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

System	Chief Components	Major Activities
Circulatory or Cardiovascular	Heart, arteries, veins, blood capillaries, lymphatic vessels	Moves blood, oxygen, and nutrients to tissues. Transports hormones, leukocytes, and lymphocytes. Removes wastes and carbon dioxide from tissues.
Digestive or Alimentary	Oral cavity (incl., mouth, teeth, tongue, oropharynx), esophagus, stomach, duodenum, jejunum, colon, liver, pancreas	Transforms consumed materials into absorbable molecules; absorbs water and small molecules.
Endocrine	Pituitary (adenohypophysis and neurohypophysis), pineal gland, thyroid gland, parathyroid glands, suprarenal (adrenal) glands, pancreatic islets, neuroendocrine system, ovaries, testes	Regulates metabolic processes, blood pressure, body temperature, reproductive cell cycles, and levels of blood molecules (e.g., glucose, sodium, water).
Hemolymphoid	Erythrocytes, 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.
Integumental	Skin, hair, nails, subcutaneous tissues	Isolates internal tissues from the environment to help maintain body temperature, hydration, and composition; provides a barrier against infection and injury.
Muscular	Skeletal, smooth, and cardiac muscles	Changes 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).
Nervous	Brain, spinal cord, peripheral nerves, peripheral ganglia, sensory receptors (e.g., retina, cochlea), glia, Schwann cells	Receives sensory input and generates motor output. Coordinates the metabolic state and the activity types and levels throughout the body.
Reproductive	Female: ovaries, fallopian tubes, uterus, vagina, clitoris, breasts. Male: testes, ductus deferens, spermatic cord, prostate, penis	Stimulates maturation and gender specificity of tissues. Allows formation and maturation of an embryo.
Respiratory	Nose, paranasal sinuses, larynx, trachea, bronchi, lungs	Oxygenates blood and removes carbon dioxide. Generates sounds for communication.
Skeletal	Bones, cartilage, joints	Supports, stabilizes and protects the body. Gives the body its 3D shape.
Urinary	Kidney, ureters, bladder, urethra	Maintains the body's normal concentrations of salts, waters, and small molecules. Adjusts blood volume of body.