molecules diffuse from high-pressure area toward low-pressure area. The process is called gas diffusion.Exchange of gas in alveoli and tissues are physical diffusion processes .
56The volume of gas diffusion in unit time is called diffusion rate The volume of gas diffusion in unit time is called diffusion rate. It is effected by the following factors△P*T*A*SD∝d*√MW△P is the pressure difference between the two ends of the diffusion pathway, T is the temperature, A represents the cross-sectional area of the pathway, S is the solubility of the gas, d is the distance of diffusion, MW stands for the molecular weight of the gas.
571. Gas partial pressure difference: gas partial pressure difference is larger—diffuses faster 2. Gas molecular weight and solubility:when solubility is high, it diffuses fastwhen molecular weight is large,it diffuses slowly.
583. Diffusion area of alveolar membrane : when diffusion area of alveolar membrane is large,it diffuses fast★diffusion area of alveolar membrane is 40m2 in normal quiet state.★ diffusion area of alveolar membrane is 70m2 during sports.
605. Temperature of fluid increases Solubility increases—Diffuses fast 4. Diffusion distance—thickness of alveolar membrane(inverse ratio relationship)★ Pulmonary fibrosis★ Pulmonary edema5. Temperature of fluid increasesSolubility increases—Diffuses fastAverages 0.6 μm
616. Ventilation /Perfusion Ratio(VA/Q ) Ventilation/perfusion ratio is the rate between alveolar ventilation and pulmonary blood flow.VA: alveolar ventilation per minuteQ : pulmonary perfusion per minuteVA/Q (value of normal quiet state) ＝4.2L/5L＝0.84If blood flow decreases and gas exchange arenormal--the exchange total amount decreases. Soalveolar ventilation and blood flow must keep anappropriate ratio.
62★ventilation /perfusion ratio increases:it means partial alveolar gas can not exchange fully with the blood =physiological dead space increases.★ventilation /perfusion ratio decreases:it means partial blood flow through hypoventilation alveoli. They can not get fully exchange. And it equals functional arteriovenous shunt.
63When normal adult is standing, every part of lung VA / Q is not well-distributed Apex of lung : VA descent/Q descent, Q descenting is more obvious ratio rises(more than 3)Base of lung: VA descents/Q rises, ratio descents(0.6).
647. pulmonary diffusion capacity When all kinds of gas is under unit partial pressure difference,the gas volume(ml) passing through respiratory membrane per minute is called pulmonary diffusion capacity. It is the physiological index to test the diffusion ability of respiratory membrane.VDLPAPB
65CO2 diffusibility/ O2 diffusibility= √O2 molecular weight/ √CO2 molecular weight=√32/√44＝5.6/6.6 But because CO2 solubility/ O2 solubility= 0.592/0.0244=24.3/1.0(Herry’s law）CO2 diffusion velocity/ O2 diffusion velocity =（5.6/6.6）×（0.592/0.0244)=20.6/1.0From all above ,we know that the diffusion velocity of CO2 is much more than that of O2. There is no diffusion disturbance of CO2 in clinical.
66Ⅱ Pulmonary gas exchange PO2 of mixed venous blood is 5.32 kPa（40mmHg） is lower than kPa（104mmHg）of alveolar gas. O2 in alveolar gas diffuses to blood. PO2 in blood rises gradually until it is almost equal to PO2 in alveolar gas.
67PCO2 of mixed venous blood is 6. 12kPa（46mmHg） It is higher than 5 PCO2 of mixed venous blood is 6.12kPa（46mmHg） It is higher than 5.32 kPa（40mmHg) of alveolar gas. CO2 in blood diffuses to alveolar gas. PCO2 in blood descents gradually until it is almost equal to PCO2 in alveolar gas.
