What are the four respiratory events in human body?

The four main respiratory events in the body are:

1. Inspiration (Inhalation): This is the process of taking air into the lungs. It is an active process that involves the contraction of the diaphragm and the intercostal muscles. The diaphragm is a large muscle located at the bottom of the ribcage. When it contracts, it moves downward, increasing the volume of the thoracic cavity. The intercostal muscles are located between the ribs. When they contract, they pull the ribs upward and outward, further increasing the volume of the thoracic cavity. As the thoracic cavity expands, air is drawn into the lungs through the nose or mouth.

2. Expiration (Exhalation): This is the process of releasing air from the lungs. It is a passive process that occurs when the diaphragm and intercostal muscles relax. As the diaphragm relaxes, it moves upward, decreasing the volume of the thoracic cavity. The intercostal muscles also relax, allowing the ribs to move downward and inward, further decreasing the volume of the thoracic cavity. As the thoracic cavity decreases in volume, air is expelled from the lungs through the nose or mouth.

3. Gas exchange: This is the process by which oxygen and carbon dioxide are exchanged between the lungs and the bloodstream. Oxygen is taken up by the red blood cells in the lungs, while carbon dioxide is released from the red blood cells.

4. Transportation: This is the process by which oxygen is transported from the lungs to the tissues, and carbon dioxide is transported from the tissues to the lungs. Oxygen is transported by the red blood cells, while carbon dioxide is transported by the plasma.