Human Body Systems and Their Major Organs

Human Body Systems

1. Respiratory System: The purpose of this system is to take in air, filter it, and take it to the tissues responsible for gas exchange. Oxygen is then transported by blood to all the tissues in the body. Carbon dioxide, a waste product, is reabsorbed and excreted from the body.
2. Skeletal System: This system forms the basic framework of the body. It supports and protects all internal organs. Bones serve as levers (with the attached muscles) for movement, produce blood cells, and store calcium salts, which can be absorbed into the blood when there is not enough calcium in the diet.
3. Endocrine System: The secretion of hormones, which regulate the body's functions chemically, is the function of this system.
4. Urinary System: This system is also called the excretory system. It filters body liquids, eliminating chemicals and excess fluids from the body.
5. Circulatory System: This system contains an important organ that pumps blood around the entire body. This is necessary to supply cells with nutrients and oxygen and to transport waste products for excretion.
6. Reproductive System: This system is essential for reproduction and the production of hormones and sex cells (gametes). It also enables conception and permits the carrying and birth of babies (offspring).
7. Digestive System: The system that changes food into simpler substances for the cells to use for energy also takes away (or eliminates) waste products from the body.
8. Integumentary System: This complex system, which is also thought of as an organ, protects the body from disease, helps to regulate body temperature, and acts as a sensory receptor.
9. Lymphatic System: A system that runs parallel with the veins throughout the body drains fluid from the tissues and helps to defend the body against disease.
10. Muscular System: We need this system to produce movement, both voluntary and involuntary, and to keep our hearts beating to keep us alive.
11. Nervous System: This is the most complex system in the body. Its functions are to regulate all the other systems in the body, receive and send messages, and provide us with information about our environment. The central nervous system includes the brain and spinal cord. The peripheral nervous system consists of nerves that connect every other part of the body to the central nervous system.

Major Organs and Their Systems

12. Major organs: skin, hair, nails, sebaceous and sweat glands: Integumentary System
13. Major organs: Female: ovaries, oviducts, vagina, mammary glands. Male: testes, seminal vesicles, and penis: Reproductive System
14. The hypothalamus, pituitary, thyroid, pancreas, and adrenal glands: Endocrine System
15. Major organs: bones, cartilage, tendons, and ligaments: Skeletal System
16. Major organs: brain, spinal cord, and peripheral nerves: Nervous System
17. Major organs: skeletal muscle and smooth muscles throughout the body: Muscular System
18. Major organs: lymph, lymph nodes and vessels, white blood cells, T- and B- cells: Lymphatic System
19. Major organs: kidney, ureters, bladder, and urethra: Excretory System
20. Major organs: nose, trachea, lungs, bronchi, bronchioles, alveoli, larynx, and pharynx: Respiratory System
21. Major organs: mouth, esophagus, stomach, small intestine (duodenum, jejunum, and ileum) and large intestine (cecum, colon, and rectum), salivary glands, liver, gallbladder, and anus: Digestive System
22. Major organs: heart (right and left atriums and right and left ventricles), blood vessels (arteries, veins, and capillaries), and blood: Circulatory System