Urine (from Latin urina, -ae, f.) is a liquid by-product of the body secreted by the kidneys through a process called urination (or micturition) and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require clearance from the bloodstream. These by-products are eventually expelled from the body during urination, the primary method for excreting water-soluble chemicals from the body. These chemicals can be detected and analyzed by urinalysis. Human urine, together with human feces, are collectively referred to as human waste or human excreta.