RO apologizes.... he rewrote the lab handout, but...I don't have any handout at all, so I'm totally screwed. We *do* have to do a lab report...due 2/24/97, not the date given in the handout. we'll be doing experiments on ourselves. the groups are assigned so there's an equal distribution in each group. 9 setups available. 5 with exercycles, 4 with spirometers. there will be 5 people on the exercycles who then want to do spirometers, but there are only 4 spirometers, so they can either wait, or split up and join the four other groups. it's like musical chairs. this is a flow problem ;) in part A: working with spirometer we'll learn that you need to minimize dead space, that it's uncomfortable to breathe CO2, you don't want to use long tubes with respirators or anesthesia machines. It is not uncomfortable to breathe low [O2] in fact, it's usually a euphoric experience. but it IS dangerous! lab reports are not graded, - you get a 0 for not handing it in, or a 1 for handing it in. they don't care what your Vt or max volume is - be careful. those of us with pulmonary disabilities are not supposed to do this anyway. [yippee! i was just thinking how these tests are going to make me wheeze] make sure to use filters. you attach yourself with the filter and mouthpiece and noseclip to the apparatus. realize that volume measurements are not totally accurate for lung volume per se, because it is dependent on strength of respiratory muscles. /\ / \ /\/\/\/\/\ <- Vt / \ <--inspiratory reserve vol---- \ /<-expiratory \ / reserve vol. residual volume: the amount you can't get out of lungs. seals don't really have one, their chest wall is so compliant vital capacity: largest amount you can get in or out: Vt, irV, erV functional residual capacity: volume left in lung at end of normal expiration: includes erV + rV note: irV doesn't include Vt - you need to subtract Vt from max. maximum breathing capacity: even very fit people - world class athletes - don't really train respiratory muscles. max breathing capacity is usually very fatiguing. brings lots of oxygen into lung, but doesn't add extra to blood, which is already saturated- so it's very costly, energy wise. very tiring. you need to do this test while standing because sitting restricts max breathing capacity. increasing resistance (changing tube) should change results, if you are truly breathing at max breathing capacity. you're also supposed to see if frequency changes when you breathe through narrow tubes. then you repeat with rib belt on. re: waiting ten min bet tests: not necessary for max breathing capacity test. need same person to do control and changes in resistance, btw. but doesn't have to be same person who does lung volume et al. part a: RO part b: dr kubin b; exercycles. you're asked to exercise at 3 metabolic rates: resting, moderate, rapid. [some graph on the board showing neural and humoral control.] exercycle...someone will sit on there and will breathe different gas mixtures. do not exercise while breathing CO2, for example...will have awful headache and will slobber. doesn't matter what order you breathe the gases in. someone MUST know which gas is being breathed, however. when breathing room air, that's 0% CO2 and 21% O2 so that's a point on the graph. will be also breathing 0, 5 and 8% CO2 until reach steady state and see how ventilation changes. add'l exercise: four breaths pure nitrogen: will get very quick increase in ventilation. then you graph results - p 4 has graphs. p 5 discussion only. one of most important equation to learn: amount = concentration * volume. [i'm confused about how to do this a) with no handout and b) without *doing* it. I guess i have to use someone else's results or something.] N2 amt = N2 amt .8 * FRC = .4 (FRC + 2 liters) solve for FRC? measure FRC? it's a matter of keeping track: what goes in and what goes out and what you're using up. here the AMOUNT is the same, but the CONCENTRATION is different. the AMOUNT of nitrogen is being diluted. report due 2/24