Biological systems

A biological system is a complex network of biologically relevant entities. As biological organization spans several scales, examples of biological systems are populations of organisms, or on the organ- and tissue scale in mammals and other animals, the circulatory system, the respiratory system, the nervous system, etc.

On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways.

A biological system is not to be confused with a living system, which is commonly referred to as life. For further information see e.g. definition of life or synthetic biology.

These specific systems are widely studied within and out Human anatomy. "Human" systems are also present in many other animals.

blood to and from the body and lungs with heart, blood and blood vessels.

The notion of system (or apparatus) relies upon the concept of vital or organic function: a system is a set of organs with a definite function. This idea was already present in Antiquity (Galen, Aristotle), but the application of the term "system" is more reccent. For example, the nervous system was named by Monro (1783), but Rufus of Ephesus (c. 90-120), clearly viewed for the first time the brain, spinal cord, and craniospinal nerves as an anatomical unit, although he wrote little about its function, nor gave a name to this unit.

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