List of systems of the human body
This is a list of the main systems of the human body, including organ systems. An organ system is a group of organs that work together to perform major functions or meet physiological needs of the body.
Major organ systems
There are 11 to 12 distinct organ systems. The endocrine and exocrine systems are sometimes referred to jointly as the endocrine system.| Organ system | Description | Component organs |
| Respiratory system | breathing; exchange of oxygen and carbon dioxide | nose, mouth, paranasal sinuses, pharynx, larynx, trachea, bronchi, lungs and thoracic diaphragm |
| Digestive and excretory system | digestion; breakdown and absorption of nutrients, excretion of solid wastes | teeth, tongue, salivary glands, esophagus, stomach, liver, gallbladder, pancreas, small intestine, large intestine, rectum and anus |
| Circulatory system | circulate blood in order to transport nutrients, waste, hormones, O2, CO2, and aid in maintaining pH and temperature | blood, heart, arteries, veins and capillaries |
| Urinary system | maintain fluid and electrolyte balance, purify blood and excrete liquid waste | kidneys, ureters, bladder and urethra |
| Integumentary system | exterior protection of body and thermal regulation | skin, hair, fat and nails |
| Skeletal system | structural support and protection, production of blood cells | bones, cartilage, ligaments and tendons |
| Muscular system | movement of body, production of heat | skeletal muscles, smooth muscles and cardiac muscle |
| Endocrine system | communication within the body using hormones made by endocrine glands | hypothalamus, pituitary, pineal gland, thyroid, parathyroid and adrenal glands, ovaries and testicles |
| Exocrine system | various functions including lubrication and protection | ceruminous glands, lacrimal glands, sebaceous glands and mucus |
| Lymphatic system | return lymph to the bloodstream, aid immune responses, form white blood cells | lymph, lymph nodes, lymph vessels, tonsils, spleen and thymus |
| Nervous system | sensing and processing information, controlling body activities | brain, spinal cord, nerves, sensory organs |
| Reproductive system | sex organs involved in reproduction | ovaries, fallopian tubes, uterus, vagina, vulva, penis, testicles, vasa deferentia, seminal vesicles and prostate |
Organ sub-systems
Cardiovascular
- Cardiac conduction system
Lymphatic
- Glymphatic system
Nervous
- Central nervous system
- Peripheral nervous system
- * Autonomic nervous system
- ** Sympathetic nervous system
- ** Parasympathetic nervous system
- ** Enteric nervous system
- * Somatic nervous system
- ** Sensory nervous system
- *** Somatosensory system
- *** Visual system
- *** Olfactory system
- *** Gustatory system
- *** Auditory system
- **** Vestibular system
Reproductive
- Female reproductive system
- Male reproductive system
Other systems
- Genitourinary system
- Haematopoietic system
- Immune system
- * Innate immune system
- * Adaptive immune system
- * Mononuclear phagocyte system
- * Reticuloendothelial system
- Musculoskeletal system
- Neuroendocrine system