72Section D Gas Transport Ⅰ Existing forms of O2 and CO2 in the bloodphysical dissolution(medium)two formschemical combination(primary)lungtissueO2physical dissolutioncombinationphysical dissolutionO2CO2physical dissolutioncombinationphysical dissolutionCO2
73Ⅱ oxygen transportation 98.5％ binding to Hboxygen transportation1.5％ physical dissolution
75Maximum capacity of hemoglobin binding with O2 (in every 100ml blood ) is named oxygen capacity. When normal Hb is in 15g/100ml blood , 1g Hbbinds with 1.34ml O2.Oxygen capacity= 15×1.34＝20mlThe volume of hemoglobin binding with oxygen (in fact or really) is called oxygen content.arterial blood: 20ml O2venous blood: 15ml O2
76The percentage of oxygen content to oxygen capacity is called oxygen saturation. In arterial blood, oxygen content equals 20ml and oxygen saturation is 100%.In venous blood , oxygen content equals 15ml and oxygen saturation is 75%.(=×100%)
77（一） Hb＋O2 HbO2 reduction 、royal blue oxygenation、red break tension O2 partial pressure is higher(lung)Hb＋O HbO2O2 partial pressure is lower(tissues)reduction 、royal blue oxygenation、redbreaktensionrelaxationform
78character PO2↑ Hb + O2 HbO2 PO2↓ 1. Reversible binding. Without enzyme. Fast. Effected by PO2.2. O2 binds with Fe2+ of hemoglobin . The iron value is permanent. So the process is called oxygenation but not oxidation.
793. Globin of hemoglobin is made up of two αpeptide chains and two β peptide chains . There is a protoheme molecular on each peptide chain including a Fe2+. Each Fe2+ binds with an O2 . So each hemoglobin can bind with four O2.Fe
804. O2 can facilitate binding or releasing. In lungs, increasing of PO2 promotes combination.In tissues, decreasing of PO2 promotes releasing.PO2↑Hb + O2HbO2PO2↓
815. The binding or releasing curves of Hb and O2 appear S form 5. The binding or releasing curves of Hb and O2 appear S form.This is related to the allosterism effect of Hb.Hb binds with O2—salt bond breaks, R formHb releasing with O2—salt bond forms,T formThe affinity of T form to O2 is smaller.The affinity of R form to O2 is larger.tensionrelaxationHbHbO2
82（二） oxygen dissociation curve The curve reacts the relationship of PO2 and saturation of oxygenation Hb .
83oxygen dissociation curve character 1. Superior segment of curve: PO2 60－100mmHg. Slope is flat.Partial pressure of oxygen changes greatly. But oxygen saturation changes little—even PO2 of environment or alveoli descents, oxygenation saturation will maintain high level.
84Significance:Hemoglobin amortization function: even blood itself of environment oxygen change greatly, tissue PO2 still remain in normal range.PO2 descents in plateau
852. Middle segment of curve PO2 60－40mmHg is the part that HbO2 releases O2. e.g. venous blood PO2 level
863. Inferior segment of curve . PO2 10－40mmHg . The slope is steep. PO2 descents a little. It makes oxygen saturation descent greatly. This is benefit to supplying oxygen for tissue activity.
87（三） factors effect oxygen dissociation curve T increases, the concentration of H+, CO2, 2，3-DPG rises, pH descents . Curve move to right. Oxygen saturation descents and dissociation increases.And vice versa.
882，3－DPG is a kind of organophosphate in RBC. 缺氧、贫血hypoxia, anemia长时间运动 long time sportsRBC ，3DPG increases
92（一）Transport in bicarbonate pattern character:1. Reaction is reversible. But it need the help of enzyme(CA).2. Conjugation or dissociation is decided by partial pressure difference of CO2.3. There is the transfer of Cl－ in the reaction.
93in tissues （二）Transport in carbaminohemoglobin pattern HbNH2+CO HbNHCOOHlungHbNHCOO－ ＋H＋
94character 1. Reaction is reversible and need not the help of enzyme. 2. Conjugation or dissociation is decided by theoxygenation effect of Hb.Much Deoxy Hb binds with CO2.Little Hb binds dissociation is much.3. The effect of partial pressure difference is not obvious.in tissuesHbNH2+CO HbNHCOOHlungHbNHCOO- ＋ H+carbaminohemoglobin
95Regulation of Respiration Section ERegulation of Respiration
96Ⅰ respiratory centerRespiratory center is composed of several groups of nerve cells which produce and regulate respiratory movement in central nervous system.
