The Body

• Circulatory- This system includes the heart and veins. It delivers oxygen that the respiratory system provides, in addition to other substances.
• Digestive- This system includes the stomach, small intestine, large intestine, mouth, and liver. It provides nutrition to the body, so all the other systems benefit.
• Nervous- The nervous system includes the brain, brainstem, spinal cord, and nerves. It interacts with the circulatory and digestive system by involuntarily keeping them active.
• Endocrine- The endocrine system is a way of providing hormones that regulate various systems. It releases, for example, adrenaline, which helps the circulatory system work harder as part of the fight or flight response.
• Reproductive- This system consists of the testes and penis or the ovaries and vagina. It interacts with the circulatory system in males because blood is used to cause erections.
• Respiratory- The respiratory system consists of the lungs, and it interacts with the circulatory system by providing the oxygen that the blood delivers.
• Excretory (including the urinary)- This system contains the kidneys, large intestine, liver, skin, ureters, bladder, and urethra. It interacts with the digestive system, getting rid of waste products that result from digestion.
• Immune system- The immune system consists primarily of the thymus and bone marrow. It protects the body from diseases. It interacts with the cardiovascular system