The Respiratory System & Breathing

The respiratory system includes the lungs and airways as well as the mechanics of breathing, respiratory volumes and VO2 max. Select from the options below to view more detailed information.

The function of the human respiratory system is to transport air into the lungs and to facilitate the diffusion of Oxygen into the blood stream. Its also receives waste Carbon Dioxide from the blood and exhales it. Here we explain the anatomy of the airways and how oxygen gets into the blood.

The action of breathing in and out is due to changes of pressure within the chest (thorax). This action is also known as external respiration, and is created by the muscles of the chest and the diaphragm changing the size of the chest cavity (and air pressure). Here we explain the mechanics of breathing and how breathing is regulated at rest and during exercise.

Respiratory volumes

Respiratory volumes are the amount of air inhaled, exhaled and stored within the lungs at any given time. There are a number of different measurements and terms which are often used to describe this including tidal volume, inspiratory reserve volume, residual volume, vital capacity and more. Here we explain the main respiratory volumes.

VO2 max is the measure of the peak volume of Oxygen (VO2) you can consume and use in a minute and is a popular measure of an athletes aerobic fitness. It is measured in ml/kg/min. The per kilogram part means that an athletes bodyweight is taken into account. Oxygen is needed to produce energy and the harder you exercise the more Oxygen you use in order to produce sufficient energy. However, everybody has a maximum level (their VO2 Max), where Oxygen utilisation is at its peak.

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