**Organ Systems** Organ systems are composed of two or more different organs that work together to provide a common function. There are 10 major organ systems in the human body, they are the: - Skeletal System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/skeletal.jpg](<httpwebjjaycunyedu~acarpiNSCimagesskeletaljpg.jpg>)<br><br>Image courtesy of A. McGann|**Major Role:** <br>The main role of the skeletal system is to provide support for the body, to protect delicate internal organs and to provide attachment sites for the organs.| |**Major Organs:** <br>Bones, cartilage, tendons and ligaments.| - Muscular System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/muscular.jpg](<httpwebjjaycunyedu~acarpiNSCimagesmuscularjpg.jpg>) <br>Image courtesy of G. Huang|**Major Role:** <br>The main role of the muscular system is to provide movement. Muscles work in pairs to move limbs and provide the organism with mobility. Muscles also control the movement of materials through some organs, such as the stomach and intestine, and the heart and circulatory system.| |**Major Organs:** <br>Skeletal muscles and smooth muscles throughout the body.| - Circulatory System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/circulatory.jpg](<httpwebjjaycunyedu~acarpiNSCimagescirculatoryjpg.jpg>) <br>Image courtesy of G. Huang|**Major Role:** <br>The main role of the circulatory system is to transport nutrients, gases (such as oxygen and CO2), hormones and wastes through the body.| |**Major Organs:** <br>Heart, blood vessels and blood.| - Nervous System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/nervous.jpg](<httpwebjjaycunyedu~acarpiNSCimagesnervousjpg.jpg>) <br>Image courtesy of G. Huang|**Major Role:** <br>The main role of the nervous system is to relay electrical signals through the body. The nervous system directs behaviour and movement and, along with the endocrine system, controls physiological processes such as digestion, circulation, etc.| |**Major Organs:** <br>Brain, spinal cord and peripheral nerves.| - Respiratory System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/respiratory.jpg](<httpwebjjaycunyedu~acarpiNSCimagesrespiratoryjpg.jpg>)<br><br>Image courtesy of A. McGann|**Major Role:** <br>The main role of the respiratory system is to provide gas exchange between the blood and the environment. Primarily, oxygen is absorbed from the atmosphere into the body and carbon dioxide is expelled from the body.| |**Major Organs:** <br>Nose, trachea and lungs.| - Digestive System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/digestive.jpg](<httpwebjjaycunyedu~acarpiNSCimagesdigestivejpg.jpg>)<br><br>Image courtesy of A. McGann|**Major Role:** <br>The main role of the digestive system is to breakdown and absorb nutrients that are necessary for growth and maintenance.| |**Major Organs:** <br>Mouth, esophagus, stomach, small and large intestines.| - Excretory System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/excretory.jpg](<httpwebjjaycunyedu~acarpiNSCimagesexcretoryjpg.jpg>) <br>Image courtesy of G. Huang|**Major Role:** <br>The main role of the excretory system is to filter out cellular wastes, toxins and excess water or nutrients from the circulatory system.| |**Major Organs:** <br>Kidneys, ureters, bladder and urethra.| - Endocrine System: | | | |---|---| |![http://web.jjay.cuny.edu/~acarpi/NSC/images/endocrine.jpg](<httpwebjjaycunyedu~acarpiNSCimagesendocrinejpg.jpg>) <br>Image courtesy of G. Huang|**Major Role:** <br>The main role of the endocrine system is to relay chemical messages through the body. In conjunction with the nervous system, these chemical messages help control physiological processes such as nutrient absorption, growth, etc.| |**Major Organs:** <br>Many glands exist in the body that secrete endocrine hormones. Among these are the hypothalamus, pituitary, thyroid, pancreas and adrenal glands.| - Reproductive System: | | | |---|---| |Female: ![http://web.jjay.cuny.edu/~acarpi/NSC/images/reproductivefemale.jpg](<httpwebjjaycunyedu~acarpiNSCimagesreproductivefemalejpg.jpg>)<br><br> <br>Male: ![http://web.jjay.cuny.edu/~acarpi/NSC/images/reproductivemale.jpg](<httpwebjjaycunyedu~acarpiNSCimagesreproductivemalejpg.jpg>) <br>Images courtesy of G. Huang|**Major Role:** <br>The main role of the reproductive system is to manufacture cells that allow reproduction. In the male, sperm are created to inseminate egg cells produced in the female.| |**Major Organs:** <br>Female (top): ovaries, oviducts, uterus, vagina and mammary glands. <br>Male (bottom): testes, seminal vesicles and penis.| - Lymphatic/Immune System: | | | |---|---| |Image not available|**Major Role:** <br>The main role of the immune system is to destroy and remove invading microbes and viruses from the body. The lymphatic system also removes fat and excess fluids from the blood.| |**Major Organs:** <br>Lymph, lymph nodes and vessels, white blood cells, T- and B- cells.