Aldosterone and ADH???

[Diocletian]

Where do aldosterone and ADH mainly act? I always thought that both were in
the Distal Convoluted Tubule but my book is saying Collecting Duct.

Do they act on both parts equally?

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[MedPR]

Where do aldosterone and ADH mainly act? I always thought that both were in
the Distal Convoluted Tubule but my book is saying Collecting Duct.

Do they act on both parts equally?

Aldosterone = DCT
ADH = Collecting duct

 

[deleted357625]

ADH acts on the distal and collecting tubules
Aldosterone..not sure lol

 

[IRASNA]

Both work on collecting duct & DCT. Aldosterone increases Na/K pumps. ADH allows for water reabsorption (aquaporin ii channels). As you reabsorb Na...water wants to follow. It will only be able to follow when aquaporn II is there via ADH.

 

[MedPR]

For the MCAT Aldosterone mainly acts in the DCT and ADH mainly acts in the collecting duct.

 

[Morsetlis]

The important thing is their actions: Aldosterone upregulate ROMK, Na/K ATPase, and activate ENaC, reabsorbing Sodium, and thus water follows.

ADH activates the NKCC triple transporter in the thick ascending limb AND upregulate aquaporin 2 via V2 receptors in the collecting ducts. This opens up channels that allows water to be reabsorbed WITHOUT Sodium following.

Increasing osmolarity, via thirst receptors in the hypothalamus (perhaps the subfornical organ or OVLT?) will trigger ADH release to reabsorb water.

Hypovolemia or high K+ via the RAAS will trigger aldosterone release to reabsorb Sodium, and thus water follows.

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I'm not sure any of this will be useful in the MCAT. Try instead to understand why water follows Sodium.

 

[wanderer]

If you look at where physiological control of the amount of water and salt that is reabsorbed you'll see it's most important in the collecting system. So for now it's most important to remember that ADH and aldosterone both control the (principal cells of the) collecting system.