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Expert: Florence M Rollwagen - 8/27/2008


Question
In alveoli, gases can diffuse into living cells if the gases are in liquid solution, so the surface is kept moist. But why cant gases diffuse as gases? Why they need to be in liquid state??

Answer
Hi Pooja:  Thanks for your question.

Actually, it's the cells that have to remain moist to stay alive.  Don't forget, we are all water creatures and live in a watery environment.  Gases certainly can diffuse as gases, but since the cells have to be moist, they diffuse in the liquid.

When you ask:  "Why they need to be in liquid state"  do you mean the gases?  They're not in a liquid state, they are dissolved in the moisture around the alveolar cells.

Skin cells don't have to be kept moist, since they have a dried out layer (keratinized cells) to protect them from dessication.  But gases can't diffuse through those hard cells.  Alveolar cells have no such protection, and have to be moist all the time.

Hope this answer has helped you.  Please write back if you have more questions.

FM Rollwagen, PhD

Biology

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Florence M Rollwagen

Expertise

I can answer questions in biology, microbiology and immunology on the undergraduate or graduate level. I can also address medical and health concerns regarding alternative medicine, autoimmune diseases (lupus, MS) liver disease and intestinal problems.

Experience

I have over 20 years experience in research and teaching at the medical/graduate level, and 5 years teaching college biology and microbiology. My expertise is in microbiology and immunology, specifically the biology of cytokines and soluble immune response modifiers. I also carried out original research in blood substitutes and shock/trauma.

Organizations
American Association of Immunologists (AAI) American Association for the Advancement of Science (AAAS)

Publications
Journal of Experimental Medicine, Journal of Immunology, Cytokine, Shock, Experimental Hematology

Education/Credentials
BS biology 1966 MS biology 1968 PhD immunology 1979

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