Organ system


An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ does a particular job in the body, and is made up of distinct tissues.

Organs systems and their functions

There are eleven distinct organ systems in human beings, which form the basis of anatomy. Other animals have similar organ systems, although simpler animals may have fewer organs in an organ system or even fewer organ systems. Plants too have organs, such as flowers and leaves, and these are grouped into organ systems as well.
Organ SystemDescriptionComponent Organs
Respiratory systembreathing: exchange of oxygen and carbon dioxidenose, mouth, sinus, pharynx, larynx, trachea, bronchi, lungs and diaphragm.
Digestive systemdigestion: breakdown and absorption of nutrients, excretion of solid wastesteeth, tongue, salivary glands, esophagus, stomach, liver, gallbladder, pancreas, small intestine, large intestine, rectum and anus
Cardiovascular systemcirculate blood in order to transport nutrients, waste, hormones, O2, CO2, and aid in maintaining pH and temperatureblood, heart, arteries, veins, capillaries
Urinary systemmaintain fluid and electrolyte balance, purify blood and excrete liquid waste kidneys, ureters, bladder and urethra
Integumentary systemexterior protection of body and thermal regulationskin, hair, exocrine glands, fat, and nails
Skeletal systemstructural support and protection, production of blood cellsbones, cartilage, ligaments and tendons.
Muscular systemmovement of body, production of heatskeletal muscles, smooth muscles and cardiac muscle
Endocrine systemcommunication within the body using hormones made by endocrine glandshypothalamus, pituitary, pineal gland, thyroid, parathyroid and adrenal glands, ovaries, testes
Lymphatic systemreturn fluids to blood stream, aid immune responses, form white blood cellslymph, lymph nodes, lymph vessels, tonsils, spleen, thymus
Nervous systemsensing and processing information, controlling body activitiesbrain, spinal cord, nerves, sensory organs
Reproductive systemsex organs involved in reproductionovaries, fallopian tubes, uterus, vagina, mammary glands, penis, testes, vas deferens, seminal vesicles and prostate

There are other systems in the body that are not organ systems. For example, the Immune system protects the organism from infection, but it is not an organ system as it is not composed of organs.
Some organs are in more than one system. For example, the nose is in both the respiratory system and also is a sensory organ in the nervous system. The testes and ovary are both part of the reproductive systems and endocrine systems.