Question

Чтобы вдохнуть воздух,человек при помощи мышц расширяет грудную клетку.Почему воздух при этом входит в лёгкие? Как происходит выдох?

Answer 1

Если принять, что температура тела у человека постоянная , то при вдохе происходит изотермическое расширение. Следовательно, давление в легких должно падать, а воздух перемещается из зоны более высокого давления в зону низкого давления. Происходит вдох. При выдохе все наоборот!

Answer 2

The Process of Breathing

When a person inhales, they expand their chest cavity with the help of muscles, which in turn allows air to enter the lungs. The process of breathing involves the diaphragm and intercostal muscles.

Inhalation: During inhalation, the diaphragm contracts and moves downward, while the intercostal muscles contract and lift the ribcage. These actions increase the volume of the chest cavity, creating a negative pressure inside the lungs. As a result, air from the surrounding environment rushes in to equalize the pressure, filling the lungs with oxygen-rich air.

Exhalation: Exhalation, or the process of breathing out, is a passive process that does not typically require muscle contraction. When the muscles involved in inhalation relax, the diaphragm moves upward and the intercostal muscles relax, causing the chest cavity to decrease in volume. This decrease in volume increases the pressure inside the lungs, forcing air out of the respiratory system.

It's important to note that during physical exertion or certain respiratory conditions, additional muscles may be involved in the process of exhalation to forcefully expel air from the lungs.