动物生理学5.呼吸系统生理-上幻灯片.pptVIP

5 Respiration Chemical reduction of molecular oxygen to form water is the primary source of energy for animals. The principal site for the reaction occurs within the mitochondria. Without this reaction life cannot exist for more than seconds. Coincidental with the reduction of O2 is the production of CO2; this comes mainly from oxidative phosphorylation of glucose which also occurs principally in the mitochondrion. Repiration includes: The gases must be moved between the environment and the lungs, usually referred to as “pulmonary ventilation” The gases must be exchanged between the spaces in lung and the blood Exchange of gases between the blood and the various tissues must occur Finally transfer of gases must occur within the tissue to sites of utilization (for O2 ) and from the sites of production (for CO2) 5.1 pulmonary ventilation Gas exchange between the environment and the lungs, usually referred to as “pulmonary ventilation” The structures needed for pulmonary ventilation: airway, alveoli [?l’vi?lai] (单数 alveolus ), and thorax 5.1.1　肺通气的原理 5.1.1.1 肺通气的动力 　　直接动力　肺泡与外界环境之间的压力差 　　原动力　节律性呼吸运动 Respiratory movements (呼吸运动） 　　Respiratory muscle: diaphragm(膈), intercostal muscle, et al 　　Thoracic cavity 　　Inspiratory movement Expiratory movement 　呼吸运动的形式： 　　腹式呼吸和胸式呼吸 　　平静呼吸和用力呼吸 Intrapulmonary pressures 肺内压 平静呼吸 吸气时 -2~ -1 mmHg (-0.266~ -0.133Kpa) 呼气时 1~ 2 mmHg (0.133~ 0.266Kpa) 用力呼吸 (forced breathing) 用力吸气　-100~ -30 mmHg 用力呼气　60~ 140 mmHg The pressure in thoracic cavity (intrapleural pressures)　胸膜腔内压 pulmonary ventilation: As long as interplueral pressure remains less than atmospheric pressure, the dimensions of the lungs follow closely the dimensions of the thoracic cavity. Lung movements results from contraction of respiratory muscles associated with the movement of structures in thoracic cavity wall and of the diaphragm. Pleura ： surrounding each lung is a serous (含浆液的）membrane, the pleura. The out