The body systems interrelate with each other to ensure an organism functions normally. The brain receives information from other body systems to ensure proper functioning of the body. Examples of body systems include the circulatory system, digestive system, endocrine system, integumentary system, muscular system, nervous system, reproductive system, respiratory system, skeletal system and urinary/excretory system. Each system depends on others, either directly or indirectly.
The circulatory system transports nutrients and gases to cells and tissues throughout the body. This is facilitated by blood circulation. The digestive system breaks down food into smaller particles that can be absorbed into the body. The endocrine system regulates vital processes including growth, homeostasis, metabolism and sexual development. Endocrine organs secrete hormones that regulate the body processes. The integumentary system, which is comprised of the skin, nails, hair and sweat glands, protects the internal structure of the body from damage, stores fat, prevents dehydration and produces vitamins and hormones. The muscular system enables movement through the contraction of muscles. The respiratory system ensures supply of oxygen to the body. The bones, joints, ligaments, tendons and cartilage make up the skeletal system, which supports and protects the body, giving it shape and form. The urinary/excretory system, which consists of the urinary bladder, urethra and ureters, removes wastes and maintains water balance in the body.