A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is.
Organ and tissue systems
, the
cerebellum, the
spinal cord, and the
are the four basic components of the
nervous system.
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These specific systems are widely studied in human anatomy and are also present in many other animals.
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Respiratory system: the organs used for breathing, the Human pharynx, larynx, bronchi, and diaphragm.
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Digestion: digestion and processing food with , oesophagus, stomach, liver, gallbladder, pancreas, , rectum and anus.
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Cardiovascular system (heart and circulatory system): pumping and channeling blood to and from the body and lungs with heart, blood and .
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Urinary system: , , urinary bladder and urethra involved in fluid balance, electrolyte balance and excretion of urine.
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Integumentary system: skin, hair, fat, and nails.
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Skeletal system: structural support and protection with , cartilage, and .
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Endocrine system: communication within the body using made by such as the hypothalamus, pituitary gland, pineal body or pineal gland, thyroid, parathyroid and , i.e., adrenal glands.
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Exocrine system: various functions including lubrication and protection by such , mucous glands, and
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Lymphatic system: structures involved in the transfer of lymph between tissues and the blood stream; includes the lymph and the lymph node and lymph vessel. The lymphatic system includes functions including immune responses and development of antibodies.
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Nervous system: collecting, transferring and processing information with brain, spinal cord, peripheral nervous system and sense organs.
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Muscular system: allows for manipulation of the environment, provides locomotion, maintains posture, and produces heat. Includes skeletal muscles, smooth muscles and cardiac muscle.
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Reproductive system: the sex organs, such as ovary, , uterus, vagina, , testes, vas deferens, and prostate.
History
The notion of system (or apparatus) relies upon the concept of vital or organic function:
[Fletcher, John (1837). "On the functions of organized beings, and their arrangement". In: Rudiments of physiology. Part 2. On life, as manifested in irritation. Edinburgh: John Carfrae & Son. pp. 1-15. link.] 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 recent. 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.
[Swanson, Larry (2014). Neuroanatomical Terminology: A Lexicon of Classical Origins and Historical Foundations. Oxford: Oxford University Press. link . p. 489.]
The enumeration of the principal functions - and consequently of the systems - remained almost the same since Antiquity, but the classification of them has been very various,[ e.g., compare Aristotle, Bichat, Cuvier.][Bichat, X. (1801). Anatomie générale appliquée à la physiologie et à la médecine, 4 volumes in-8, Brosson, Gabon, Paris, link. (See pp. cvj-cxj).][Cuvier, Georges. Lecons d'anatomie comparée 2. éd., cor. et augm. Paris: Crochard, 1835-1846. link .]
The notion of physiological division of labor, introduced in the 1820s by the French physiologist Henri Milne-Edwards, allowed to "compare and study living things as if they were machines created by the industry of man." Inspired in the work of Adam Smith, Milne-Edwards wrote that the "body of all living beings, whether animal or plant, resembles a factory ... where the organs, comparable to workers, work incessantly to produce the phenomena that constitute the life of the individual." In more differentiated organisms, the functional labor could be apportioned between different instruments or systems (called by him as appareils).[R. M. Brain. The Pulse of Modernism: Physiological Aesthetics in Fin-de-Siècle Europe. Seattle: University of Washington Press, 2015. 384 pp., [5] .]
Cellular organelle systems
The exact components of a cell are determined by whether the cell is a eukaryote or prokaryote.
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Cell nucleus (eukaryotic only): storage of genetic material; control center of the cell.
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Cytosol: component of the cytoplasm consisting of jelly-like fluid in which organelles are suspended within
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Cell membrane (plasma membrane):
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Endoplasmic reticulum: outer part of the nuclear envelope forming a continuous channel used for transportation; consists of the rough endoplasmic reticulum and the smooth endoplasmic reticulum
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Rough endoplasmic reticulum (RER): considered "rough" due to the attached to the channeling; made up of cisternae that allow for protein production
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Smooth endoplasmic reticulum (SER): storage and synthesis of lipids and steroid hormones as well as detoxification
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Ribosome: site of biological protein synthesis essential for internal activity and cannot be reproduced in other organs
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Mitochondrion (mitochondria): powerhouse of the cell; site of cellular respiration producing ATP (adenosine triphosphate)
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Lysosome: center of breakdown for unwanted/unneeded material within the cell
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Peroxisome: breaks down toxic materials from the contained digestive enzymes such as H2O2(hydrogen peroxide)
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Golgi apparatus (eukaryotic only): folded network involved in modification, transport, and secretion
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Chloroplast: site of photosynthesis; storage of chlorophyll
See also
Further reading
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"Systems Biology: An Overview" by Mario Jardon: A review from The Science Creative Quarterly, 2005.
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target="_blank" rel="nofollow"> "Synthesis and Analysis of a Biological System" by Hiroyuki Kurata, 1999.
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Schmidt-Rhaesa, A. 2007. The Evolution of Organ Systems. Oxford University Press, Oxford.