97Lumsden experiment in year 1923 Cross-cut site Patterns of respiration Patterns of respiratorymovement after cutting vagus nerveBetween pons Normal Deeper and slowerand midbrainIn the middle Deeper and slower Apneusisof ponsBetween Pons Anomalo-respiration Pant respirationand medullaBetween medulla Respiration arrests Respiration arrestsand spinal cord
98Conclusion: Superior part of pons -- pneumotaxic respiratory center medulla --basic respiratory centerspinal cord--primary respiratory center
99Regulation of Cerebral Cortex to Respiration 1. Liberty Regulation and Creation of respiration Conditioned reflex.2. Coordination with the process of language activity.Clinical: Descending pass of spinal cord pro-Lateral funiculus is damaged.---Autonomous breathing arrests. Regulate through voluntary breathing. Use breathing machine during sleeping .Oden’s curse
101Reversion inhibition theory(part neuronal circuit feedback and controling theory) 1）Central inspiratory activity2）inspiratory off-switch mechanism central inspiratory activity inspiration-initiative processexpiration-passive -process
1023） The mechanism of changing from expiratory phase to inspiration—there are probably a group of cutting off expiratory neurs.Imagining the process of expiration phase is probably controled by a mechanism of inhibiting inspiration ability during respiration phase. The ability degree of this mechanism is getting weaker during the expiration phase.once reaching the critical level, the inhibition of inspiration ability is relieved and the next inspiration will begin.
103Ⅲ Reflex Control of Breathing Respiratory movement can be regulated , accelerated or inhibited by all kinds of stimulus to the body.
104（一）Chemical Control of Breathing 1 . Chemoreceptor（1） peripheral chemoreceptorCarotid body and aortic body: stimulated when PCO2 in blood increases, PO2 in blood decrease, H+ Concentration in blood increase.
106Abdomen Lateral of central chemoreceptor feel the stimulation of H+ change in the Cerebra Spinal Fluid.charactera. Not feel the stimulation of deficiency of O2.b. H+ in the blood has no effect to it. For it isdifficult to pass the blood brain barrier.
107c. The sensibitity to CO2 is higher than that to peripheral chemoreceptor. But the latent period of reaction to sudden change of PCO2 in the arterial blood is longer than that of the peripheral chemoreceptor.d. Utility stimulant is not CO2 itself but the increase of H+ caused by CO2.
1092. Regulation of CO2、H+ 、O2 to respiration （1） Influence of CO2 to respirationa. Act indirectly to central chemoreceptor(main pathway)b. Act directly to peripheral chemoreceptor.The sensibitity of central chemoreceptor to H＋is about 25 times of that of peripheral chemoreceptor.
111（2）Effect of O2 to respiration 1）charactera. Hypoxia stimulation act through peripheral chemoreceptor. If the inputing of peripheral chemoreceptor is cut, the stimulation effect disappear.b. The direct effect of hypoxia to center is light inhibition.
1122）The pathway of hypoxia regulating respiration The main pathway is acting directly on peripheral chemoreceptor and inputting impulse.respiration center is excited.
113（3）Effect of H+ to respiration 1）Increasing H+ or decreasing pH can faster respiration. It is the effective stimulator to chemoreceptor.2）Pathway of H+ regulating respirationa. H+ in blood increases—excites peripheral chemoreceptor mainlyb. H+ in Cerebra Spinal Fluid increases-- excites central chemoreceptor . Because H+ is very difficult to diffuses across the blood-brain barrier, so brain extracellular fluid [H+] increased very little.
115（4）Interface of PCO2、H+and PO2 effect respiration 1）PCO2 does main role in normal respiration regulation.2）When any of the three factor changes ,it can induce the continued change of the other factors.and it can change the respiration effect of the first factor changing .3）Hypoxia and increasing of H+ concentration can strengthen the stimulation effect of PCO2 increasing to respiration.
116150500350150150150inspirationexspiration350250025001502500the end of exspirationthe end of inspiration
117the alveolar ventilation reaction of changing any of the factors of PCO2，PO2，PH in Arterial blood but not controling the other two factors
122inflation reflex deflation reflex Pulmonary Pulmonaryinflation reflex deflation reflexPart of sensor Smooth muscle of bronchus and bronchioleStimulation property dilatate diminishEffect relax(expiration) Shrink(inspiration)Significance Urge inspiration urge expiration changechange into expiration into inspiration promptly,promptly,inhibit too deep inhibit too expiration.or too long inspiration.