Inhalation (also known as inspiration) is the movement of air from the external environment, through the air ways, and into the alveoli.

Inhalation begins with the onset of contraction of the diaphragm, which results in expansion of the intrapleural space and an increase in negative pressure according to Boyle's Law. This negative pressure generates airflow because of the pressure difference between the atmosphere and alveolus. Air enters, inflating the lung through either the nose or the mouth into the pharynx (throat) and trachea before entering the alveoli.

Other muscles that can be involved in inhalation include:[1]


Hyperaeration or hyperinflation is where the lung volume is abnormally increased, with increased filling of the alveoli. This results in an increased radiolucency on X-ray, a reduction in lung markings and depression of the diaphragm. It may occur in partial obstruction of a large airway, as in e.g. congenital lobar emphysema, bronchial atresia and mucous plugs in asthma.[2]

It causes one form of overexpansion of the lung. Overexpansion, however, can also be caused by increase in lung mass itself.

See also


  1. ^ Physiology at MCG 4/4ch2/s4ch2_10[dead link]
  2. ^ "Hyperinflation". Retrieved June 5, 2009.

Wikimedia Foundation. 2010.


Look at other dictionaries:

  • Inhalation — Inhalation …   Deutsch Wörterbuch

  • inhalation — [ inalasjɔ̃ ] n. f. • 1760; bas lat. inhalatio ♦ Méd. Absorption par les voies respiratoires (de gaz, de vapeurs). ⇒ aspiration, inspiration, respiration. Inhalation d éther, de chloroforme, en vue de provoquer l anesthésie. L inhalation de… …   Encyclopédie Universelle

  • Inhalation — In ha*la tion, n. [Cf. F. inhalation.] The act of inhaling; also, that which is inhaled. [1913 Webster] …   The Collaborative International Dictionary of English

  • Inhalation — (v. lat.), 1) das Einathmen; 2) künstliches Einathmen von Dämpfen, Gasarten etc. zu einem Heilzweck (Inhalationscur); 3) das Vermögen der Haut, auch der Lungenoberfläche (bei Pflanzen der Blätter), luftartige Stoffe, bes. Feuchtigkeiten, in… …   Pierer's Universal-Lexikon

  • Inhalation — (lat.), Einatmung; besonders von Dämpfen und Gasen (z. B. Sauerstoff) zu therapeutischen Zwecken …   Meyers Großes Konversations-Lexikon

  • Inhalation — (lat.), Einatmung. Inhalationskur, Inhalationstherapie, methodische Einatmung von Salzen, Arzneistoffen, auch Gasen, entweder unmittelbar im Dunst von Gradierwerken, Gasanstalten, Räucherungen, oder unter Anwendung von Zerstäubungsapparaten, die… …   Kleines Konversations-Lexikon

  • Inhalation — Inhalation, lat. dtsch., Einhauchung; Einathmung …   Herders Conversations-Lexikon

  • inhalation — 1620s, noun of action from pp. stem of L. inhalare (see INHALE (Cf. inhale)) …   Etymology dictionary

  • inhalation — [in΄hə lā′shən] n. [< pp. of L inhalare] 1. the act of inhaling 2. INHALANT …   English World dictionary

  • inhalation — [[t]ɪnhəle͟ɪʃ(ə)n[/t]] inhalations 1) N VAR Inhalation is the process or act of breathing in, taking air and sometimes other substances into your lungs. [FORMAL] ...a complete cycle of inhalation and exhalation... Passengers suffering from smoke… …   English dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.