GENERAL HISTOLOGY

Detailed explanation-1: -Aquaporins are channels, i.e. passive transporters where water always moves down its water potential gradient.

Detailed explanation-2: -When a person’s fluid intake is low or when a lot of fluid is lost (for example, through sweating), the body produces more ADH. This hormone triggers chemical reactions that ultimately insert aquaporin 2 water channels into the membrane of collecting duct cells.

Detailed explanation-3: -Aquaporins (AQP) are integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane. They are conserved in bacteria, plants, and animals.

Detailed explanation-4: -AQP1 is extremely abundant in the proximal tubule and descending thin limb and is essential for urinary concentration. AQP2 is exclusively expressed in the principal cells of the connecting tubule and collecting duct and is the predominant vasopressin-regulated water channel.