Which components of glomerular filtrate reenter the blood?

The components of glomerular filtrate that reenter the blood primarily include water, glucose, and ions. This process occurs during reabsorption in the nephron, specifically in the proximal convoluted tubule and loop of Henle.

Water is reabsorbed from the filtrate to maintain fluid and electrolyte balance in the body. Glucose, which is a vital energy source for the body's cells, is almost entirely reabsorbed in the proximal convoluted tubule through specific transport proteins. Ions, such as sodium, potassium, and bicarbonate, are also reabsorbed to regulate various physiological functions, including nerve transmission and muscle contraction, as well as to help maintain acid-base balance.

While urea and creatinine do appear in glomerular filtrate, they are typically not reabsorbed back into the bloodstream and instead are excreted in urine. Proteins and fats are generally not present in significant amounts in the filtrate due to their size and are usually not means of reabsorption. Hormones and enzymes are not part of the glomerular filtrate and play different roles in the body, often related to signaling or catalyzing reactions rather than being reabsorbed from the renal system.