動(dòng)物生理學(xué)5呼吸系統(tǒng)生理上(參考版)
2025-05-17 17:17本頁面
【正文】 thus delivery of O2 aids in buffering acids produced locally in the tissue. 影響氧解離曲線的因素 factors effect oxygen dissociation curve 。 √MW The partial pressure of respiratory gases at different parts of the body Gas Exchanges in the Lung The exchange of gases in the lung between the inspired air and the blood is governed by several important physiological mechanisms. In an ideal cardiorespiratory system, perfect equilibration between the air and the blood might be expected. This would provide optimal efficiency in gas exchange. Unfortunately , the lung is always somewhat inefficient, even in normal individuals. This inefficiency is manifested(表示 ) as a difference between alveolar Po2 and arterial Po2. With lung disease or some circulatory abnormalities, the difference can be large. Pulmonary capillary gas equilibration Under the normal circumstances, the blood spends an average of seconds in the pulmonary capillary. With a normal diffusion capacity , enough oxygen crosses the membrane to bring the red cell hemoglobin to equilibrium with the avoelar Po2 in seconds or less. Factors affecting gas exchange in the lung The thickness of alveolocapillary (respiratory) membrane surface lining (surfactant), alveolar epithelium, basement of membranes, capillary endothelium. The area of respiratory membrane about 3x108 alveoli total 70 m2, 40 m2 at resting state ( Venti
高考資料相關(guān)推薦
鄂ICP備17016276號(hào)-1