| **Major organ systems** _Main article:_ [_Biological system_](http://en.wikipedia.org/wiki/Biological_system) - [Circulatory system](http://en.wikipedia.org/wiki/Circulatory_system): pumping and channeling [blood](http://en.wikipedia.org/wiki/Blood) to and from the body and lungs with [heart](http://en.wikipedia.org/wiki/Heart), [blood](http://en.wikipedia.org/wiki/Blood), and [blood vessels](http://en.wikipedia.org/wiki/Blood_vessel). - [Digestive System](http://en.wikipedia.org/wiki/Gastrointestinal_tract): digestion and processing food with [salivary glands](http://en.wikipedia.org/wiki/Salivary_gland), [esophagus](http://en.wikipedia.org/wiki/Esophagus), [stomach](http://en.wikipedia.org/wiki/Stomach), [liver](http://en.wikipedia.org/wiki/Liver), [gallbladder](http://en.wikipedia.org/wiki/Gallbladder), [pancreas](http://en.wikipedia.org/wiki/Pancreas), [intestines](http://en.wikipedia.org/wiki/Intestine), [rectum](http://en.wikipedia.org/wiki/Rectum), and [anus](http://en.wikipedia.org/wiki/Anus). - [Endocannabinoid system](http://en.wikipedia.org/wiki/Endocannabinoid_system): neuromodulatory [lipids](http://en.wikipedia.org/wiki/Lipids) and receptors involved in a variety of physiological processes including [appetite](http://en.wikipedia.org/wiki/Appetite), pain-sensation, [mood](http://en.wikipedia.org/wiki/Mood), [motor learning](http://en.wikipedia.org/wiki/Motor_learning), [synaptic plasticity](http://en.wikipedia.org/wiki/Synaptic_plasticity), and [memory](http://en.wikipedia.org/wiki/Memory). - [Endocrine system](http://en.wikipedia.org/wiki/Endocrine_system): communication within the body using [hormones](http://en.wikipedia.org/wiki/Hormone) made by [endocrine glands](http://en.wikipedia.org/wiki/Endocrine_gland) such as the [hypothalamus](http://en.wikipedia.org/wiki/Hypothalamus), [pituitary](http://en.wikipedia.org/wiki/Pituitary) or pituitary gland, [pineal body](http://en.wikipedia.org/wiki/Pineal_body) or pineal gland, [thyroid](http://en.wikipedia.org/wiki/Thyroid), [parathyroids](http://en.wikipedia.org/wiki/Parathyroid), and [adrenals](http://en.wikipedia.org/wiki/Adrenal) or adrenal glands - [Integumentary system](http://en.wikipedia.org/wiki/Integumentary_system): [skin](http://en.wikipedia.org/wiki/Human_skin), [hair](http://en.wikipedia.org/wiki/Hair) and [nails](http://en.wikipedia.org/wiki/Nail_(anatomy)) - [Immune system](http://en.wikipedia.org/wiki/Immune_system): the system that fights off disease; composed of [leukocytes](http://en.wikipedia.org/wiki/Leukocytes), [tonsils](http://en.wikipedia.org/wiki/Tonsils), [adenoids](http://en.wikipedia.org/wiki/Adenoids), [thymus](http://en.wikipedia.org/wiki/Thymus), and [spleen](http://en.wikipedia.org/wiki/Spleen). - [Lymphatic system](http://en.wikipedia.org/wiki/Lymphatic_system): structures involved in the transfer of lymph between tissues and the blood stream, the [lymph](http://en.wikipedia.org/wiki/Lymph) and the [nodes](http://en.wikipedia.org/wiki/Lymph_node) and [vessels](http://en.wikipedia.org/wiki/Lymph_vessel) that transport it. - [Musculoskeletal system](http://en.wikipedia.org/wiki/Musculoskeletal_system): [muscles](http://en.wikipedia.org/wiki/Muscle) provide movement and a [skeleton](http://en.wikipedia.org/wiki/Skeleton) provides structural support and protection with [bones](http://en.wikipedia.org/wiki/Bone), [cartilage](http://en.wikipedia.org/wiki/Cartilage), [ligaments](http://en.wikipedia.org/wiki/Ligament), and [tendons](http://en.wikipedia.org/wiki/Tendon). - [Nervous system](http://en.wikipedia.org/wiki/Nervous_system): collecting, transferring and processing information with [brain](http://en.wikipedia.org/wiki/Human_brain), [spinal cord](http://en.wikipedia.org/wiki/Spinal_cord), [peripheral nerves](http://en.wikipedia.org/wiki/Peripheral_nerve), and [nerves](http://en.wikipedia.org/wiki/Nerve) - [Reproductive system](http://en.wikipedia.org/wiki/Reproductive_system): the sex organs; in the female; [ovaries](http://en.wikipedia.org/wiki/Ovary), [fallopian tubes](http://en.wikipedia.org/wiki/Fallopian_tube), [uterus](http://en.wikipedia.org/wiki/Uterus), [vagina](http://en.wikipedia.org/wiki/Vagina), [mammary glands](http://en.wikipedia.org/wiki/Mammary_gland), and in the male; [testes](http://en.wikipedia.org/wiki/Testes), [vas deferens](http://en.wikipedia.org/wiki/Vas_deferens), [seminal vesicles](http://en.wikipedia.org/wiki/Seminal_vesicle), [prostate](http://en.wikipedia.org/wiki/Prostate), and [penis](http://en.wikipedia.org/wiki/Penis). - [Respiratory system](http://en.wikipedia.org/wiki/Respiratory_system): the organs used for breathing, the [pharynx](http://en.wikipedia.org/wiki/Pharynx), [larynx](http://en.wikipedia.org/wiki/Larynx), [trachea](http://en.wikipedia.org/wiki/Vertebrate_trachea), [bronchi](http://en.wikipedia.org/wiki/Bronchi), [lungs](http://en.wikipedia.org/wiki/Lung), and [diaphragm](http://en.wikipedia.org/wiki/Thoracic_diaphragm). - [Urinary system](http://en.wikipedia.org/wiki/Urinary_system): [kidneys](http://en.wikipedia.org/wiki/Kidney), [ureters](http://en.wikipedia.org/wiki/Ureter), [bladder](http://en.wikipedia.org/wiki/Urinary_bladder) and [urethra](http://en.wikipedia.org/wiki/Urethra) involved in fluid balance, electrolyte balance and excretion of urine. - [Vestibular system](http://en.wikipedia.org/wiki/Vestibular_system): contributes to our balance and our sense of spatial orientation.