Homeostasis

homeostaticequilibriumimmunomodulationhomeostaticallyself-regulatingbalancehuman homeostasishomeostatic mechanismshomeostatic regulationhomeostatic processes
In biology, homeostasis is the state of steady internal physical and chemical conditions maintained by living systems.wikipedia
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Fluid balance

diuresiseuvolemicfluid
This dynamic state of equilibrium is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range).
Fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes (salts in solution) in the various body fluids are kept within healthy ranges.

Biology

biologicalBiological Sciencesbiologist
In biology, homeostasis is the state of steady internal physical and chemical conditions maintained by living systems.
Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis.

Organism

organismsflora and faunaliving organisms
In biology, homeostasis is the state of steady internal physical and chemical conditions maintained by living systems.
All types of organisms are capable of reproduction, growth and development, maintenance, and some degree of response to stimuli.

Nuclear receptor

nuclear receptorsnuclearmechanism
At the cellular level, receptors include nuclear receptors that bring about changes in gene expression through up-regulation or down-regulation, and act in negative feedback mechanisms.
In response, these receptors work with other proteins to regulate the expression of specific genes, thereby controlling the development, homeostasis, and metabolism of the organism.

Extracellular fluid

transcellular fluidextracellular fluid volumetissue fluid
Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity.
The ECF composition is therefore crucial for their normal functions, and is maintained by a number of homeostatic mechanisms involving negative feedback.

Walter Bradford Cannon

Walter CannonWalter B. CannonDr. Walter B. Cannon
The concept of the regulation of the internal environment was described by French physiologist Claude Bernard in 1865, and the word homeostasis was coined by Walter Bradford Cannon in 1926.
He coined the term fight or flight response, and he expanded on Claude Bernard's concept of homeostasis.

Thermoregulation

body temperaturethermoregulatethermoregulatory
This dynamic state of equilibrium is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range).
The internal thermoregulation process is one aspect of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment (the study of such processes in zoology has been called physiological ecology).

Human body

bodyhuman anatomyhuman physiology
However, a great many other homeostatic mechanisms, encompassing many aspects of human physiology, control other entities in the body.
They ensure homeostasis and the viability of the human body.

Claude Bernard

Bernard, ClaudeBernardClaude Bernard Award
The concept of the regulation of the internal environment was described by French physiologist Claude Bernard in 1865, and the word homeostasis was coined by Walter Bradford Cannon in 1926.
He originated the term milieu intérieur, and the associated concept of homeostasis (the latter term being coined by Walter Bradford Cannon).

Gland

glandsglandularglandular tissue
The control center responds to the signal by determining an appropriate response and sending signals to an effector, which can be one or more muscles, an organ, or a gland.
These glands often secrete hormones which play an important role in maintaining homeostasis.

Negative feedback

negative feedback loopnegative-feedbacknegative
At the cellular level, receptors include nuclear receptors that bring about changes in gene expression through up-regulation or down-regulation, and act in negative feedback mechanisms.
In biology, this process (in general, biochemical) is often referred to as homeostasis; whereas in mechanics, the more common term is equilibrium.

Human body temperature

body temperaturecore body temperaturenormal human body temperature
Other normal temperature variations include those related to the menstrual cycle.
Temperature control (thermoregulation) is part of a homeostatic mechanism that keeps the organism at optimum operating temperature, as the temperature affects the rate of chemical reactions.

Allostasis

allostaticallostatic changes
Apart from the internal regulation of temperature, a process called allostasis can come into play that adjusts behaviour to adapt to the challenge of very hot or cold extremes (and to other challenges).
Allostasis is the process of achieving stability, or homeostasis, through physiological or behavioral change.

Carotid sinus

Carotid sinus massagecarotid sinus reflexCarotid sinus stimulation
For instance, the arterial blood pressure in mammals is homeostatically controlled, and measured by stretch receptors in the walls of the aortic arch and carotid sinuses at beginnings of the internal carotid arteries.
The carotid sinus contains numerous baroreceptors which function as a "sampling area" for many homeostatic mechanisms for maintaining blood pressure.

Blood sugar level

blood sugarblood glucoseblood glucose level
Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Blood sugar levels are regulated within fairly narrow limits.
The body tightly regulates blood glucose levels as a part of metabolic homeostasis.

Blood pressure

systolic blood pressurediastolic blood pressurearterial blood pressure
For instance, the arterial blood pressure in mammals is homeostatically controlled, and measured by stretch receptors in the walls of the aortic arch and carotid sinuses at beginnings of the internal carotid arteries.
In the short term, blood pressure is regulated by baroreceptors which act via the brain to influence the nervous and the endocrine systems.

Shivering

Shivershivering thermogenesischills
The metabolic rate is increased, initially by non-shivering thermogenesis, followed by shivering thermogenesis if the earlier reactions are insufficient to correct the hypothermia.
When the core body temperature drops, the shivering reflex is triggered to maintain homeostasis.

Blood sugar regulation

glucose homeostasisblood glucose regulationblood sugar control
Blood sugar levels are regulated within fairly narrow limits.
Blood sugar levels are regulated by negative feedback in order to keep the body in balance.

Respiratory center

ventral respiratory groupdorsal respiratory grouppontine respiratory group
Control centres include the respiratory centre, and the renin–angiotensin system.
The respiratory centre is responsible for generating and maintaining the rhythm of respiration, and also of adjusting this in homeostatic response to physiological changes.

Peripheral chemoreceptors

peripheral chemoreceptorperipheralaortic and carotid bodies
The partial pressure of oxygen and carbon dioxide in the arterial blood is monitored by the peripheral chemoreceptors (PNS) in the carotid artery and aortic arch.
As for their particular function, peripheral chemoreceptors help maintain homeostasis in the cardiorespiratory system by monitoring concentrations of blood borne chemicals.

Hormone

hormoneshormonalprohormone
For instance the signal (be it via neurons or hormones) from the sensor to the effector is, of necessity, highly variable in order to convey information about the direction and magnitude of the error detected by the sensor.
Hormone signals control the internal environment of the body through homeostasis.

Hyperventilation

hyperventilatinghyperventilaterapid breathing
However, at high altitude (above 2500 m) the monitoring of the partial pressure of oxygen takes priority, and hyperventilation keeps the oxygen level constant.
The body normally attempts to compensate for this homeostatically but if this fails or is overridden, the blood pH will rise, leading to respiratory alkalosis.

Cannabinoid receptor type 1

CB 1 CB 1 receptorCB1
The cannabinoid receptor type 1 (CB1), located at the presynaptic neuron, is a receptor that can stop stressful neurotransmitter release to the postsynaptic neuron; it is activated by endocannabinoids (ECs) such as anandamide (N-arachidonoylethanolamide; AEA) and 2-arachidonoylglycerol (2-AG) via a retrograde signaling process in which these compounds are synthesized by and released from postsynaptic neurons, and travel back to the presynaptic terminal to bind to the CB1 receptor for modulation of neurotransmitter release to obtain homeostasis.
This forms a feedback loop between the positive and negative metabotropic receptors, which can maintain a relatively similar homeostasis with any neuron connected through an electrical synapse.

Cybernetics

cyberneticcyberneticiancybernetically
The term cybernetics is applied to technological control systems such as thermostats, which function as homeostatic mechanisms, but is often defined much more broadly than the biological term of homeostasis.

Vasodilation

vasodilatorvasodilatorsvasodilatation
The brain can regulate blood flow over a range of blood pressure values by vasoconstriction and vasodilation of the arteries.
Such vasoactivity is necessary for homeostasis (keeping the body running normally).