Talk:Pulmonary alveolus

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The contents of the Alveolar cells page were merged into Pulmonary alveolus. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page.

My understanding was that the CO2 exchange was based on sodium bicarbonate and that carbon dioxide does not bind to red blood cells. Perhaps this can be checked and this page updated? CustardJack — Preceding undated comment added 13:06, 8 April 2005 (UTC)[reply]

No, only 70% of CO2 is exchanged to sodium bicarbonate. Roughly 23% binds to hemoglobin. The remaining 7% travels dissolved in the plasma.— Preceding unsigned comment added by Blyndon (talk • contribs) 06:10, 13 May 2005 (UTC)[reply]

Hm. My physiology lecture notes say 10% CO₂ in solution, 85% as bicarbonate and 5% stuck to proteins such as Hb. Orimlig 04:24, 5 December 2006 (UTC)[reply]

Just editing out the blabber by some immature kiddie. Exigence 02:42, 11 April 2007 (UTC)[reply]

guys whats the meaning of gas exchange in plANTS .I seriopusly need your help.. — Preceding unsigned comment added by 168.167.134.115 (talk) 08:14, 31 August 2016 (UTC)[reply]

Is there a disease in which the alveolus don't work because the gas exchange is only one way? It is said it is something irreversible. Is there a name for this disease? Marisol Meyer — Preceding unsigned comment added by 71.136.43.34 (talk) 23:17, 4 December 2005 (UTC)[reply]

When there is fluid or fibrotic tissue in the alveoli the oxygen delivery to the blood will be affected before the removal of carbon dioxide. Thus hypoxemia (low oxygen in the blood) will happen, without significant hypercapnia (high carbon dioxide in the blood). This occurs because carbon dioxide diffuses more rapidly due to a greater gradient. Often the effects of such diseases are most aparent during exercise — Preceding unsigned comment added by 142.231.110.50 (talk) 20:30, 12 May 2006 (UTC)[reply]

I am currenly doing a science test, and one of the questions is "Describe how the alveoli are specialized to help oxygen enter the blood." I don't know the answer! Does anyone know? — Preceding unsigned comment added by 142.59.222.22 (talk) 19:36, 8 March 2006 (UTC)[reply]

Answer: Alveoli have different types of cells that assist with gas exchange. The "type 2" cells produce surfactant which reduces the surface tension in the alveolus, this prevents the alveolus from collapsing and allows the structures to remain patent (open and ready to exchange gas). The other type of cell is type 1 and is a very thin and delicate membrane that provides the interface for gas exchange.— Preceding unsigned comment added by 142.231.110.50 (talk) 20:25, 12 May 2006 (UTC)[reply]

Everyone agrees that the word broncholiotes under 'Chronic bronchitis' is a typing error for bronchiolites? 131.224.251.68 13:44, 24 March 2006 (UTC)[reply]

Looks that way to me. susato 14:46, 26 September 2007 (UTC)[reply]

This looks way too small, if the 0.1 mm (100 micron) radius is correct, the photomicrograph indicates that the walls would be about 10-20 microns thick. Mammalian cells are bigger than 0.2 microns, usually 10-20 microns at least. (Bacterial cells are 1-2 microns in size) Furthermore, the alvelolar walls contain capillaries through which erythrocytes (radius 6-8 microns, thickness 1-2 microns) pass. Please clarify -- Thanks! susato 14:46, 26 September 2007 (UTC)[reply]

Followup: http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Respiratory/respir.htm has some good images and a claim that the alveolar wall is around 2 microns in thickness. susato 15:17, 26 September 2007 (UTC)[reply]

Should this say that:

"The alveoli are found in the respiratory zone of the gasbags" ? —Preceding unsigned comment added by Matronlulu (talk • contribs) 17:37, 11 December 2007 (UTC)[reply]

Could some of the respiratory pages be created in simple english. I'm doung this for a school project, and don't have a clube what half of the terms mean. Or just a section explaining what the alveoli DO...? The ilovebigcats (talk) 12:55, 22 February 2009 (UTC)[reply]

Problem: When i wikipedia "alveolar sac" im redirected to alveolus, however these two are not the same. Dorland's defines alveolus as, "... small polyhedral outpouchings along the walls of the alveolar sacs and alveolar ducts" and therefore "alveolar sac" would consist of the chamber directly preceding the alveolus. —Preceding unsigned comment added by Lasse9477dkimedepauw (talk • contribs) 12:24, 26 March 2010 (UTC)[reply]

With reference to number of alveoli: text books (GCSE/O level textbooks and A level text books) quote a TOTAL of 300-350 million alveoli in both lungs NOT each in lung. Total surface area of 90-100m2 does agree with text books. Just wanted to put forward this point. Maybe someone might clarify. —Preceding unsigned comment added by 85.232.213.63 (talk) 13:22, 13 February 2011 (UTC)[reply]

The source quoted at the point where it is stated that there is a total of 100 m^2 of surface area created by the alveoli relates that there is an approximate surface of 75 m^2. It seems odd to me that the reference actually states another piece of information, especially since 75 m^2 is used just below. I do express my uncertainty at this, I am by no means a doctor or medical student, but this oddity struck me and something seems wrong. Just to be clear: source 5 leads to two pages which relate that the total surface of the alveoli equals about 75 m^2, while it is used to validate the information on the wiki, which states that this surface is 100 m^2. The oddity continues because 75 m^2 is mentioned again about three sentences further on in the text.

