VENTILATION AND GAS-EXCHANGE IN THE MUTE SWAN, CYGNUS-OLOR
VENTILATION AND GAS-EXCHANGE IN THE MUTE SWAN, CYGNUS-OLOR
复制标题
DOI：
10.1016/0034-5687(80)90060-2
复制
发表时间：
1980-01-01
期刊：
影响因子：
--
通讯作者：
JOHANSEN, K
中科院分区：
文献类型：
--
作者：
BECH, C;JOHANSEN, K
采用呼吸描记法和呼吸-呼吸分析法结合血气分析，连续测量了疣鼻天鹅的通气和气体交换。呼吸频率低得多，潮气量远高于异速生长关系预测值。呼吸周期通常显示长吸气末屏气期。潮气末PCO 2 [CO2分压]和PO 2 [O2分压]分别高于和低于鸟类典型的潮气末气体张力。潮气末气体和混合静脉血之间存在明显的正PCO 2差异，平均为9.8 mm Hg。疣鼻天鹅的血气值属于鸟类的典型范围。非常低的空气对流要求（13.6ml. ml ~（-1）和较高的氧提取系数（33.0%）表明天鹅肺具有较高的气体交换效率。异常大的潮气量和每次吸气后的长时间屏气可能是高交换效率的因素。血液对流要求的计算低值（12.8 ml. ml-1）匹配低的空气对流要求，并导致通气/灌注比接近1（≥ VI/≥ Q = 1.06）。
Ventilation and gas exchange were continuously measured in the mute swan using pneumatochography and breath-to-breath analysis of the ventilated gas by mass spectrometry combined with blood gas analysis. The breathing frequency was much lower and the tidal volume much higher than values predicted from allometric relations. The breathing cycles typically showed long end-inspiratory breath holding periods. End-tidal PCO2 [CO2 partial pressure] and PO2 [O2 partial pressure] were above and below, respectively, typical end-tidal gas tensions in birds. A pronounced positive PCO2 difference between end-tidal gas and mixed venous blood was present, averaging 9.8 mm Hg. The blood gas values in the mute swan fall within a range typical of birds. A very low air convection requirement (13.6 ml .cntdot. ml-1) and high O2 extraction coefficient (33.0%) indicate a high gas exchange efficiency of the swan lung. The unusually large tidal volumes and the long breath holds succeeding each inspiration are likely contributing factors to the high exchange efficiency. Calculated low values for the blood convection requirement (12.8 ml .cntdot. ml-1) match the low air convection requirements and result in a ventilation/perfusion ratio near unity (.ovrhdot.VI/.ovrhdot.Q = 1.06).