What process does excretion refer to?

Excretion refers specifically to the process of eliminating waste from the body. This is a crucial biological function that helps maintain homeostasis by removing harmful byproducts generated from cellular metabolism as well as excess substances that are not needed by the body. The waste products are typically excreted through various means such as urine produced by the kidneys, sweat expelled through the skin, and carbon dioxide released during respiration.

In contrast, absorption relates to the uptake of nutrients in the digestive system, which is a separate process focused on the assimilation of necessary substances rather than waste elimination. Circulation involves the movement of blood throughout the body to deliver these nutrients and oxygen, while synthesis is about the creation of proteins within cells, processes that do not pertain to the removal of waste. Thus, the definition of excretion is distinct and aligns precisely with the elimination of waste products.