proximal convoluted tubule
Quick Summary
The proximal convoluted tubule is a crucial part of the nephron in the vertebrate kidney. Located between Bowman's capsule and the loop of Henle, this convoluted portion of the renal tubule plays a vital role in filtering blood and forming urine.12
Its primary function is the reabsorption of essential substances from the glomerular filtrate back into the bloodstream. This includes nearly all glucose and amino acids, a significant portion of water and sodium ions (about 70%), and other ions like chloride and potassium. By selectively reabsorbing these substances, the proximal convoluted tubule ensures that vital nutrients are retained by the body, while waste products are prepared for excretion. This process is critical for maintaining homeostasis and regulating the body's fluid and electrolyte balance.34
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
renal systemFormation and composition of urineAs this liquid traverses the proximal convoluted tubule, most of its water and salts are reabsorbed, some of the solutes completely and others partially; i.e., there is a separation of substances that must be retained from those due for rejection. Subsequently the loop of Henle, distal convoluted tubule, and collecting…
Read MoreAs this liquid traverses the proximal convoluted tubule, most of its water and salts are reabsorbed, some of the solutes completely and others partially; i.e., there is a separation of substances that must be retained from those due for rejection. Subsequently the loop of Henle, distal convoluted tubule, and collecting…
Read More- renal systemTubule function
…the filtrate passes along the proximal tubule, most of its water and salts are reabsorbed into the blood of the network of capillaries around the tubules. Of other substances, some are reabsorbed completely, others in part, because this portion of the nephron separates substances that must be retained in the…
Read More…the filtrate passes along the proximal tubule, most of its water and salts are reabsorbed into the blood of the network of capillaries around the tubules. Of other substances, some are reabsorbed completely, others in part, because this portion of the nephron separates substances that must be retained in the…
Read More
- excretionMammals
…capsule is continuous with the proximal convoluted tubule, which also lies in the cortex. Following the proximal convoluted tubule is the loop of Henle, which descends into the medulla and then runs straight up again to the cortex where it continues as the distal convoluted tubule. A collecting tubule, into…
Read More…capsule is continuous with the proximal convoluted tubule, which also lies in the cortex. Following the proximal convoluted tubule is the loop of Henle, which descends into the medulla and then runs straight up again to the cortex where it continues as the distal convoluted tubule. A collecting tubule, into…
Read More - renal systemMinute structure
…of each tubule, called the proximal convoluted tubule, lie in the renal cortex. The tubule descends into a renal pyramid, makes a U-shaped turn, and returns to the cortex at a point near its point of entry into the medulla. This section of the tubule, consisting of the two parallel…
Read More…of each tubule, called the proximal convoluted tubule, lie in the renal cortex. The tubule descends into a renal pyramid, makes a U-shaped turn, and returns to the cortex at a point near its point of entry into the medulla. This section of the tubule, consisting of the two parallel…
Read More
