ADH and Aldosterone

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I am a little confused, because first- kaplan says that ADH increasese the urine concentration, then it says that ADH makes the distal tubule and collecting duct more permeable to water...

I guess its a mistake when they say that the urine will become more concentrated?

 

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btw, i noticed this in the flashcards.

 

[Hernandez]

I am a little confused, because first- kaplan says that ADH increasese the urine concentration, then it says that ADH makes the distal tubule and collecting duct more permeable to water...

I guess its a mistake when they say that the urine will become more concentrated?

No, Kaplan is correct, ADH (or as most texts refer to it AVP) is a hormone released in responce to hypertonicity, wihch in turn causes an increase in the number of water channels in the distal tuble/cc, which in turn causes an net reabsorption of free water, "The net effect is passive water reabsorption along an osmotic gradient from the lumen of the collecting duct to the hypertonic medullary interstitium"

 

[Kikaku21]

btw, i noticed this in the flashcards.

The urine becomes more concentrated, i.e. has higher osmolarity because you remove water from it by making the distal tubule more permeable. Make Sense?

 

[xx216xx]

right, i think you're just a little confused with the terms. ADH increases water reabsorption thus increasing urine concentration, that is number of solutes per volume of water.

EDIT: lol, we were all within a minute of each other

 

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OK so, am I interpreting this right?

aldosterone- increases H2O and Na re-absoption back in to the blood right? Which means it decreases the water concentration inside the distal tubule , right?


and ADH makes the collecting duct more permeable to water, thus sending the water out because our goal here again is to make the urine concentrated right?

So ultimately, both ADH and aldosterone help us in our goal of achieving concentrated urine right?

 

[EBI831]

yes i suppose you are correct but i would just like to say that aldosterone isn't really that concerned with increasing the concentration of urine unless it wouldn't remove sodium, an ion that would increase concentration, as well. it's main function is to facilitate reabsorption of salts back into the body and raise the blood pressure and increase plasma osmolarity so i don't know if it really increases concentration of urine because it does remove some solute too. but for mcat purposes i guess maybe you are correct...most def on the ADH one tho.

 

[Noeljan]

both increase reabsorption of water at the collecting duct, and both increase volume. Increasing either one would seem to lead to a more concentrated urine, though I'm not sure how in depth the MCAT would get after that. I like to think of it this way, you know how when you drink alcohol you pee a LOT (well at least I do). I do so much its ridiculous. Also, I notice how I have dreams about drinking tons of juice when I drink. I usually am dehydrated. The urine is usually very clear (dilute(. Basically, alcohol inhibits secretion of ADH. Thus leading to increased dilute urine output, and dehydration (less urine absorbed). When I make this analogy to myself, it is easy to remember the action of ADH, and the subsequent effects🙂 🙂
ps I don't drink that much, but when I do it's not pretty.

 

[UMP]

ADH is Anti-Diuretic Hormone... remembering the name should be enough to know what it does, considering diarrhea makes you lose water...

knowing the inside and out of how ADH effects the kidney reabsorption is very high yield in my opinion, it seems to come up on every practice Bio section I take