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.
Fifth Grade: Patterns; Scale, Proportion, and Quantity
Physical Sciences: Students develop an understanding that changes can occur to matter/objects on Earth or in space, but both energy and matter follow the pattern of being conserved during those changes.
Physical Science Standards
Analyze and interpret data to explain that matter of any type can be subdivided into particles too small to see and, in a closed system, if properties change or chemical reactions occur, the amount of matter stays the same.