What is the process of exhalation?
During this process, the chest wall expands out and away from the lungs. Upon exhalation, the lungs recoil to force the air out of the lungs. The intercostal muscles relax, returning the chest wall to its original position. During exhalation, the diaphragm also relaxes, moving higher into the thoracic cavity.
When you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.
- medical Definition of expiration. 1 a (1) : the act or process of releasing air from the lungs through the nose or mouth : exhalation. (2) : the escape of carbon dioxide from the body protoplasm (as through the blood and lungs or by diffusion) b archaic : the last emission of breath : death.
- When you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.
- The muscles of respiration are those muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity. The diaphragm and, to a lesser extent, the intercostal muscles drive respiration during quiet breathing.
the steps of exhalation.
- step.1. the intercostal muscles relax.
- step.2. this causes the ribcage to move down and in.
- step.3. diaphragm muscles relax and shape the diaphragm as a dome.
- step.4. this causes a decrease in the volume of the rib cage and an increase in the air pressure.
- The diaphragm is attached to the base of the sternum, the lower parts of the rib cage, and the spine. As the diaphragm contracts, it increases the length and diameter of the chest cavity and thus expands the lungs. The intercostal muscles help move the rib cage and thus assist in breathing.
- Oxygen and carbon dioxide move from where there is a large concentration to where there is a lower concentration. This movement is called diffusion. Oxygen diffuses from the alveoli, into the blood in the capillaries. Similarly, carbon dioxide from the blood moves out of the capillaries into the alveoli.
- Carbon dioxide is the waste product of the respiritory system, and of several other chemical reactions in the body, such as the creation of ATP. Pure carbon cannot be transported in the body, so CO2 is one form it takes that is water soluble. Levels of CO2 also tell the body when it needs more oxygen.
The process of breathing (respiration) is divided into two distinct phases, inspiration (inhalation) and expiration (exhalation). During inspiration, the diaphragm contracts and pulls downward while the muscles between the ribs contract and pull upward.
- When breathing for life, inhalation is active involving many muscles and exhalation is passive.
- Inspiration occurs when intrapulmonary pressure falls below atmospheric pressure, and air moves into the lungs. Expiration occurs when intrapulmonary pressure is increased above atmospheric pressure. After the diaphragm contracts, it relaxes, thus decreasing thoracic volume and increasing intrapulmonary pressure.
- Because a negative pressure that is lower than atmospheric pressure is created in the lungs, this type of breathing is called negative-pressure breathing. Again, breathing out is usually passive. The diaphragm and rib (intercostal) muscles relax and everything that happened to allow the mammal to breathe in reverses.
Updated: 2nd October 2019