Which of the following is least likely to be present in the glomerular...
In a healthy adult nephron, large molecular weight proteins are least likely to be present in the glomerular filtrate. The glomerular filtration process selectively allows the passage of small molecules and ions, while larger molecules such as proteins are usually excluded.
The glomerular filtration barrier consists of three layers: the fenestrated endothelium of the glomerular capillaries, the basement membrane, and the filtration slits formed by podocytes. This barrier acts as a sieve, allowing small molecules like water, ions, glucose, and amino acids to pass through, while preventing the passage of larger molecules, including most proteins.
Amino acids, glucose, and electrolytes are small molecules that are present in the glomerular filtrate. Amino acids are essential building blocks for protein synthesis, glucose is a vital energy source, and electrolytes are involved in various physiological processes.
Large molecular weight proteins, on the other hand, are normally retained within the bloodstream due to their size and charge. They are generally not filtered through the glomerular filtration barrier. Any presence of large proteins in the filtrate would indicate a malfunction or damage to the filtration barrier, which can occur in certain kidney diseases or conditions.
Therefore, option D, large molecular weight protein, is least likely to be present in the glomerular filtrate of a healthy adult nephron.