# Inhalation > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Inhalation > Markdown URL: https://mediated.wiki/source/Inhalation.md > Source: https://en.wikipedia.org/wiki/Inhalation > Source revision: 1344343677 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{short description|Flow of the respiratory current into an organism}} {{More citations needed|date=March 2020}} {{redirect|Inhale|the 2013 Marsheaux album|Inhale (album)}} thumb|Diagram showing inhalation '''Inhalation''' (or '''inspiration''') happens when air or other gases enter the lungs. == Inhalation of air == Inhalation of air, as part of the cycle of [breathing](/source/breathing), is a vital process for all human life. The process is autonomic (though there are exceptions in some disease states) and does not need conscious [control](/source/Control_of_ventilation) or effort. However, breathing can be consciously controlled or interrupted (within limits). Breathing allows oxygen (which humans and a lot of other species need for survival) to enter the lungs, from where it can be absorbed into the bloodstream. == Other substances – accidental == Examples of accidental inhalation includes inhalation of water (e.g. in drowning), smoke, food, vomitus and less common foreign substances{{Cite journal|last2=Lauriello|first2=M|last3=Bellussi|first3=L|last4=Passali|first4=GC|last5=Passali|first5=FM|last6=Gregori|first6=D|date=2010|title=Foreign body inhalation in children: an update|pmc=2881610|journal=Acta Otorhinolaryngol Ital|pmid=20559470|last1=Passàli|first1=D|volume=30|issue=1|pages=27–32}} (e.g. tooth fragments, coins, batteries, small toy parts, needles). == Other substances – deliberate == === Recreational use === [Nitrous oxide](/source/Nitrous_oxide) ("laughing gas") has been [used recreationally since 1899](/source/Recreational_use_of_nitrous_oxide) for its ability to induce [euphoria](/source/euphoria), [hallucinogenic](/source/hallucinogenic) states and [relaxation](/source/Relaxation_(psychology)), and is legal in some countries. [Helium](/source/Helium) can be inhaled to give the voice a reedy, duck-like quality, but this can be dangerous as the gas is an [asphyxiant](/source/asphyxiant_gas) and displaces the oxygen needed for normal respiration.{{Cite journal| title = Suicidal asphyxiation with helium: Report of three cases Suizid mit Helium Gas: Bericht über drei Fälle| journal = Wiener Klinische Wochenschrift| volume = 119|issue =9–10|date = 2007|doi = 10.1007/s00508-007-0785-4|author = Grassberger, Martin|author2 = Krauskopf, Astrid |pages = 323–325 |language=de, en| pmid = 17571238|s2cid = 22894287}} Various illegal gaseous, vapourised or aerosolized [recreational drugs](/source/recreational_drugs) exist, and are classed as [inhalant](/source/inhalant)s. === Medical use === ==== Diagnostic ==== Various specialized investigations use the inhalation of known substances for diagnostic purposes. Examples include [pulmonary function testing](/source/pulmonary_function_testing) (e.g. [nitrogen washout](/source/nitrogen_washout) test, [diffusion capacity](/source/Diffusing_capacity) testing ([carbon monoxide](/source/carbon_monoxide), [helium](/source/helium), [methane](/source/methane))) and [diagnostic radiology](/source/diagnostic_radiology) (e.g. [radioactive xenon isotopes](/source/Isotopes_of_xenon)). ==== Therapeutic ==== Gases and other drugs used in anaesthesia include oxygen, nitrous oxide, helium, xenon, [volatile anaesthetic agents](/source/Inhalational_anaesthetic). Medication for [asthma](/source/asthma), croup, cystic fibrosis and some other conditions. == Mechanism == Inhalation begins with the contraction of the muscles attached to the rib cage; this causes an expansion in the chest cavity. Then takes place the onset of contraction of the [thoracic diaphragm](/source/thoracic_diaphragm), which results in expansion of the [intrapleural space](/source/intrapleural_space) and an increase in negative pressure according to [Boyle's law](/source/Boyle's_law). This negative pressure generates airflow because of the pressure difference between the atmosphere and alveolus. The inflow of air into the lungs occurs via the [respiratory airways](/source/respiratory_airways). In health, these airways [begin with the nose](/source/Obligate_nasal_breathing).