What are the 2 main types of muscles in respiration and how do they work?

In the process of respiration, there are two types of muscles primarily responsible for the movement of air in and out of the lungs:

1. Diaphragm:

- The diaphragm is the primary muscle of respiration.

- It is a dome-shaped muscle located at the bottom of the ribcage, separating the thoracic cavity (chest) from the abdominal cavity.

- When the diaphragm contracts, it moves downward and flattens, creating a larger thoracic cavity.

- This decrease in pressure within the thoracic cavity causes air to rush into the lungs, resulting in inhalation (inspiration).

- When the diaphragm relaxes, it moves back to its original position, compressing the lungs and pushing air out, resulting in exhalation (expiration).

2. Intercostal Muscles:

- The intercostal muscles are located between the ribs.

- There are two sets of intercostal muscles: external intercostal muscles and internal intercostal muscles.

- The external intercostal muscles are located between the ribs and are responsible for inhalation. When these muscles contract, they pull the ribs upward and outward, expanding the thoracic cavity, which leads to a decrease in pressure and air is drawn into the lungs.

- The internal intercostal muscles are located deeper than the external intercostal muscles and are responsible for exhalation. When these muscles contract, they pull the ribs downward and inward, reducing the volume of the thoracic cavity, which increases the pressure and forces air out of the lungs.

When the diaphragm contracts and the intercostal muscles elevate the chest, the volume of the thoracic cavity increases, causing the pressure within the lungs to decrease. This lower pressure draws air in through the nose, resulting in inhalation. When the diaphragm relaxes and the intercostal muscles relax and lower the chest, the volume of the thoracic cavity decreases, increasing the pressure in the lungs and pushing air out through the nose and mouth as an exhaled breath.