What term describes the normal process of excreting urine?

The term that describes the normal process of excreting urine is urination. This term specifically refers to the act of discharging urine from the urinary bladder through the urethra to the outside of the body. It is an important physiological function that helps to maintain the body's fluid balance and eliminate waste products.

In the context of other potential choices, excretion is a broader term that refers to the process of removing waste materials from the body, which includes not just urine but also other waste elimination processes. Filtration is primarily associated with the kidneys filtering blood to form urine, but it does not describe the actual expulsion of urine itself. Defecation pertains specifically to the elimination of solid waste from the digestive tract and is unrelated to the urinary system. Thus, urination is the most accurate term for the specific act of excreting urine.