M********r
发帖数: 179 | 1 问了几个地方，都觉得a 和e 都对，不知道是不是落下了什么重要的concept.
During an experiment, the following data are obtained from an anesthetized
dog:
Mean glomerular capillary hydrostatic pressure 45mmHg
Mean Bowman space hydrostatic pressure 12mm Hg
Mean glomerular capillary oncotic presure 23mmHg
Mean bowman space ontotic pressure 0mm Hg
Coefficient of filtration 3.0ml/
min mmHg
Renal blood flow 200ml/
min
Hematocrit 40%
Filtration fraction 25%
An intravenous infusion of angiotensin II is administered for 60 minutes.
Which of the following is most likely
in this animal after the infusion?
a. increased filtration fraction.
b. increased HPbs
c. increased Kf
d. decreased mean pie GC
e. decreased renal blood flow
I think a and e are both right(although it's not possible). but the right
answer is a not e. I think AgII constrict
the efferent arterial, decrease blood flow, increased GFR thus increased FF.
What's the concept here? Did I
miss something important? |
N***a
发帖数: 149 | 2 这题我考前讨论了一下。我是直接就选A了，根本没有想到E。
后来另一位朋友说E 也可以，我觉得在FA上说的是血浆RPF，不是全血的RBF，是不是就
有这个区别？
后来我们的结论是凡是有直接的答案的，就别选那些有可能正确的。 |
M********r
发帖数: 179 | 3 谢谢，及使是rpf好像也是对的，因为rpf=rbf/1-hct， 而hct是不变的。
就按你说的原则了，觉得你99没悬念。 |
s********o
发帖数: 3319 | 4 这道题答案是A。
E不对，实验的对象是一条狗，在活体里，肾脏的血流是自身调节，在一定范围内肾脏
血流不变。如果是切下的一根血管，你的理解就是对的。
一家之言 |
M********r
发帖数: 179 | 5 版主说的很有道理，赞扎实的基础！！！
等我回家后好好翻书研究一下再发上来。 |
M********r
发帖数: 179 | 6 Scorpion I agree with you now. Kidney is one of the pivotal organs that
follow autoregulation.
Within the range 80-200mmhg，it regulate afferent arteriol by two potential
mechanisms: myogenic and tubuloglomerular feedback. So even though AgII
constrict efferent ateriol, the renal blood flow would be largely unchanged.
I would haven been missed an important point if I didn't ask you guys...
Thanks so much for discussions from all, you guys rock! |
w********7
发帖数: 46 | 7 赞！讨论区的力量是无穷的！
还可以发散一下：体内哪些器官是autoregulation? |
