acid–base homeostasis
All living things depend on water. Life consists of a highly complex series of chemical reactions occurring in aqueous media. Among the most important factors in the composition of these ...
adjustment
Change or adaptation within a system that serves to accommodate the factor(s) that are promoting the change and produce a new equilibrium. A system changes when it is forced to, otherwise it tends to ...
autonomic nervous system
That part of the nervous system that controls and regulates involuntary body functions (e.g. digestion, heart rate, and temperature regulation). It is divided up into the sympathetic and ...
body fluids
A term that includes blood, tears, sweat, serous and mucous secretions from all bodily orifices, saliva, urine, and semen. In clinical usage, the term refers to body fluids that can transmit ...
breathing
(breeth-ing)the alternation of active inhalation of air into the lungs through the mouth or nose with the passive exhalation of the air. Breathing is part of respiration and is sometimes called ...
calcium
(kal-siŭm)a metallic element that is an important constituent of bones, teeth, and blood. It is also essential for many metabolic processes, including nerve function, muscle contraction, and blood ...
Claude Bernard
(1813–1878)French physiologist who formulated the principle of homeostasis, the physiological self-corrective mechanism that “automatically” seeks to restore the normal internal bodily environment ...
closed-loop control
In cybernetics, a control process in which a system's output is returned to its input as feedback, this being characteristic of controlled processing and all homeostatic processes. Compare open-loop ...
control mechanism
Any mechanism that regulates a biological process, such as a metabolic pathway or enzyme-controlled reaction, or that helps to maintain the internal environment (see homeostasis). See also feedback.
cybernetics
The study of communications systems and of system control in animals and machines. In the life sciences, it also includes the study of feedback controls in homoeostasis.
drinking
Taking in water by mouth to quench thirst. Many aquatic animals take water in through the mouth, but this may play no role in homeostasis. True drinking applies to terrestrial animals that take in ...
excretion
The natural removal of metabolic waste products, water, mineral salts, and carbon dioxide from the body. It occurs through the kidneys, lungs, and sweat glands.
feedback
The process by which knowledge acquired from past experiences informs and alters actors' choices when they encounter similar situations. It is a central concept of cybernetics and information theory.
feeding
All behaviour that involves the obtaining, manipulation, and ingestion of food. Compare foraging.
glia
(neuroglia) n. the special connective tissue of the central nervous system, composed of different cells, including the oligodendrocytes, astrocytes, ependymal cells (see ependyma), and microglia, ...
glucostatic theory
A homeostatic theory of hunger, according to which the brain monitors the difference between the levels of glucose in the arteries and veins as an index of the rate of glucose removal from the blood. ...
hypothalamus
The region of the brain that controls the autonomic nervous system and links the nervous and endocrine systems of the body. See hypothalamo–pituitary–adrenal axis.
insulin
A hormone produced in the pancreas. It controls the levels of sugar in the blood. Diabetes mellitus is the production of too little or no insulin.
internal environment
The conditions that prevail within the body of an organism, particularly with respect to the composition of the tissue fluid. The concept of an internal environment was first proposed by the French ...
kidney
An organ that may have arisen in freshwater animals for the purpose of voiding excess water and that is concerned in modern forms with excretion and/or the retention of water.
