Guest BCgirl Posted August 22, 2001 Report Share Posted August 22, 2001 I had that question as well. I chose the salt water fish. I understand the reasoning people have for choosing fresh water fish, but on the PR board someone posted a link to a McMaster (I think it was a McMaster) web page that says marine nephrons lack a loop of henle, so I guess the salt water answer is right. Link to comment Share on other sites More sharing options...
Guest Ian Wong Posted August 22, 2001 Report Share Posted August 22, 2001 Here's my guess. I vote for salt water. As far as I remember, the LoH is impermeable to water, but reabsorbs a large amount of salt. As a result, after leaving the LoH, the fluid is more dilute than it was before. So, it seems like the LoH would be most useful for a creature that was trying to lose dilute water. This to me sounds like a water-losing proposition, where you would excrete more water than ions for each given amount of filtration and passage through the LoH. Therefore, I'd think the fresh-water fish would be the ones to use the LoH, and salt-water fish would try to excrete a larger fraction of ionic wastes relative to the water (ie. they would want to excrete a more concentrated urine). I figure I've got a 50% chance of being right. In humans (and fish too, most likely), all of this stuff is complicated by other things like aldosterone, ADH, ANP, oncotic pressure due to liver protein synthesis, blood pressure, and a bunch of other factors. It also doesn't help that Physiology never was my strong suit; didn't have any real exposure to it in undergrad. Ian UBC, Med 3 Link to comment Share on other sites More sharing options...
Guest Kirsteen Posted August 23, 2001 Report Share Posted August 23, 2001 Hey there guys, As much as I've been trying to replace extraneous MCAT factoids with admissions activities, if I recall correctly you're half right. That LoH does love leeching out sodium, but only on the ascent; the descent is a bastion of water flow out of the tubule. So I'd be all with you there if it was only a vehicle for sodium, but alas, I think that's only half the story. Hence, if someone could fill in some gaps re: the content of the actual question, then we could put our brains to collective use! Ciao, Kirsteen Link to comment Share on other sites More sharing options...
Guest BCgirl Posted August 23, 2001 Report Share Posted August 23, 2001 I think it asked something like: For which organism would it be detrimental to have a loop of Henle: Fresh water fish Salt water fish Desert animal Something else (anyone remember?) I find it odd that people have found info that says both fresh water and salt water fish do not have loops of Henle. Link to comment Share on other sites More sharing options...
Guest Kirsteen Posted August 23, 2001 Report Share Posted August 23, 2001 Hey there BCgirl, I'm pretty sure I recall that there was a bit more detail behind the question, especially pertaining to the environment that the fish was in prior and the one that it would be moving to, without the LoH. No matter, it's been a fun discussion, let's hope we do well, overall. Kirsteen Link to comment Share on other sites More sharing options...
Guest BCgirl Posted August 23, 2001 Report Share Posted August 23, 2001 I don't remember the question saying anything about a prior environment. Anyway, how could they have stated that if some of the answers are fish while the others are land animals? It wasn't just fish. Link to comment Share on other sites More sharing options...
Guest MCATTER Posted August 24, 2001 Report Share Posted August 24, 2001 Hi Guys... Was just reading the posting, and I found that some sections were not properly timed, and especially the bio section she knocked off a couple of mins... !! Also, 5 mins before the Bio section was ending the lady started reading the instructions on how to do the survey, how stupid was that... I thought that was pathetic. Also, the room I was adjacent to a room which had some Holiday Inn employees cleaning up and all I could hear was banging plates (or glasses?), etc.. it was horrible. Did anyone share the same experience? I would really like for someone who had the same experience to write to AAMC, because honestly, I didn't pay 250 some odd dollars for this kind of treatment. Annoyed MCATTER Link to comment Share on other sites More sharing options...
Guest BCgirl Posted August 24, 2001 Report Share Posted August 24, 2001 MCATTER, That sucks. I think if you want to, you should write to the AAMC and complain about that. The address is in the MCAT announcement booklet. Link to comment Share on other sites More sharing options...
Guest Kirsteen Posted August 24, 2001 Report Share Posted August 24, 2001 Hi MCATTER, I think I may have been in the same room as you as I do recall the invigilator beginning to read the survey instructions near the end of bio, plus they actually handed the surveys our during the last part of bio. I can't speak for the timing though: although I was watching my own timer, I took my eyes off it in relief once we were asked to put out pencils down. Another item that I don't know if you'll recall or if it affected you that I felt badly about was during the WS or BS section. A while earlier, a couple of people over on the far right had voiced an opinion about their table, I believe. In any case, during one of the sections two HI dudes came in with a new conference table and placed it in front of this bunch of folk. It wasn't all that near me so I didn't find it all that distracting, but I think it could have taken a concentrated effort for those around the table to keep their mind on their work. Back to contacting the AAMC: does anyone know how reactive they are regarding students who have undergone undue distractions during the test? I had encountered some annoying distractions last year during VR when I wrote at UT and mentioned it to the invigilator, but it didn't seem that there was much they could do. The noises really upset my concentration at the time and subsequently helped to raise my anxiety level during VR. I didn't write to the AAMC regarding this as I received the impression, via the invigilator, that I was relatively powerless. Remedy for this year: made sure that I placed my MCAT study desk right in front of an open window overlooking the intersection at Avenue and Yorkville as the mega-horsepower Ferraris and Harleys (many conspicuously missing silencers) tooled by. Made one hell of a difference this time around as I didn't need to use some of the dampening devices that were ported by some folk in the room--did you guys see the person who brought the airport runway ear protectors? That's imagination. FYI, in case you find yourself in this scenario in October when the results come rolling in, I do know that the AAMC can be amenable regarding other parts of the exam. A friend of a friend wrote last year's MCAT along with me and scored really well on all the numerical sections, e.g., 11, 12, 13, but scored quite poorly on the WS (L or something along those lines). Given that this WS mark was lower than most school cut-offs, she disgruntledly resubmitted her essays for re-scoring and, voila, they came back much improved. I can't remember her new score exactly, but it ended up being significantly higher than the L and she did manage to secure a place in an out-of-province Canadian school this year. So, if you find yourself in the same spot, it may be worth the risk to send your essays back in for another look. Cheers, Kirsteen Link to comment Share on other sites More sharing options...
Guest JSS02 Posted August 24, 2001 Report Share Posted August 24, 2001 I was sitting on the far right side, just behind those people who had the crappy table. I almost got hit by the new one that was getting carried in =). However, it didn't turn out to be a big distraction... Link to comment Share on other sites More sharing options...
Guest Paregorics Posted October 3, 2001 Report Share Posted October 3, 2001 Did anyone have the VR containing numerous science/natural science passages i.e. formation of stars and galaxies, engineers conception of building an organism, ...I cant remember the rest. My mind has thoughtfully turned off any notions of the mcat. I do remember being strapped for time, but since the last passage (stars and @#%$) was something I had studied in the past I answered the questions with minimal referral to the passage itself. How did the rest of y'all find it? Link to comment Share on other sites More sharing options...
Guest Kirsteen Posted October 3, 2001 Report Share Posted October 3, 2001 Hey there, Can't recall either of those passages, Paregorics. On a related MCAT note though, any of you going through the dreams where you receive your results and they're through the MCAT roof? Ah, what bliss...if it only could become reality! I guess we'll find out in a few short weeks. Good luck all, Kirsteen Link to comment Share on other sites More sharing options...
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