The human body consists of 78 organs. Of these 78 organs, five are vital organs. They are the brain, heart, lungs, liver and kidneys.
Many organs form part of organ systems. They work together to perform specific functions. The organ systems of the body include the nervous system, reproductive system, integumentary system, muscular system, endocrine system, immune system, digestive system and circulatory system.
The brain and the spinal cord form the core of the central nervous system. The nervous system helps the body to regulate every function.
The reproductive system is the only system which is different in men and women. In women, the reproductive system supports the growth of the fetus.
The integumentary system includes the skin, the largest organ in the human body. It helps to regulate body temperature and make vitamin D from sunlight.
The muscular system includes a vast network of muscles. They can be divided into voluntary and involuntary muscles. Voluntary muscles are muscles that individuals can move when they wish.
The endocrine system is a network of glands throughout the body. They release hormones which help to regular the function of organs in the body.
The immune system helps the body to prevent infections and to fight them when they occur. Many organs play a role in the immune system. The skin helps to prevent dangerous microorganisms from entering the body.
The digestive system is the group of organs which digest food. These organs also release substances to aid digestion and absorption. The mouth, liver and stomach form part of the digestive system.
The circulatory system includes blood vessels. Their role is to circulate blood throughout the body.
The human body is composed of many organs. They work together in organ systems which perform various functions. The study of the structures of the human body is known as human anatomy.