This presentation discusses the process of excretion in the human body. It contains the following key points: 1. Kidneys act as filters to remove waste from the bloodstream in the form of urine. The average human has two kidneys located near the backbone. 2. Urine is transported from the kidneys to the bladder via the ureters. The bladder stores urine until it is released from the body through the urethra. 3. The kidneys, ureters, bladder, and urethra work together to remove toxins and regulate fluid levels in the body through urination.