The urinary system and the nervous system are primarily involved in sending urine out of the body.1. Urinary System – This system filters waste from the blood and removes it as urine. It includes:Kidneys – Filter waste and produce urine.Ureters – Transport urine from the kidneys to the bladder.Bladder – Stores urine until it is ready to be expelled.Urethra – The tube that carries urine out of the body.2. Nervous System – Controls when and how urine is expelled.The brain and spinal cord send signals to the bladder to contract and release urine when needed.