This body system secretes hormones through glands, which regulate the body's activity.
This body system permits movement of the body.
This body system is the control center of the body. Nerves transmit signals to and from the brain.
This body system circulates blood, which carries oxygen, around the body.
This body system eliminates waste from the body.
This body system is the body's defense against pathogens (virus, bacteria, fungi, and parasites).
