organ system

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organ system

A group of tissues or organs, often with a common embryological origin, that participate in the same major systemic activity, e.g., circulation or digestion. See: table

Particular organ systems are listed under the first word. See: e.g., digestive system; nervous system; reproductive system

SystemChief ComponentsMajor Activities
Circulatory or CardiovascularHeart, arteries, veins, blood capillaries, lymphatic vesselsMoves blood, oxygen, and nutrients to tissues. Transports hormones, leukocytes, and lymphocytes. Removes wastes and carbon dioxide from tissues.
Digestive or AlimentaryOral cavity (incl., mouth, teeth, tongue, oropharynx), esophagus, stomach, duodenum, jejunum, colon, liver, pancreasTransforms consumed materials into absorbable molecules; absorbs water and small molecules.
EndocrinePituitary (adenohypophysis and neurohypophysis), pineal gland, thyroid gland, parathyroid glands, suprarenal (adrenal) glands, pancreatic islets, neuroendocrine system, ovaries, testesRegulates metabolic processes, blood pressure, body temperature, reproductive cell cycles, and levels of blood molecules (e.g., glucose, sodium, water).
HemolymphoidErythrocytes, leukocytes, lymphocytes, platelets, hemal generating tissues, lymphoid generating tissues (e.g., thymus, lymph nodes, spleen, lymphoid nodules)Carries oxygen, facilitates clotting, attaches to threatening antigenic substances, and generates immune reactions.
IntegumentalSkin, hair, nails, subcutaneous tissuesIsolates internal tissues from the environment to help maintain body temperature, hydration, and composition; provides a barrier against infection and injury.
MuscularSkeletal, smooth, and cardiac musclesChanges the relative position of tissues in the body. Provides stability and support. Generates heat. Helps to maintain internal metabolic homeostasis (e.g., normal blood glucose levels).
NervousBrain, spinal cord, peripheral nerves, peripheral ganglia, sensory receptors (e.g., retina, cochlea), glia, Schwann cellsReceives sensory input and generates motor output. Coordinates the metabolic state and the activity types and levels throughout the body.
ReproductiveFemale: ovaries, fallopian tubes, uterus, vagina, clitoris, breasts. Male: testes, ductus deferens, spermatic cord, prostate, penisStimulates maturation and gender specificity of tissues. Allows formation and maturation of an embryo.
RespiratoryNose, paranasal sinuses, larynx, trachea, bronchi, lungsOxygenates blood and removes carbon dioxide. Generates sounds for communication.
SkeletalBones, cartilage, jointsSupports, stabilizes and protects the body. Gives the body its 3D shape.
UrinaryKidney, ureters, bladder, urethraMaintains the body's normal concentrations of salts, waters, and small molecules. Adjusts blood volume of body.