As blood passes through the capillary at the start of the nephron, small molecules are filtered out and pass into the nephron tubule. These small molecules include glucose, urea, ions and water. However, large molecules, such as blood proteins, are too big to fit through the capillary wall and remain in the blood.
Reabsorption: The filtered liquid continues through a series of twisted tubes called the convoluted tubules which are surrounded by capillaries. The tubules of the nephron that lead away from the Bowman’s capsule are known as the proximal convoluted tubules and they straighten out to form a long loop called the Loop of Henle. There are then another series of twists called the distal convoluted tubules which lead to a straighten collecting duct which leads to the pelvis of the kidney and on to the ureter.
The composition of the filtered liquid alters as it flows through the convoluted tubules. Some substances contained within the waste, such as glucose, amino acids, mineral salts and vitamins are reabsorbed back into the bloodstream as the body cannot afford to lose them.…show more content… The reabsorption of salts and water is variable and is associated with maintenance of a stable condition of acidity/alkalinity and electrolyte (sodium and potassium) balance of body fluids. Excess water, salts and the waste product urea are all filtered and processed through the kidney and the treated blood leaves the kidney via the renal vein. Some substances are not removed from the blood completely in the glomerular filtrate such as the residue of medicinal drugs. These substances are passed from the blood, in particular, into the distal convoluted tubule by secretion in order that they may be excreted in the