How are the 11 organ systems connected to each other

Organ (biology)

A organ (from ancient Greekὄργανονórganon, German 'tool, sensory tool')[1] is a specialized part of the body made up of different cells and tissues. An organ is a delimited functional unit in a multicellular living being. An organ is based on its own organ structure and goes through a specific organogenesis. The interaction of the organs realizes the organism. Organs are functionally connected directly to one another through organ systems. Organs are based on the biological differentiation (“division of tasks”) of the cells of real multicellular cells.


Functional classification

A uniform assignment of certain functions to organs is often problematic, since many organs in different multicellular living beings can take on different tasks that are distributed over several organs in other living beings. An example of this is the gill of fish, which serves both for breathing and for excretion of substances and thus partially replaces the function of a kidney.

Organs in humans

Data based on the following comparative values: age: 20–30 years, lifespan: 70 years, height: 170 cm, weight: 70 kg and a body area of ​​1.8 square meters. (The sensory organs and the genital organs were not taken into account here.)

body partWeightproportion of
Muscles30.0 kg43,0 %
Boneless skeleton7.0 kg10,0 %
Skin and subcutaneous tissue6.1 kg8,7 %
Digestive tract2.0 kg2,9 %
liver1.7 kg2,4 %
red bone marrow1.5 kg2,1 %
brain1.3 kg1,8 %
both lungs1.0 kg1,4 %
heart0.3 kg0,43 %
both kidneys0.3 kg0,43 %
spleen0.18 kg0,26 %
thyroid0.02 kg0,03 %
total70 kg100 %

Plant organs

Under the term Plant organs one understands the individual functional, but not purely morphologically classifiable parts of a plant. Essentially, these are the various types of shoots, leaves and roots and their individual parts, as well as metamorphoses of the same.

Analogous to the functions of animal organs, the plant organs serve the main tasks

Stem axis



See also


  • Jörn Henning Wolf: The term “organ” in medicine. Broad history of its development. Munich 1971 (= New Munich contributions to the history of medicine and natural sciences, medical history series. Volume 3).

Web links

Individual evidence

  1. ^ Wilhelm Gemoll: Greek-German school and manual dictionary. Munich / Vienna 1965.