What are the differences between the filtrate and plasma?
The difference between urine and plasma lies in the fact that urine contains a low level of protein, almost no protein components, while plasma contains a relatively high level of protein, and their compositions are basically similar. Of course, besides this difference, their sources are also different. Urine is formed when substances such as uric acid and glucose in the blood are filtered by the glomerulus. Plasma, on the other hand, exists in the blood and maintains the osmotic pressure of the body's fluids and crystals.
Urine is produced when blood passes through the renal tubules, and substances such as blood urea, urea solution, water carbonates, and glucose are filtered by the renal tubules into the renal pelvis. When urine flows through the renal tubules and causes damage, all the glucose, most of the water, and some of the carbonates that are beneficial to the body in the urine are reabsorbed by the damaged renal tubules.
Plasma contains a high concentration of hemoglobin and a rich amount of glucose, which is referred to as blood sugar. When the renal tubules of the kidneys filter the blood sugar, urine is produced, and its composition is basically the same as blood. If the blood sugar concentration is too high, the glucose concentration in the urine will also increase. Blood, especially, is the main substance for the body's metabolism, playing a role in transporting nutrients to tissue cells and excreting metabolic waste. Plasma contains more nutrients, while urine is a liquid filtered by the glomerulus, and its main components are water, salt, and some metabolites.