The breathing cycle, also known as the respiratory cycle, is a continuous process involving two main phases: inspiration (inhaling) and expiration (exhaling).
Inspiration (Inhalation)
Inspiration is the active phase where air flows into the lungs. This is primarily driven by the contraction of the diaphragm and intercostal muscles, which increases the volume of the chest cavity, creating lower pressure inside the lungs and drawing air in. [The first phase is the inspiration phase. Inspiration allows air to flow into the lungs.](Reference: MedlinePlus Medical Encyclopedia Image)
Expiration (Exhalation)
Expiration is typically a passive process. The relaxation of the diaphragm and intercostal muscles reduces the chest cavity volume, increasing the pressure inside the lungs, causing air to flow out. [The second phase is expiration. Expiration involves gases leaving the lungs.](Reference: MedlinePlus Medical Encyclopedia Image) [A respiratory cycle is one sequence of inspiration and expiration.](Reference: Lumen Learning) The main purpose of this cycle is to exchange gases: bringing in fresh oxygen and expelling carbon dioxide. [The main purpose of the respiratory cycle is to bring fresh oxygen into the body and to expel…](Reference: Osmosis)
Active Cycle of Breathing Technique (ACBT)
While the basic breathing cycle is passive, techniques like the Active Cycle of Breathing Technique (ACBT) involve active phases to aid in clearing mucus from the lungs. ACBT combines different breathing exercises to improve airway clearance. [Active cycle of breathing technique (ACBT) combines different breathing techniques that help clear mucus from the lungs in three phases.](Reference: Cystic Fibrosis Foundation) [The Active Cycle of Breathing Techniques (ACBT) is an active breathing technique performed by the patient and can be used to…](Reference: Physiopedia) This technique is sometimes used for individuals with conditions like cystic fibrosis. [The active cycle of breathing technique (also known as ACBT) is an airway clearance method that uses a cycle of techniques to loosen airway secretions including…](Reference: PMC) However, more research is needed to definitively compare its effectiveness against other methods. [There is insufficient evidence to support or reject the use of the active cycle of breathing technique over any other airway clearance…](Reference: PubMed)
