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Blood flow through the nephron - (Apr/12/2011 )

Good morning! Disclaimer: I am a Liberal Arts student taking required Human Biology course. Not a 'science' person by any stretch of the imagination; I am, however, a very curious person. A recent quiz question, my inquiry to my teacher, and her response finds me still wanting clarification about blood flow through the nephron. This is what I asked my teacher:
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"You asked about the blood flow through the nephron. OK - thanks to Wiley + animated exercises, I had the words "peritubular capillaires" stuck in my brain along with "glomerulus", "afferent and efferent", "Bowman's" and "vasa" something-or-other. After all these, then the filtered wastes and some water go to the tubule (PCT) and then Henle and then DCT..

and this is where I thought (starting at tubule) there was no more blood - it is now called "fluid"...

so... my guessing the correct answer was good for me, but I still woke up thinking about it and wondering if the 'fluid' is really 'fluid' or is it blood? I thought 'fluid' was water and wastes, not blood - hence my confusion at the possible answer choices of your question.

Just what is the 'fluid' that passes through the PCT, etc.? Water and waste products or blood or a bit of both?"
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Forum response and clarification would be greatly appreciated!! It's 2 days after the quiz and I'm still thinking about this, lol!

-mngal-

DCT = Distal Convoluted Tube ?

Or?

Anyway: if there is blood in the tubule, henle, DCT etc.. then there is something wrong. There shouldnt be blood in your urine...

But to be honest, I dont really understand what you are asking ... to me it seems you are mixing up some things.
There is a distinction between the blood flow (arteries etc) and the "urineflow"... I think you are mixing up something here.. The blood never leaves the arteries.

-pito-

pito on Tue Apr 12 15:00:37 2011 said:


DCT = Distal Convoluted Tube ?

Or?

Anyway: if there is blood in the tubule, henle, DCT etc.. then there is something wrong. There shouldnt be blood in your urine...

But to be honest, I dont really understand what you are asking ... to me it seems you are mixing up some things.
There is a distinction between the blood flow (arteries etc) and the "urineflow"... I think you are mixing up something here.. The blood never leaves the arteries.


~~~~~~~~~
Thank you Pito! You did understand even though you thought you didn't, :) From everything I could understand - there is NO blood (not supposed to be) from the PCT onward (that's where the formation of urine starts) so that's why I was confused when her choices were ALL from the PCT onward....

This was the question and her choices:

Which of the following is in the correct order in regard to the flow of blood as it's filtered through a nephron?

1) proximal tube - loop of Henle - distal tube - collecting duct
2) loop of Henle - distal tube - proximal tube - collecting duct
3) proximal tube - distal tube - loop of Henle - collecting duct
4) distal tube - proximal tube - collecting duct - loop of Henle

my confusion arose because - urine formation starts at the proximal tube and there should be NO blood - as you said

Huh.... guess it was just a 'bad' question or I'm too darn literal...IMO, in this instance, there is a distinct difference between "blood" and "fluid".

Thanks ever so much! :)

-mngal-

Either your teacher doesnt understand it, or its a bad question.

The blood doesnt flow in those parts.. it flows next to it (in the vasa recta for example)

Another side note: the vasa recta and loop of henle: they are not like in most pictures.. In reality they are "on eachother" (I mean:in most pictures you see the vasa recta right from the bowman and loop of henle on the left (or the other way around), but in reality they are "on eachoter")

Anyway: 1 is the "correct" answer.
(altough, the be honest, if I had that question, I would say: none of the above....)

-pito-

pito on Tue Apr 12 15:49:57 2011 said:


Either your teacher doesnt understand it, or its a bad question.

The blood doesnt flow in those parts.. it flows next to it (in the vasa recta for example)

Another side note: the vasa recta and loop of henle: they are not like in most pictures.. In reality they are "on eachother" (I mean:in most pictures you see the vasa recta right from the bowman and loop of henle on the left (or the other way around), but in reality they are "on eachoter")

Anyway: 1 is the "correct" answer.
(altough, the be honest, if I had that question, I would say: none of the above....)



Yes, thanks - I chose #1 - it was the only one in correct order of flow of "fluid"

Interesting about the vasa recta being 'on each other"... no offense, but I hope I never have to see it in real life, :)... this one 'overview' science class is taxing my brain as it is, lol!

Thank you ever so much for your help! I really appreciate it.

-mngal-

You can google it.. if you want to see images of it (how it is in real life..)

And they are on eachother yes, thats the whole point of it. Thats why it works...

Anyway, good luck with it.

Kinda weird an art student needs to take this class.

-pito-

pito on Tue Apr 12 16:32:58 2011 said:


You can google it.. if you want to see images of it (how it is in real life..)

And they are on eachother yes, thats the whole point of it. Thats why it works...

Anyway, good luck with it.

Kinda weird an art student needs to take this class.



GenEd requirements - 1 course in the Natural Sciences plus 1 course with a LAB.....I chose what I thought would be the path of least resistance - lol - my brain's resistance to what I call 'hard science'! Will be taking Earth Science for the lab requirement course.

I can appreciate why some people would be drawn to the hard sciences - this course has been fascinating to me from the perspective of how complex our bodies are! I am awed and amazed - but I don't have the interest or ability to delve into it further; the level of detail is almost too much for my poor brain! Give me the big picture and the knowledge to be able to source details as needed, such as coming here for help, and I'm a happy camper.

Thanks again for your help and well wishes.

-mngal-