The excretory system is responsible for removing waste and excess substances from the body. It consists of several organs, including the kidneys, ureters, bladder, and urethra.
The kidneys are the main organs of the excretory system. They filter waste products and excess substances, such as urea, from the blood to form urine. The urine then travels from the kidneys to the bladder through the ureters.
The bladder is a hollow, muscular organ that stores urine until it is expelled from the body. When the bladder is full, it sends signals to the brain, prompting the urge to urinate.
Use models to describe that energy in animals’ food (used for body repair, growth, motion, and to maintain body warmth) was once energy from the sun.