88. Adaptation, compensation: definition of concepts, classification, stages of development of compensatory processes.

Adaptation is a broad biological concept that unites all the processes of vital activity, thanks to which the relationship of the organism with the external environment is carried out. Adaptation is aimed at preserving the species, therefore it covers both health and disease.

Compensation is a particular manifestation of adaptation to correct functional disorders in case of illness, to "save oneself" in a critical situation.

COMPENSATION is aimed at correcting impaired function in case of illness. The compensatory process is staged, there are three phases in it: becoming. consolidation and exhaustion. The compensation phase is characterized by the inclusion of all structural reserves and a change in the metabolism of the organ (system) in response to pathogenic effects. In the consolidation phase, compensatory capabilities are revealed most fully: there is a restructuring of the structure and exchange of the organ (system), ensuring their function under conditions of increased load. This phase can last a very long time (for example, compensated heart disease, compensated cirrhosis of the liver). It should be remembered that the optimal disclosure of the compensatory reaction and normalization of impaired functions do not always mean recovery, but often represent only a period of latent course of the disease, which may unexpectedly come to light under unfavorable conditions for the patient.

Morphologically, compensation is manifested mainly by hypertrophy. At the same time, the organs increase in size, but retain their configuration. The organ cavity either expands (eccentric hypertrophy) or decreases (concentric hypertrophy). Structural and functional changes are observed in the cells of the hypertrophied organ, indicating an increase in the intensity of metabolism. The enhanced function of the hypertrophied organ occurs due to an increase in the number of its specific intra-cellular formations, and in some cases this process unfolds on the basis of pre-existing cells and leads to an increase in their volume (hypertrophy), in others it is accompanied by the formation of new cells (cellular hyperplasia.

89. Atrophy: definition of the concept, types, macro- and microscopic changes in organs, examples of diseases.

1) Atrophy is a lifetime decrease in the volume of cells, tissues, organs with a decrease or cessation of their function.

Classification:

1. Physiological atrophy

2. Pathological atrophy: a) local pathological a. b) general pathological a.

2) Causes of physiological atrophy: age-related atrophy of the thymus gland, gonads, bones, intervertebral cartilage due to a decrease in their functional load or changes in neuro-humoral regulation

Causes of pathological atrophy:

a) general: 1. starvation or severe metabolic disorders (alimentary exhaustion) 2. toxic effect of the tumor on the body (cancerous cachexia) 3. Simmonds disease (pituitary cachexia) 4. hypothalamus lesion (cerebral cachexia) 5. severe chronic infections (tuberculosis, chronic dysentery)

b) local: 1. organ inactivity (atrophy of limb muscles in case of bone fracture) 2. circulatory insufficiency (myocardial atrophy in atherosclerosis of the coronary arteries) 3. tumor pressure, aneurysm, exudate (atrophy of the renal parenchyma in violation of urine outflow - hydronephrosis) 4. violation of tissue innervation 5. exposure to physico-chemical factors (prolonged use of GCS  atrophy of the adrenal cortex)