Irritability is ... Irritability and excitability

Irritability is the ability of the body or individual tissues to respond to the environment. It is also the ability of the muscle to contract in response to stretching. Excitability refers to a property of a cell that allows it to respond to stimulation or stimulation, for example, the ability of nervous or muscle cells to respond to an electrical stimulus.

The most important biological property

Irritability is in biology a property of tissues that can perceive internal or external interference and respond to it by transitioning into an excited state. Such tissues are called excitable and have a certain number of characteristic qualities. They include the following:

1. Irritability. This is when cells, tissues and organs are capable of responding to the intervention of certain stimuli, both external and internal.

2. Excitability. This is the quality of animal or plant cells, in which it becomes possible to change the state of rest to the state of physiological activity of the organism.

3. Conductivity. This is the ability to spread excitatory reactions. It depends on the structure of the tissue and its functional characteristics.

4. Memory is responsible for fixing the occurring changes at the level of molecules with the introduction of changes in the genetic code. This quality makes it possible to foresee the behavior of the organism in response to repeated interventions.

Irritability: definition and description

What is irritability? Is this property of the body the norm or is it rather a state of morbid excitability and excessive sensitivity of the organ or part of the body? Natural susceptibility is characteristic of all living organisms, tissues and cells, which, under the influence of certain stimuli, react in a certain way. In physiology, irritability is the property of the nervous, muscle or other tissue to react to stimuli. The ability to respond to changes in the physical or biological environment is the property of all life on Earth. Examples are the following: the movement of plants to light, the narrowing and dilatation of the pupil due to a change in the intensity of light and so on.

The etymology of the concept

The term comes from Latin irritabilitas. Irritability is the reaction of excitation to certain external factors. This term is used to describe physiological responses to stimuli, as well as pathological manifestations associated with excessive sensitivity. This concept should not be confused with irritability. This property can be demonstrated in behavioral responses to the environment, situational, sociological and emotional stimuli and manifested in uncontrollable anger, anger and a sense of frustration. As a rule, this quality is inherent only in people. Irritability is the property of all living things, including the animal and plant world.

Irritability and adaptation

All living organisms have the property of irritability. It is the ability of the body to perceive and respond to certain stimuli that can have both positive and negative effects. The plant usually tends to the side where there is more sunlight. Feeling warm, a person can remove his hand from a hot stove.

Closely related to the concept of "irritability" is the adaptation that is responsible for changes in the body in response to external influences. For example, the human skin darkens when exposed to intense sunlight. The term "adaptation" is often used to describe certain changes in populations that, as a rule, can not be transmitted to offspring and therefore are not evolutionarily significant. In addition, these changes are usually reversible. For example, sunburn will gradually disappear if the individual ceases to stay in the sun. Environmental conditions can also cause long-term changes in the genetic composition of the population, which will already be irreversible in individual organisms.

Basic concepts

Irritability refers to the ability of living organisms to react in a certain way to external influences by changing their form and certain functions. In the role of irritants are those environmental factors that can cause a response. In the course of evolutionary development, tissues have been formed which have an increased level of sensitivity due to the presence of special receptors in the cells. Such susceptible tissues include nervous, muscular and glandular tissue.

Interrelation of irritability and excitability

Irritability and excitability are inextricably linked. Excitability refers to such a property of highly organized tissues as a reaction to external influences by changing physiological qualities. In the first place, excitability will be the nervous system, followed by muscles and glands.

Types of irritants

There are external and internal methods of intervention. External are:

1. Physical (mechanical, thermal, ray and sound). Examples can be sound, light, electricity.
2. Chemical (acids, alkalis, poisons, drugs).
3. Biological (bacteria, viruses and the like). An irritant can also be considered food and an individual of the opposite sex.
4. Social (for people it can be ordinary words).

As for the internal, it is about substances that are produced by the body itself. It can be hormones and other biologically active components. On the strength of the impact, three groups are distinguished: subthreshold - those that may not cause a response, threshold - moderate intensity interventions - and superthreshold, causing the strongest reaction.