How do respiratory muscles like the diaphragm assist in breathing?

Respiratory muscles like the diaphragm assist in breathing by contracting and relaxing to change the volume of the thoracic cavity.

The diaphragm, a dome-shaped muscle located at the base of the lungs, plays a crucial role in the process of respiration. When you inhale, the diaphragm contracts and moves downward, increasing the space in your chest cavity and allowing your lungs to expand. This decrease in pressure allows air to flow into the lungs. Conversely, when you exhale, the diaphragm relaxes and moves upward, decreasing the space in your chest cavity and forcing air out of the lungs.

Other respiratory muscles, such as the intercostal muscles between the ribs, also contribute to the breathing process. These muscles contract to lift the rib cage during inhalation, further increasing the volume of the thoracic cavity and aiding in the inflow of air. During exhalation, these muscles relax, allowing the rib cage to lower and decrease the volume of the thoracic cavity, aiding in the outflow of air.

The coordinated action of the diaphragm and other respiratory muscles is controlled by the respiratory centre in the brain, which sends signals via nerves to contract or relax these muscles based on the body's oxygen and carbon dioxide levels. This process of inhalation and exhalation, facilitated by the contraction and relaxation of respiratory muscles, is essential for the exchange of gases in the lungs, allowing oxygen to be absorbed into the bloodstream and carbon dioxide to be expelled from the body.

In summary, the diaphragm and other respiratory muscles play a vital role in the process of breathing. Their contraction and relaxation alter the volume of the thoracic cavity, enabling the flow of air into and out of the lungs.