exhalation

Examples of exhalation in the following topics:

• Lung Volumes and Capacities

  • The expiratory reserve volume (ERV) is the additional amount of air that can be exhaled after a normal exhalation.
  • It is the reserve amount that can be exhaled beyond what is normal.
  • Patients exhale most of the lung volume very quickly.
  • It takes a long time to reach the maximal exhalation volume.
  • The FRC measures the amount of additional air that can be exhaled after a normal exhalation.

• Expiration

  • Expiration, also called exhalation, is the flow of the respiratory current out of the organism.
  • The purpose of exhalation is to remove metabolic waste, primarily carbon dioxide from the body from gas exchange.
  • The pathway for exhalation is the movement of air out of the conducting zone, to the external environment during breathing.
  • There are two groups of muscles that are involved in forced exhalation.
  • It is generally defined by holding air in the lungs and releasing it at a fixed rate, which enables control over when and how much air to exhale.

• The Work of Breathing

  • In these types of restrictive diseases, the intrapleural pressure is more positive and the airways collapse upon exhalation, which traps air in the lungs.
  • Forced or functional vital capacity (FVC), which is the amount of air that can be forcibly exhaled after taking the deepest breath possible, is much lower than in normal patients; the time it takes to exhale most of the air is greatly prolonged .
  • A patient suffering from these diseases cannot exhale the normal amount of air.
  • Those with obstructive diseases have large volumes of air trapped after exhalation.
  • The ratio of FEV1 (the amount of air that can be forcibly exhaled in one second after taking a deep breath) to FVC (the total amount of air that can be forcibly exhaled) can be used to diagnose whether a person has restrictive or obstructive lung disease.

• Factors Affecting Pulmonary Ventilation: Compliance of the Lungs

  • Measurements of lung volumes differ at the same pressure between inhalation and exhalation, meaning that lung compliance differs between inhalation and exhalation.
  • Exhalation of air also becomes much more difficult because the loss of elastic recoil reduces the passive ability of the lungs to deflate during exhalation.
  • Those with emphysema have considerable difficulty with exhaling breaths and tend to take fast shallow breaths and tend to sit in a hunched-over position in order to make exhalation easier.

• The Mechanics of Human Breathing

  • Both inhalation and exhalation depend on pressure gradients between the lungs and atmosphere, as well as the muscles in the thoracic cavity.
  • Upon exhalation, the lungs recoil to force the air out of the lungs.
  • During exhalation, the diaphragm also relaxes, moving higher into the thoracic cavity.

• The Respiratory System and Direct Diffusion

  • How often a breath is taken and how much air is inhaled or exhaled are tightly regulated by the respiratory center in the brain.
  • A respiratory cycle consists of an inhalation and an exhalation: with every normal inhalation, oxygenated air fills the lungs, while with every exhalation, deoxygenated air rushes back out.
  • CO2 is toxic and must be eliminated; thus, CO2 exits the cells, enters the bloodstream, travels back to the lungs, and is expired out of the body during exhalation.

• Types of Breathing

  • During exhalation, the lungs expel air and lung volume decreases.
  • Oxygenated air, taken in during inhalation, diffuses across the surface of the lungs into the bloodstream, while carbon dioxide diffuses from the blood into the lungs and is expelled during exhalation.
  • This directionality of airflow requires two cycles of air intake and exhalation to completely remove the air from the lungs .
  • Animation of a diaphragm exhaling and inhaling, demonstrating diaphragmatic breathing.
  • During exhalation, the diaphragm is relaxed which decreases the volume of the lung cavity.

• Functional Anatomy of the Respiratory System

  • Active or forced exhalation is achieved by the abdominal and the internal intercostal muscles.
  • During this process, air is forced or exhaled out.
  • During forced exhalation, as when blowing out a candle, the expiratory muscles, including the abdominal muscles and internal intercostal muscles, generate abdominal and thoracic pressure that force air out of the lungs.
  • Forced exhalation is often used as an indicator to measure airway health, as people with obstructive lung diseases (such as emphysema, asthma, and bronchitis) will not be able to actively exhale as much as a healthy person because of obstruction in the conducting zones from inhlation, or from a loss of elastic recoil of the lungs.

• Amphibian and Bird Respiratory Systems

  • Oxygenated air, taken in during inhalation, diffuses across the surface of the lungs into the bloodstream, and carbon dioxide diffuses from the blood into the lungs, and is then expelled during exhalation.
  • This directionality of airflow requires two cycles of air intake and exhalation to completely get the air out of the lungs.
  • The process of inhalation and exhalation in birds.

• Heart Murmurs

  • Interventions such as inhalation and exhalation may lead to changes in murmur sounds.
  • With exhalation, the opposite haemodynamic changes occur.
  • This means that left-sided murmurs generally increase in intensity with exhalation.
  • Abrupt standing or squatting may cause changes in murmur sounds, as does the valsalva maneuver, a forceful attempted exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose while pressing out as if blowing up a balloon.