{{cite web |url=https://health.clevelandclinic.org/breathe-mouth-nose/ |title=Should You Breathe Through Your Mouth or Your Nose? |access-date=2020-06-28 |last=Turowski |first=Jason |date=2016-04-29 |publisher=[Cleveland Clinic](/source/Cleveland_Clinic) }}{{cite web|title=Your Nose, the Guardian of Your Lungs|url=https://www.bmc.org/otolaryngology-head-neck-surgery/resources/your-nose-guardian-your-lungs|access-date=2020-06-29|publisher=[Boston Medical Center](/source/Boston_Medical_Center)}} It is possible to begin with the mouth, which is the backup breathing system. However, chronic [mouth breathing](/source/mouth_breathing) leads to, or is a sign of, illness, and there is no mucus in the mouth to trap unwanted substances unlike the nostrils.{{cite web |url=https://www.nbcnews.com/healthmain/mouth-breathing-gross-harmful-your-health-1C6437430 |title='Mouth-breathing' gross, harmful to your health |access-date=2020-06-28 |last=Dahl |first=Melissa |date=2011-01-11 |publisher=NBC News }}{{cite web |url=https://www.journal-imab-bg.org/issues-2018/issue1/JofIMAB-2018-24-1p1878-1882.pdf |title=THE ROLE OF MOUTH BREATHING ON DENTITION DEVELOPMENT AND FORMATION |access-date=2020-05-31 |last=Valcheva |first=Zornitsa |date=January 2018 |publisher=Journal of IMAB }}{{cite web |url=https://www.npr.org/transcripts/862963172 |title=How The 'Lost Art' Of Breathing Can Impact Sleep And Resilience |access-date=2020-06-23 |last=Gross |first=Terry |date=2020-05-27 |publisher=[National Public Radio (NPR)](/source/NPR)/[Fresh Air](/source/Fresh_Air) }} They end in the microscopic dead-end sacs ([alveoli](/source/Pulmonary_alveolus)) always opened, though the diameters of the various sections can be changed by the [sympathetic](/source/Sympathetic_nervous_system) and [parasympathetic nervous system](/source/parasympathetic_nervous_system)s. The alveolar air pressure is therefore always close to atmospheric air pressure (about 100 [kPa](/source/Pascal_(unit)) at sea level) at rest, with the pressure gradients that cause air to move in and out of the lungs during breathing rarely exceeding 2–3 kPa.{{cite journal |last1=Koen |first1=Chrisvan L. |last2=Koeslag |first2=Johan H. | title=On the stability of subatmospheric intrapleural and intracranial pressures |journal= News in Physiological Sciences | date=1995 |volume=10 |issue=4 |pages=176–178 |doi=10.1152/physiologyonline.1995.10.4.176}}{{cite book |last1=West |first1=J.B. |title=Respiratory physiology: the essentials. |location=Baltimore |publisher=Williams & Wilkins |date=1985| pages= 21–30, 84–84, 98–101 }} Other muscles that can be involved in inhalation include:{{cite book| title= Essentials of Human Physiology| first= Thomas M. |last= Nosek| chapter=Section 4/4ch2/s4ch2_10 |chapter-url=http://humanphysiology.tuars.com/program/section4/4ch2/s4ch2_10.htm |archive-url=https://web.archive.org/web/20160324124828/http://humanphysiology.tuars.com/program/section4/4ch2/s4ch2_10.htm|archive-date=2016-03-24}} * [External intercostal muscles](/source/External_intercostal_muscles) * [Scalene muscles](/source/Scalene_muscles) * [Sternocleidomastoid muscle](/source/Sternocleidomastoid_muscle) * [Trapezius muscle](/source/Trapezius_muscle) ==Hyperinflation== {{For-multi|another similar term|Dynamic hyperinflation|the Economics term|Hyperinflation}} ''Hyperinflation'' or ''hyperaeration'' is where the lung volume is abnormally increased, with increased filling of the alveoli. This results in an increased [radiolucency](/source/radiodensity) 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](/source/congenital_lobar_emphysema), bronchial [atresia](/source/atresia) and mucus plugs in [asthma](/source/asthma).