Organ system


An organ system is a biological system consisting of a group of organs that work together to perform one or more bodily functions. Each organ has a specialized role in an organism body, and is made up of distinct tissues.

Humans

There are 11 distinct organ systems in human beings, which form the basis of human anatomy and physiology. The 11 organ systems: the respiratory system, digestive and excretory system, circulatory system, urinary system, integumentary system, skeletal system, muscular system, endocrine system, lymphatic system, nervous system, and reproductive system. 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 since it is not composed of organs. Some organs are in more than one system—for example, the nose is in the respiratory system and also serves as a sensory organ in the nervous system; the testes and ovaries are both part of the reproductive and endocrine systems.
Organ systemDescriptionComponent organs
Respiratory systembreathing: exchange of oxygen and carbon dioxidenose, mouth, paranasal sinuses, pharynx, larynx, trachea, bronchi, lungs and thoracic diaphragm
Digestive and excretory 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
Circulatory systemcirculate blood in order to transport nutrients, waste, hormones, O2, CO2, and aid in maintaining pH and temperatureblood, heart, arteries, veins and 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, 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 and testicles
Exocrine systemvarious functions including lubrication and protectionceruminous glands, lacrimal glands, sebaceous glands and mucus
Lymphatic systemreturn lymph to the bloodstream, aid immune responses, form white blood cellslymph, lymph nodes, lymph vessels, tonsils, spleen and thymus
Nervous systemsensing and processing information, controlling body activitiesbrain, spinal cord, nerves, sensory organs and the following sensory systems : visual system,smell (olfactory system), taste and hearing
Reproductive systemsex organs involved in reproductionovaries, fallopian tubes, uterus, vagina, vulva, penis, testicles, vasa deferentia, seminal vesicles and prostate

Other animals

Other animals have similar organ systems to humans, although simpler animals may have a lot of organs in an organ system or have fewer organ systems.

Plants

Plants have two major organs systems. Vascular plants have two distinct organ systems: a shoot system, and a root system. The shoot system consists stems, leaves, and the reproductive parts of the plant. The shoot system generally grows above ground, where it absorbs the light needed for photosynthesis. The root system, which supports the plants and absorbs water and minerals, is usually underground.
Organ systemDescriptionComponent organs
Root systemanchors plants into place, absorbs water and minerals, and stores carbohydratesroots
Shoot systemstem for holding and orienting leaves to the sun as well as transporting materials between roots and leaves, leaves for photosynthesis, and flowers for reproductionstem, leaves, and flowers