Max Roberts asked:
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.
Can you help?
Love the show
Max from Sydney
We posed this question to Dr Suzy Lishman...
Suzy - There is a tube connecting the lungs to the mouth and thatís called the trachea. Itís the one you can feel - if you just feel the front of your throat just under the Adamís apple, thatís the trachea. Thatís lined by mucous membranes, the epithelial cells that produce mucous which is a thick liquid that forms a phlegm. It has several functions; itís 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. So they get stuck in this sticky mucous 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 mucous. When you're fit and healthy, the mucous 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.