Irritability is the ability of an organism or individual tissues to respond to the environment. It is also the ability of muscles to contract in response to stretching. Excitability is a property of a cell that allows it to respond to stimulation or stimulation, for example, the ability of nerve 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 going into an excited state. Such tissues are called excitable and have a certain number of characteristic qualities. These include the following:
1. Irritability. This is when cells, tissues and organs are capable of responding with 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 resting state to the state of physiological activity of the body.
3. Conductivity. This is the ability to spread excitatory reactions. It depends on the structure of the tissue and its functional features.
4. Memory is responsible for recording the changes that occur at the level of molecules with the introduction of changes in the genetic code. This quality makes it possible to predict the behavior of the body 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 painful excitability and excessive sensitivity of an organ or part of the body? Natural susceptibility is characteristic of all living organisms, tissues and cells, which react in a certain way under the influence of certain stimuli. In physiology, irritability is the property of a nervous, muscle or other tissue to respond to stimuli. The ability to respond to changes in the physical or biological environment is a property of all life on Earth. Examples are the following: the movement of plants toward light, the narrowing and expansion of the pupil due to changes in light intensity, and so on.
Etymology of the concept
The term comes from Latin irritabilitas. Irritability is a reaction of excitement to certain external factors. This term is used to describe physiological reactions 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 can be manifested in uncontrolled anger, anger and a sense of frustration. As a rule, this quality is inherent only to people. Irritability is a property of all living things, including the animal and plant world.
Irritability and adaptation
All living organisms have the property of irritability. This is the body's ability to perceive and respond to certain stimuli, which can have both positive and negative effects. The plant usually leans in the direction where there is more sunlight. Feeling the heat, a person can remove his hand from the hot stove.
Closely related to the concept of “irritability” is adaptation, which is responsible for changes in the body in response to external influences. For example, human skin darkens when exposed to intense sunlight. The term “adaptation” is often used to describe certain changes in populations that, as a rule, cannot be transmitted to offspring and therefore are not evolutionarily significant. In addition, these changes are usually reversible. For example, the tan will gradually disappear if the individual ceases to remain 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 is the ability of living organisms to respond in a certain way to external influences by changing their shape and certain functions. Environmental factors that can trigger a response are stimuli. During evolutionary development, tissues were formed that have an increased level of sensitivity due to the presence of special receptors in the cells. Such susceptible tissues include nerve, muscle, and glandular tissue.
The relationship of irritability and excitability
Irritability and excitability are inextricably linked. Excitability is a property of highly organized tissues such as a reaction to an external effect by changing physiological qualities. The nervous system will come first in terms of excitability, followed by muscles and glands.
Types of irritants
Distinguish between external and internal methods of intervention. External include:
- Physical (mechanical, thermal, radiation, and sound). Examples are sound, light, electricity.
- Chemical (acids, alkalis, poisons, drugs).
- Biological (bacteria, viruses and the like). Food and an individual of the opposite sex can also be considered a irritant.
- Social (for people it can be ordinary words).
As for the internal, here we are talking about substances that are produced by the body itself. It can be hormones and other biologically active components. According to the strength of the impact, three groups are distinguished: subthreshold - those that may not cause an answer, threshold ones - moderate-intensity interventions - and superthreshold ones that cause the most severe reaction.