1、PharynxLarynx(Esophagus)TracheaRight lungBronchusBronchioleDiaphragmHeartSEMLeftlungNasalcavityTerminalbronchioleBranch ofpulmonaryvein(oxygen-richblood)Branch ofpulmonaryartery(oxygen-poorblood)AlveoliColorizedSEM50 m50 m肺泡肺泡胸廓胸廓呼呼吸吸道道（一）肺通气的动力（一）肺通气的动力（）2.呼吸运动呼吸运动 平静呼吸平静呼吸eupnea用力呼吸用力呼吸forced brea
2、thing肺充血肺充血 肺纤维化肺纤维化呼吸频率呼吸频率 潮气量潮气量 肺通气量肺通气量 肺泡通气量肺泡通气量 (次次/min)/min)（ml ml）（ml/minml/min）（ml/minml/min）PcoPco2 2 Fig.42-27BreathingcontrolcentersCerebrospinalfluidPonsMedullaoblongataCarotidarteriesAortaDiaphragmRib muscles7.Deep-diving air-breathers stockpile oxygen and deplete it slowlyDeep Divin
3、g Breath-holding Adaptations to pressure Collapse of lung cavity(ribs)Collapse of lungs7.Deep-diving air-breathers stockpile oxygen and deplete it slowlyAdaptations to oxygen conservation Oxygen stores 2-3 x more than humansHumans:36%of our total O2 in lungs and 51%in our blood.Weddell seal holds 5%
4、of its O2 in its small lungs and stockpiles 70%in the blood.Skeletal muscles and blood as primary storage site(myoglobin)Weddell seal to store about 25%of its O2 in muscle,13%in humansDeep-diving air-breathers stockpile oxygen and deplete it slowlyAdaptations to oxygen conservation Reduce heart rate when diving (120 beats/min to 6 b/min)seals and sea lions store oxygenated blood in their extra-large spleen(which can be 45%of their body weight)Maintain blood flow to brain,heart
