Final answer:
The glomerular filtrate is known as serum, which is plasma without the proteins. It's formed during glomerular filtration when blood pressure pushes solutes out of the blood, creating a filtrate that eventually becomes urine. The GFR is a key measure of this process and kidney function.
Step-by-step explanation:
The glomerular filtrate is essentially plasma without proteins, and this fluid is commonly referred to as serum.
The process of glomerular filtration occurs when blood pressure forces water and solutes out of the blood and into Bowman's capsule, creating a filtrate. This filtrate then enters the renal tubule, marking the first step in the formation of urine. Critical to note is that while serum matches the composition of plasma, it lacks clotting factors and macromolecules like proteins. Glomerular filtration rate (GFR), an important indicator of kidney function, represents the volume of serum produced by the kidneys per minute.
During this process, only small molecules such as ions, amino acids, vitamins, and wastes can pass through the specialized membranes and 'leaky' connections of the glomerular capillaries. The GFR and filtration fraction play crucial roles in maintaining the body’s fluid and electrolyte balance, reflecting the kidneys' efficiency in filtering blood plasma and forming urine.