Respiration Seminar and PBL

Today's seminar was really neat. We went over to the Crile building, which is one of the clinics on campus, and we got to see the effects of breathing a high concentration of carbon dioxide first hand. Three of my classmates and I volunteered to breathe a mixture of gases that contained a high concentration of carbon dioxide. There was plenty of oxygen in there also, but because there are chemical receptors in the brain that specifically detect carbon dioxide, it still makes you start breathing harder and faster when you breathe a gas mixture full of carbon dioxide. Of course, since you're breathing into a bag, that makes the carbon dioxide levels rise even more as you pant away, and things just keep getting worse. This experiment also simulates what it's like to be short of breath. I only did it for about three or four minutes, and it was kind of frightening. You're breathing hard, and it feels like you just can't get enough air. It definitely made a huge impression on all of us, and it also gives me some major sympathy for patients who feel like this all of the time.

We continued on with our PBL case today too. Because of the seminar that we had last Friday about acid/base chemistry, we pretty much figured out what the patient's problem was immediately. This case is also starting to get us into studying the kidneys quite a bit. My next learning objective involves figuring out what the creatinine levels in the blood mean. Our case patient had raised creatinine levels. From what I've read, it seems to mean that her kidneys are not functioning properly. Creatinine is the by-product of another chemical in your muscles called creatine. You make creatinine from creatine whenever you break down muscle mass. The raised creatinine level could happen for a lot of reasons, but I think it's because she's dehydrated. That would mean there would be a lower volume of blood going to the kidneys, and it would cause her creatinine to rise because her kidneys aren't filtering it.

After PBL, I had lunch and went to the gym, and now I'm home to do some studying.