Exhalation: Difference between revisions

Latest revision as of 11:34, 15 February 2025

Exhalation[edit]

Diagram of the expiration process

Exhalation, also known as expiration, is the process of expelling air from the lungs through the airways to the external environment. It is a vital part of the respiratory cycle, which includes both inhalation and exhalation.

Physiology of Exhalation[edit]

Exhalation is primarily a passive process that occurs when the diaphragm and intercostal muscles relax. During inhalation, these muscles contract to expand the thoracic cavity, allowing air to flow into the lungs. When these muscles relax, the thoracic cavity decreases in volume, increasing the pressure inside the lungs relative to the outside atmosphere, causing air to flow out.

Muscles Involved[edit]

While exhalation is generally passive, certain conditions require active exhalation, which involves additional muscle groups:

The internal intercostal muscles contract to pull the ribs downward and inward.
The abdominal muscles contract to push the diaphragm upward.

These actions increase the pressure in the thoracic cavity, forcing air out more rapidly.

Control of Exhalation[edit]

The process of exhalation is controlled by the respiratory center in the medulla oblongata and the pons of the brainstem. These centers regulate the rhythm and depth of breathing by sending signals to the respiratory muscles.

Exhalation in Different Conditions[edit]

Exhalation can be affected by various physiological and pathological conditions:

During exercise, the rate and depth of breathing increase, and active exhalation becomes more prominent.
In conditions such as asthma or chronic obstructive pulmonary disease (COPD), exhalation can be impaired due to airway obstruction.

Related Pages[edit]

@@ Line 1: / Line 1: @@
-'''Exhalation''' (or '''expiration''') is the flow of the [[Breathing|breath]] or [[Air|air]] out of an organism. In humans it is the movement of air out of the [[Bronchus|bronchial tubes]], through the [[Airway|airway]], to the external environment during [[Breathing|breathing]].
+== Exhalation ==
-== Process ==
+[[File:Expiration_diagram.svg|thumb|right|Diagram of the expiration process]]
-Exhalation is a passive process due to the [[Elasticity (physics)|elastic properties]] of the [[Lung|lungs]]. During this process, the high pressure air in the lungs is exhaled out of the body leading to a decrease in volume, which leads to an increase in pressure in comparison to the atmosphere. The process of exhaling air out of the lungs is powered by the [[Elasticity (physics)|elastic recoil]] of the lung tissue which is caused by the [[Alveoli|alveolar]] surface tension, and the [[Diaphragm (anatomy)|diaphragm]] relaxing.
-== Role in the respiratory cycle ==
+'''Exhalation''', also known as '''expiration''', is the process of expelling air from the [[lungs]] through the [[airways]] to the external environment. It is a vital part of the [[respiratory cycle]], which includes both inhalation and exhalation.
-The process of exhalation plays a crucial role in the [[Respiratory cycle]]. The process of inhaling air into the lungs is known as [[Inhalation|inhalation]]. The purpose of the respiratory cycle is to exchange oxygen and carbon dioxide between the body and the environment. This exchange process is essential for maintaining the body's [[Acid-base homeostasis|acid-base balance]] and for the process of [[Cellular respiration|cellular respiration]], which generates energy for the body's functions.
-== See also ==
+== Physiology of Exhalation ==
-* [[Inhalation]]
-* [[Breathing]]
+Exhalation is primarily a passive process that occurs when the [[diaphragm]] and [[intercostal muscles]] relax. During inhalation, these muscles contract to expand the [[thoracic cavity]], allowing air to flow into the lungs. When these muscles relax, the thoracic cavity decreases in volume, increasing the pressure inside the lungs relative to the outside atmosphere, causing air to flow out.
-* [[Respiratory cycle]]
-* [[Cellular respiration]]
+=== Muscles Involved ===
-* [[Acid-base homeostasis]]
+While exhalation is generally passive, certain conditions require active exhalation, which involves additional muscle groups:
+* The [[internal intercostal muscles]] contract to pull the ribs downward and inward.
+* The [[abdominal muscles]] contract to push the diaphragm upward.
+These actions increase the pressure in the thoracic cavity, forcing air out more rapidly.
+== Control of Exhalation ==
+The process of exhalation is controlled by the [[respiratory center]] in the [[medulla oblongata]] and the [[pons]] of the [[brainstem]]. These centers regulate the rhythm and depth of breathing by sending signals to the respiratory muscles.
+== Exhalation in Different Conditions ==
+Exhalation can be affected by various physiological and pathological conditions:
+* During [[exercise]], the rate and depth of breathing increase, and active exhalation becomes more prominent.
+* In conditions such as [[asthma]] or [[chronic obstructive pulmonary disease]] (COPD), exhalation can be impaired due to airway obstruction.
-== References ==
+== Related Pages ==
-<references />
-{{stub}}
+* [[Inhalation]]
+* [[Respiratory system]]
+* [[Lung]]
+* [[Diaphragm (anatomy)]]
 [[Category:Respiratory physiology]]
-[[Category:Breathing]]