Editing Lung (section)

=== Other ===
In addition to their function in respiration, the lungs have a number of other functions. They are involved in maintaining [[homeostasis]], helping in the regulation of [[blood pressure]] as part of the [[renin–angiotensin system]]. The [[endothelium|inner lining]] of the blood vessels secretes [[angiotensin-converting enzyme]] (ACE) an [[enzyme]] that [[catalysis|catalyses]] the conversion of [[angiotensin I]] to [[angiotensin II]].<ref name=boron>{{cite book |author=Walter F. Boron |title=Medical Physiology: A Cellular And Molecular Approach |publisher=Elsevier/Saunders |year=2004 |isbn=978-1-4160-2328-9 |page=605}}</ref> The lungs are involved in the blood's [[acid–base homeostasis]] by expelling [[carbon dioxide]] when breathing.<ref name="Levitzky2013_1"/><ref name="PatientInfo">{{cite web|last1=Hoad-Robson|first1=Rachel|first2=Tim |last2=Kenny|title=The Lungs and Respiratory Tract|url=http://patient.info/health/the-lungs-and-respiratory-tract|website=Patient.info|publisher=[[Patient UK]]|access-date=11 February 2016|archive-url=https://web.archive.org/web/20150915174801/http://patient.info/health/the-lungs-and-respiratory-tract|archive-date=15 September 2015}}</ref>

The lungs also serve a protective role. Several blood-borne substances, such as a few types of [[prostaglandin]]s, [[leukotrienes]], [[serotonin]] and [[bradykinin]], are excreted through the lungs.<ref name=boron /> Drugs and other substances can be absorbed, modified or excreted in the lungs.<ref name=Levitzky2013_1 /><ref name="Smyth">{{cite book|last1=Smyth|first1=Hugh D.C.|title=Controlled pulmonary drug delivery|date=2011|publisher=Springer|location=New York|isbn=978-1-4419-9744-9|chapter=Chapter 2}}</ref> The lungs filter out small [[thrombus|blood clots]] from [[vein]]s and prevent them from entering [[artery|arteries]] and causing [[stroke]]s.<ref name=PatientInfo />

The lungs also play a pivotal role in [[speech]] by providing air and airflow for the creation of vocal sounds,<ref name=Levitzky2013_1 /><ref>{{cite web|last1=Mannell|first1=Robert|title=Introduction to Speech Production|url=http://clas.mq.edu.au/speech/phonetics/phonetics/introduction/|website=Macquarie University|access-date=8 February 2016}}</ref> and other [[paralanguage]] [[Paralanguage#Specific forms of paralinguistic respiration|communications]] such as [[sighing|sighs]] and [[gasp]]s.

Research suggests a role of the lungs in the production of blood platelets.<ref>{{Cite web | url=https://www.nih.gov/news-events/nih-research-matters/overlooked-role-lungs-blood-formation | title=An overlooked role for lungs in blood formation| date=2017-04-03}}</ref>