Today was a long, full day, but it was great. We started out with a seminar about kidney cell membrane channels called aquaporins. These are proteins that make little passages through the membranes of certain renal cells so that water can get through. It's a really neat system that allows the kidney to make your urine concentrated or dilute as needed. There is a hormone called ADH that is responsible for regulating the aquaporins. If you drink a bunch of water and want to get rid of it, then you don't produce much ADH, and the aquaporins aren't inserted into the renal cell membranes. That means the water can't get back into the cells. So it stays in the urinary system, and you wind up making a bunch of dilute urine and hitting the bathroom a lot. But if you're dehydrated and you need to retain more water, then the brain will release ADH into the blood. It goes to the kidneys and stimulates the cells to insert the aquaporins into their membranes. The water flows through the channels out of your urinary system and back into your blood, and you make concentrated urine. Cool!
We finished our PBL case today. Our regular tutor was back, so we were back to our normal rambunctious selves. The presentations were great as usual, and we did a half-hearted concept map in about five minutes. This led to a dicussion about whether we should even be doing concept maps. We decided that we didn't really want to do a concept map because we usually don't find it too useful. I am ok with that, but I was just worried that maybe the course director would not go for that. We were told that it is not actually a requirement for us to do concept maps, so we don't have to do them if we would rather not. On that happy note, we left it where we would do one if someone wanted to do it, and otherwise we'd skip them.
Our POD seminar today was really awesome. The speaker was a PhD who studies angiotensin converting enzyme, or ACE. If you've ever heard of ACE inhibitors, which are given to people with high blood pressure, this is the enzyme that they inhibit. It basically is involved in a pathway that causes the body to retain sodium and water and therefore increases blood volume and blood pressure. Anyway, this speaker was studying different forms of the enzyme. It turns out that for some unknown reason, men make a special form of ACE in their sperm cells and nowhere else. Women do not make the special form at all. So naturally, the question was what the special form in sperm does. It seems to be involved with sperm development. Mice who lacked it were infertile because their sperm were not able to penetrate an ovum. The subject itself wasn't what made the talk so good though. The speaker was just really dynamic and did a great job of getting us involved and talking about what hypotheses we would propose and how we would go about testing them. I wish that all seminars could be like this.
In the afternoon, I volunteered at CHI (the CCLCM student-run free clinic). Today was the last day of the semester for CHI, and it was absolutely insane. First of all, only about half of the normal number of student volunteers showed up, so we only had one person working per table instead of two. That meant we were working extra hard. I was doing the cholesterol and glucose tests, and about an hour into it I ran out of strips. (I had already started out not having any band-aids, but unlike the strips, those you can live without.) We have a second machine that can do glucose readouts only, so I started just doing those. But the people were pretty upset. They wanted their cholesterol read! I hadn't ever been in charge of doing cholesterol and glucose readings, so I tried it on myself first to make sure I could do it. The hardest part is getting enough blood out of some people's fingers. You have to kind of milk the finger, where you push the blood up from the bottom to the tip, and get a nice drop to come out. Then you can fill the capillary tube and add it to the strip in the machine. I got to where I could do it pretty quickly on most people. But whenever I'd get an older lady with skinny, cold fingers, I knew I was in for a workout to get any blood. On top of all that craziness, the CCF marketing people decided to show up today to film us for some promotion they're doing about people at CCF who volunteer in the community. They took footage of us doing all of the tests and also interviewed a few students about why we volunteer. So it was absolute pandemonium, but I had a fantastic time.
Now I am getting ready to go out with some friends for Indian food. Happy Hanukkah to my Jewish readers. :-)