5:28 94 d2l.laurentian.ca Quiz 3 0:40:26 elapsed Most water is reabsorbed in the proximal convoluted tubules by obligatory reabsorption, which means that a) water is moving up its gradient b) noradrenalin c) the carrier that transports \( \mathrm{Na}^{+} \)cannot do so without binding water first d) water is "following" \( \mathrm{Na}^{+} \)and other \( \leftarrow \) innc/mnlarilactn 14

In the fascinating world of kidney function, the proximal convoluted tubule (PCT) plays a key role in reabsorbing about 65% of the filtered water, along with essential solutes like sodium. This process is known as obligatory reabsorption because it doesn’t require energy per se; instead, water naturally follows solutes, such as sodium ions, moving down their concentration gradients through osmosis. It's almost like a well-coordinated dance where sodium leads and water gracefully follows! In practical terms, understanding how water reabsorption occurs in the PCT can be vital for medical professionals as it directly impacts conditions like dehydration or kidney disease. For instance, certain medications can affect this reabsorption process, leading to either excess water retention or rapid water loss. This knowledge helps in tailoring treatments for optimal patient outcomes, ensuring that our body's fluid balance is maintained effectively.