Search results
Results From The WOW.Com Content Network
Main article: List of systems of the human body. Nervous system in a human body. There are 11 distinct organ systems in human beings, [2] which form the basis of human anatomy and physiology. The 11 organ systems: the respiratory system, digestive and excretory system, circulatory system, urinary system, integumentary system, skeletal system ...
Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. [2] Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways.
Below the level of living systems, he defines space and time, matter and energy, information and entropy, levels of organization, and physical and conceptual factors, and above living systems ecological, planetary and solar systems, galaxies, etc. [3] [4] [5] Miller's central thesis is that the multiple levels of living systems (cells, organs ...
A gland is a cell or an organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. [1] A gland may also function to remove unwanted substances such as urine from the body. [2] There are two types of gland, each with a different method of ...
In animals, the plasma membrane is the outer boundary of the cell, while in plants and prokaryotes it is usually covered by a cell wall. This membrane serves to separate and protect a cell from its surrounding environment and is made mostly from a double layer of phospholipids , which are amphiphilic (partly hydrophobic and partly hydrophilic ).
All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus Dictyostelium. [2] [3] Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single ...
The pancreas is a major organ functioning as an accessory digestive gland in the digestive system. It is both an endocrine gland and an exocrine gland . [ 28 ] The endocrine part secretes insulin when the blood sugar becomes high; insulin moves glucose from the blood into the muscles and other tissues for use as energy.