Nervous system. It uses nerves to transmit messages through the body and responds to action in the outside environment. Its major organs are the brain, peripheral nerves and spinal cord. It works closely with skeletal system and muscular system.
Cardiovascular system. It regulates body temperature, fights infections, removes cell waste and it brings oxygen to cells. Its major organs are arteries, veins, heart, and blood vessels. It interacts with the digestive system to help red blood cells to carry nutrients and digested food in the body. It reacts with endocrine which helps red blood cells to carry hormones which deliver a message to the body.
Respiratory system. Its work in the body helps in breathing.Its major organs are lungs, pharynx and nose.works closely with immune, excretory system and circulatory system.
Muscular system. Helps in the circulation of foods and blood and allows it to produce voluntary movement.Its major organs are cardiac muscles, smooth and skeletal muscles.
Digestive system. It absorbs and converts food into molecules for cell use and it also helps in elimination of solid waste. Its organs are mouth, stomach, and intestines. It interacts with cardiovascular and excretory systems.
Urinary system. It helps in elimination of salt, excess water, and body waste. Its organs are bladder, urethra, urinary tract, and ureterus. It reacts with the nervous system where bladder sends sensory into the brain and then brain control urination.
Endocrine system. It maintains homeostasis and controls growth and development through hormones. Its main organs are testes, ovaries, and glands. It works closely with reproductive, digestive, nervous, and cardiovascular.