{{cite web|url=http://www.medcyclopaedia.com/library/topics/volume_vii/h/hyperinflation.aspx|archive-url=https://archive.today/20111208222639/http://www.medcyclopaedia.com/library/topics/volume_vii/h/hyperinflation.aspx|url-status=dead|archive-date=2011-12-08|title=Hyperinflation|publisher=[GE](/source/General_Electric)|work=Medcyclopaedia}} ==Yoga== Yogis such as [B. K. S. Iyengar](/source/B._K._S._Iyengar) advocate both [inhaling and exhaling through the nose](/source/Obligate_nasal_breathing) in the practice of [yoga](/source/yoga), rather than inhaling through the nose and [exhaling through the mouth](/source/Mouth_breathing).{{cite web |url=https://www.yogajournal.com/practice/take-a-breath |title=Q&A: Is Mouth Breathing OK in Yoga? |access-date=2020-06-26 |date=2017-04-12 |publisher=[Yoga Journal](/source/Yoga_Journal) }}{{cite web |url=https://www.dummies.com/health/exercise/yoga/yogic-breathing-tips-for-breathing-through-your-nose-most-of-the-time/ |title=Yogic Breathing: Tips for Breathing through Your Nose (Most of the Time) |access-date=2020-06-26 |last=Payne |first=Larry |publisher=[Yoga For Dummies, 3rd Edition](/source/For_Dummies) }}{{cite web |url=https://www.himalayaninstitute.org/wisdom-library/yogic-breathing-study-guide/ |title=Yogic Breathing: A Study Guide |access-date=2020-06-26 |last=Himalayan Institute Core Faculty |first=Himalayan Institute Core Faculty |date=2017-07-13 |publisher=[Himalayan Institute of Yoga Science and Philosophy](/source/Himalayan_Institute_of_Yoga_Science_and_Philosophy) }} They tell their students that the "nose is for breathing, the mouth is for eating."{{cite book |url=https://books.google.com/books?id=QPk_nshsngoC&q=%22the+nose+is+for+breathing%2C+the+mouth+is+for+eating%22+yoga&pg=RA1-PA11 |title=Yoga Sparks |access-date=2020-05-31 |last=Krucoff |first=Carol |date=2013 |publisher=New Harbinger Publications |isbn=9781608827022 }}{{cite book |url=https://books.google.com/books?id=fEm6XnTajm0C&q=%22the+nose+is+for+breathing%2C+the+mouth+is+for+eating%22+yoga&pg=PA108 |title=Eat and Run |access-date=2020-05-31 |last=Jurek |first=Scott |date=2012 |publisher=Houghton Mifflin |isbn=978-0547569659 }} ==See also== {{Wiktionary|inhalation|sniffing}} * [Exhalation](/source/Exhalation) * [Inhalant](/source/Inhalant) – psychoactive drugs consumed through inhalation * [List of terms of lung size and activity](/source/List_of_terms_of_lung_size_and_activity) * [Mouth breathing](/source/Mouth_breathing) * [Obligate nasal breathing](/source/Obligate_nasal_breathing) * [Respiratory system](/source/Respiratory_system) * [Smoking](/source/Smoking) - a specific inhalation route * [Breathing](/source/Breathing) * [Work of breathing](/source/Work_of_breathing) ==Further reading== * {{Cite book|title=[Breath: The New Science of a Lost Art](/source/Breath%3A_The_New_Science_of_a_Lost_Art) |last=Nestor|first=James|publisher=Riverhead Books |year=2020|isbn= 978-0735213616 }} ==References== {{reflist}} {{Dosage forms}} {{Respiratory physiology}} Category:Respiration Category:Respiratory physiology --- Adapted from the Wikipedia article [Inhalation](https://en.wikipedia.org/wiki/Inhalation) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Inhalation?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.