Adaptive and compensatory processes Lecture Adaptation It

Adaptive and compensatory processes Lecture

Adaptation It is a wide biological concept, including phylogenesis, ontogenesis, evolution, heredity and all forms of an organism functions regulations both in a normal and pathological states, that is an adaptation to the changing living conditions and the ability to survive.

Compensation It is a more particular concept, an example of adaptation. A combination of an organism reactions, appearing in case of injuries or diseases and directed at the restoration of the impaired functions.

Comparative description of adaptations and compensations Adaptive reactions Compensatory reactions Specific Individual Enclose both the health and disease Are characteristic only for a disease, being a component part of it Homeostatic (are realized on the basis of automation and autoregulation principles) Situational, reactions of «preserve yourself» type in case of injury There are no stages (phases) Have a phasic character Morphologically are represented by Morphologically are atrophy, hypertrophy represented by compensatory (hyperplasia), organization, hypertrophy (hyperplasia) reconstruction of tissue, work and vicarious hypertroph metaplasia, dysplasia

Stages of compensatory reactions Formation II. Fixation (compensations) III. Decompensations (energy exhaustion) I.

Types of compensations and adaptations 1. 2. 3. 4. 5. 6. 7. Regeneration Аtrophy Hypertrophy Оrganization Tissue restructuring Metaplasia Dysplasia

Regeneration Restoration of tissues, cells, intracellular structures after their physiological or pathological death

Levels of regeneration o o o Molecular Subcellular Cellular Tissue level System level Organ level

Моrphogenesis: o Proliferation o Differentiation

Regeneration forms o o o Cellular and intracellular Intracellular (universal)

Cellular regeneration o o o o Bones Epidermis Mucous membrane of gastrointestinal tract, respiratory tract, ureters, urinary bladder Loose connective tissue Hemopoietic system Lymphoid tissue Меsothelium

Cellular and intracellular regeneration o o o Liver Kidneys Pancreas Lungs Unstriped muscles Vegetative nervous system

Intracellular regeneration o o Cells of the brain and spinal cord Cardiac hystocytes

Types of regeneration Physiological o Reparative: restitution (identical tissue) and substitution (connective tissue) o Pathological - Disregeneration: mеtaplasia, dysplasia - Hyporegeneration - Hyperregeneration o

Physiological regeneration o o o Constant renewal of cells and intracellular structures throughout the life time Epithelium is renewed every few days In the heart and brain only intracellular regeneration takes place

Reparative regeneration o o o It is an intensive physiological regeneration in case of the cells and tissues injury Complete (restitution) – compensation of tissue defect, identical to died off tissue Incomplete (substitution) – tissue healing with a fibrous scar

Pathological regeneration o o It is a perversion of the regenerative process Derangement of the proliferation and differentiation phases Hyperregeneration Hyporegeneration

Меtaplasia - is a form of disregeneration, transfer of one tissue type to the other, related type (epithelium, connective tissue, cartilage)

Dysplasia Derangement of proliferation, epithelium differentiation with development of cellular atypia (precancerous condition)

Connective tissue regeneration o o o It is a granulation tissue Маcrо: juicy, red, fine-grained on the surface Мicro: consists of 3 components – multiple thin-walled neogenic vessels, cells (fibroblasts, fibrocytes etc. ), thin fibers of connective tissue

Regeneration of bone tissue 1. 2. 3. 4. Preliminary connective tissue callosity Preliminary callus Final callus Function restoration and bone restructuring

Регенерация слизистой оболочки кишки

Регенерация печени

Регенерационная гипертрофия миокарда

Regulation of regeneration o Humoral mechanisms o Immunological o Neural o Functional

Regularities of regeneration In children and young people – the more perfect regeneration In case of malnutrition – delayed regeneration 1. 2. § § avitaminosis C and D deficiency of paraplastic substance Innervation disorders – incomplete regeneration Derangement of hormonal regeneration Local factors 3. 4. 5. § § necrohormones trephones ultra-short waves mitogenetic rays Regeneration increase

Оrganization Substitution of necrosis area, tissue defect (wounds), thrombus by the connective tissue Encapsulation – a sort of organization

Character of the organizing substrates: o o o Encapsulation and organization of necrosis foci. Organization of thrombi, exudate, blood clots. Encapsulation of the foreign bodies and parasites.

Biological meaning: o o To localize the pathologic process, isolate it from surrounding tissue. Organization and encapsulation are developing through formation of granulation tissue.

Организация тромба

Forms of wound healing o o Immediate closing of epithelial effect Healing under scab – scratch (3 -7 days) First intention (10 -15 days) Second intention (traumatic inflammation → granulation tissue → epithelium regeneration → scarring)