22.3
肺活量
肺中的空气以体积和容量来测量。肺容积测量反映了肺功能吸入，释放或遗留的空气量，如单次吸入。肺容量测量值是两个或更多肺容量测量值的总和。
有四种定义的肺容积测量：潮气容积、吸气储备容积、呼气储备容积和残余容积。
潮气量是正常呼吸时吸入和呼出的空气量。吸气（吸入相关）储备量是指在定期吸气后可吸入的额外空…
肺部大小 可能因经验和体型而异。 可以进入或离开肺部的空气量 被测量为四个体积， 单一功能，如吸气， 和四个能力， 多卷的比较数量。 通常吸入和呼出的空气量 被称为潮气量， 而在正常吸气或呼气后 可以进一步吸入或吸出的空气 被称为吸气 和呼气储备量。
第四个体积是 留在肺部的空气量 在呼气储备量之后， 被称为剩余储备量， 少量空气不会离开肺部 保持肺部充气。 这个数量与其他数量相结合 是总肺容量， 肺部可容纳的全部空气量， 为大约六升。 在一个呼吸周期内， 可移动的最大空气量或 我们的肺活量， 基本上是潮汐和 两个储备量的总和。 剩余容量是吸气能力， 正常呼气后可以吸入多少 和功能剩余容量， 呼气后剩余多少空气。 最终这些测量 用于诊断肺部疾病， 像哮喘，肺部有更多的空气 需要更长的呼气时间 或体积迅速排空的肺纤维化 导致呼吸短促。
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Q1: What is the difference between lung volumes and lung capacities?
Lung volumes measure air during single respiratory functions like inhalation or exhalation, while lung capacities represent sums of two or more volume measures. There are four lung volumes: tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. Four capacities combine these volumes to show total air movement potential during breathing cycles.
Q2: How much air does tidal volume represent in normal breathing?
Tidal volume is the amount of air normally inhaled and exhaled during a regular breath without forced effort. This is the baseline air movement during quiet, resting breathing. It represents the air exchanged during each normal respiratory cycle before any reserve volumes are engaged.
Q3: What is residual volume and why does it matter?
Residual volume is the small amount of air remaining in the lungs after forced exhalation, keeping the lungs inflated and preventing collapse. This air cannot be voluntarily expelled. Combined with other volumes, residual volume contributes to total lung capacity, approximately six liters in adult males and 4.2 liters in adult females.
Q4: What does vital capacity measure during breathing?
Vital capacity is the maximum volume of air that can be exhaled after maximal inhalation, representing the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume. It measures the maximal amount of air that can be moved in or out during a single respiratory cycle, excluding residual volume.
Q5: How do inspiratory and expiratory reserve volumes differ?
Inspiratory reserve volume is the additional air that can be inhaled after normal inhalation, while expiratory reserve volume is the extra air that can be exhaled after normal exhalation. Together with tidal volume, these reserves determine how much extra breathing capacity exists beyond routine respiration and are essential for activities requiring increased oxygen intake.
Q6: How are lung capacity measurements used to diagnose respiratory diseases?
Lung capacity measurements help identify diseases by revealing abnormal air retention or rapid emptying patterns. In asthma, more air remains in the lungs, prolonging exhalation. In pulmonary fibrosis, lung volume empties rapidly, causing shortness of breath. These measurements provide objective data for diagnosing and monitoring respiratory conditions.
Q7: What is functional residual capacity and how is it calculated?
Functional residual capacity is the volume of air remaining in the lungs after normal exhalation, calculated as the sum of expiratory reserve volume and residual volume. This measurement shows how much air stays in the lungs during quiet breathing and is important for understanding gas exchange and transport during the respiratory cycle.