Materials are Returned to the Blood from the Filtrate by Which

Question

Materials are returned to the blood from the filtrate by which of the following processes?
A) filtration
B) ultrafiltration
C) selective reabsorption
D) secretion
E) active transport

Accepted Answer

Selective reabsorption is the process by which materials (such as glucose, amino acids, ions, and water) that are needed by the body are transported back into the bloodstream from the filtrate in the kidney tubules. Filtration and ultrafiltration occur initially in the nephron, which allows small molecules to pass through the glomerular membrane into the renal tubules. Secretion is the process by which waste products and excess ions are moved from the blood into the renal tubules for excretion. Active transport is a type of selective reabsorption that requires energy to move molecules against a concentration gradient.