Note: I have never contributed to wikipedia before so I am sorry if I have not succesfully followed the code of conduct.

156.83.1.251 (talk) 08:16, 6 August 2012 (UTC)[reply]

You're right; the text should correspond to the reference.

The next reference (75 m^2) links to a creationist advocacy site's review of the text, rather than the textbook's publisher

Further in the text, we have "about 80 square meters," no reference.

Looks like some cleanup is needed.

148.61.78.45 (talk) 12:32, 16 July 2015 (UTC)[reply]

The fact of the matter is that there is no magisterial reference whatsoever deriving the lung total tissue/air area from the alveoli count. The fractally subdivided airways themselves do not present an insignificant surface area that must be taken into account for their contribution to, for example, the extent of any pathological process that might need to be addressed in treatment or theory.

To be topical, Jan. 2 2021, a covid-19 virus can land anywhere along the way from the nasal passages to the bronchi to the alveoli. JohndanR (talk) 18:51, 2 January 2021 (UTC)[reply]

See https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919356/

"Measurements of Deposition, Lung Surface Area and Lung Fluid for Simulation of Inhaled Compounds" 2016

§"Absorption area" JohndanR (talk) 19:05, 2 January 2021 (UTC)[reply]

Better placed as a single article; confusing to have two separate articles Tom (LT) (talk) 19:10, 28 February 2018 (UTC)[reply]

• Support --Iztwoz (talk) 16:14, 3 April 2018 (UTC)[reply]

As indicated by the many entries at Alveolus (disambiguation), this is not the only, or even main, meaning of the word. Therefore those terms should not redirect here. FunkMonk (talk) 11:56, 20 March 2018 (UTC)[reply]

Hello FunkMonk - there is a hatnote on the page to refer to Disambig page for other uses. It may be the most searched for ? --Iztwoz (talk) 14:32, 7 June 2018 (UTC)[reply]

That doesn't explain why those terms should redirect here. FunkMonk (talk) 18:51, 7 June 2018 (UTC)[reply]

FunkMonk Have looked again and tend to agree with you - have changed redirect to the disambiguation page - If alveolus was to redirect to pulmonary alveolus then pulmonary alveolus ought to be the primary topic and named alveolus. However I left alveoli as it's the usual plural? --Iztwoz (talk) 20:22, 22 June 2019 (UTC)[reply]

But have just looked at disambiguation page and there are other terms that use the plural so shall go ahead and change that redirect. best--Iztwoz (talk) 20:25, 22 June 2019 (UTC)[reply]

"They are located sparsely on the respiratory bronchioles, line the walls of the alveolar ducts, and are more numerous in the blind-ended alveolar sacs."

Is this really saying that there are alveoli elsewhere than in the alveolar sacs? If so is there a source for this information? It contradicts what is shown in the diagram, and what every independent source I can find says about the subject, to the extent that I wonder if the sentence has been taken out of context and "they" is not actually supposed to refer to alveoli - for example it would make sense if it was about capillaries. HairyDan (talk) 23:06, 21 March 2020 (UTC)[reply]

Yes, this is saying that there are alveoli elsewhere than in the alveolar sacs. The alveolar sacs are specialized to have tons of alveoli. But alveoli, which are the specialized structures that are responsible for gas exchange, are also located in fewer amounts in the alveolar ducts and even in the respiratory bronchioles. Although I also do not have a source for this, as a pediatrician, I happen to believe this has to be true just because I know that 24-week premature babies do not have air sacs - they barely just have respiratory bronchioles - and it is only because these respiratory bronchioles have a few alveoli that they are able to get enough oxygen and survive if you give them extra oxygen or put them on a ventilator. These respiratory bronchioles then develop alveolar ducts and then after that develop alveolar sacs. We know that respiratory bronchioles must contain alveoli because otherwise, premature babies at 24 weeks would not be able to get any oxygen even if placed on a ventilator.

This article from the British Lung Foundation states that the alveolar sacs form at 32 weeks. https://www.blf.org.uk/support-for-you/how-childrens-lungs-grow Note that this article also seems to confuse alveoli with alveolar air sacs. So you're not the only one that is confused. Even the British Lung Foundation can easily make this mistake. But the alveoli (microscopic structures) are located within the alveolar air sacs (pockets at the end which you can see). This just gives me the idea to add this concept of lung development in here. I think when alveoli form in embryonic development is kind of important on the article of alveoli.

Another piece of evidence that respiratory bronchioles contain at least a few alveoli is the very fact that they are called respiratory bronchioles. These are the only bronchioles (tubes in the lungs) that can actually breathe! They can breathe because they contain alveoli. --Beezer137 (talk) 19:58, 5 April 2020 (UTC)[reply]

Added supporting ref from Structure section.--Iztwoz (talk) 17:39, 11 April 2020 (UTC)[reply]