organ system
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. |
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