1、呼吸系统生呼吸系统生理理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
2、力呼吸forced breathing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 depl
3、ete it slowlyDeep Diving 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
4、 our blood.Weddell seal holds 5% 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
