Breathing

External respiration

Occurs when gases are exchanged between the pulmonary blood vessels and the alveoli.

Internal respiration

Occurs when the blood exchanges gases with the body tissues throughout the body.

Ventilation

The process that precedes external respiration, also known as breathing.

Diaphragm

A muscle connected to the ribs at the bottom of the chest cavity, involved in breathing.

External intercostal muscles

Muscles located between the ribs, involved in the breathing process.

Inspiration

The process where muscle contraction leads to an increase in lung size and decrease in pressure, causing air to rush in.

Expiration

The process where muscle relaxation leads to a decrease in lung size and increase in pressure, causing air to rush out.

Tidal volume

The amount of air that is exchanged by the lungs at rest.

Inspiratory reserve volume

The additional amount of air that can be inhaled consciously.

Expiratory reserve volume

The additional amount of air that can be exhaled consciously.

Residual volume

The amount of air remaining in the lungs after a forced exhalation.

Vital capacity

The amount of air someone can consciously exchange with the environment (inhaling and exhaling).

Total lung capacity

The sum of vital capacity and residual volume, approximately 6 liters for adult men, and 10% less for adult females.