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Life Sciences => Physiology & Medicine => Topic started by: thedoc on 20/10/2013 10:14:03

Title: Where does phlegm come from?
Post by: thedoc on 20/10/2013 10:14:03

I've been a bit sick lately, and I've been wondering where all the yellow phlegm I've been coughing up comes from.
I understand that there's a tube connecting my lungs with my mouth, but I don't see where so much phlegm can be held!
Asked by Max Roberts


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Title: Where does phlegm come from?
Post by: thedoc on 20/10/2013 10:14:03

We answered this question on the show...

We posed this question to Dr Suzy Lishman...
Suzy -   There is a tube connecting the lungs to the mouth and that’s called the trachea.  It’s the [img float=right]/forum/copies/RTEmagicC_nose_blow_jpg_02.jpg.jpg[/img][/b]one you can feel - if you just feel the front of your throat just under the Adam’s apple, that’s the trachea.  That’s lined by mucous membranes, the epithelial cells that produce mucus, which is a thick liquid that forms a phlegm. 
It has several functions; it’s partly a lubricant, so it stops the airways from drying out when you breath dry air in and out, and it also helps get rid of bacteria and things that you really don't want to have down in your lungs.  They get stuck in this sticky mucus that lines the airways and then it can be coughed up, and it keep it away from the lungs. 
What happens when you get a cold is, in reaction to the extra irritation of your airways, these epithelial cells produce more and more mucus.  When you're fit and healthy, the mucus is normally clear and white, but if you get an infection, it can go yellow or even green, as you cough up all the bacteria and the dead cells that your lungs don't want.

Title: Re: Where does phlegm come from?
Post by: Pmb on 22/10/2013 01:49:25

I get mine at phlegm are us. :D (Sorry, but I'm in a fairly jocular mood).  ;D

Title: Re: Where does phlegm come from?
Post by: healthresearch on 02/11/2013 10:22:43

When your lower airways (trachea, bronchi or lung) get inflamed they can be constantly producing phlegm, so when you cough up a certain amount, the new one will be produced. It's not that all the phlegm has to be in the airways at a certain moment.