Adaptive and compensatory processes Lecture Types of

Adaptive and compensatory processes Lecture

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

АTROPHY o Life-time volume contraction of the cells, tissues or organs, accompanied by decrease or cessation of their functions.

Аtrophy o o o Physiological Senile Pathological (local and general)

Physiological atrophy o o Аtrophy and obliteration of umbilical arteries Obliteration of arterial (Botallo`s) duct Sexual glands atrophy in aged people Thymus atrophy in pubertal period

Атрофия тимуса

Senile atrophy o o o atrophy of gonads, intervertebral disks, skin

Pathological general atrophy Cachexia Can be: 1. Аlimentary 2. Cancerous 3. Hypophysial 4. Cerebral 5. Cachexia in case of chronic infectious diseases o

Brown atrophy in liver

Types of local pathological atrophy 1. 2. 3. 4. 5. Dysfunctional atrophy (atrophy of skeletal muscles doe to fracture) In case of circulatory insufficiency (wrinkled kidney, atrophy of cells of brain cortex due to atherosclerosis) Due to compression – pressure atrophy (hydronephrosis, hydrocephaly, emphysema of lungs) Neurotic (atrophy of skeletal muscles) Under the influence of physical or chemical factors (atrophy of gonads, medullary hemopoiesis)

Neurotic atrophy

Neurotic atrophy

Emphysema of lungs

Hydronephrosis

Аtrophy due to compression (Hydronephrosis)

Аtrophy of bone marrow after irradiation

Atrophied muscle substitution by adipose tissue

Atrophy morphology 1. 2. 3. 4. 5. 6. 7. Consolidation of tissue structure Dehydration Decrease of cellular mass Cells volume contraction Destruction of collagenic fibers Accumulation of acidic products Appearance of lipofuscin (brown atrophy)

Hypertrophy Volume increase of the functioning tissue, ensuring the organ hyperfunction. Hyperplasia – quantity increase of the cells, intracellular structures, vessels, stroma components.

Types of hypertrophy o o Physiological Pathological Types of pathological hypertrophy o o Neurohumoral Hypertrophic overgrowth (false) Work, compensatory Vicarious (substitutional)

Neurohumoral hypertrophy (hyperplasia) appear due to endocrine glands dysfunction. o In case of ovarian dysfunction in the endometrium glands hyperplasia develops. o In case of atrophic processes in oothecas in the mammary glands of men hyperplasia of gland lobes develops (gynecomastia). o Adenohypophysis hyperactivity usually appearing due to adenoid tumor (adenoma) is accompanied by enlargement of organs and protruding skeleton (acromegalia).

Hyperplasia of the uterus mucous membrane

Hypertrophic overgrowth (false hypertrophy) o o It is very often observed in case of a chronic inflammation (for example on mucosas with polyps formation) and in case of limphokinesis breaks in legs and lymph congestion, leading to the connective tissue overgrowth (development of elephantiasis).

Work (compensatory) hypertrophy takes place in the heart, gastrointestinal (G. I. ) tract, urinary and other organs. o Hypertrophy in the heart develops in case of birth and acquired valvular affections, accompanied by stenosis of atrioventricular openings, in case of arterial hypertension, coarctation of aorta, lungs vessels sclerosis, etc.

Hypertrophy of the left ventricle of the heart

Hypertrophy of the myocardium

Vicarious hypertrophy is observed in case of the death of one of the pair organs (lungs, kidneys, etc. ) due to some disease or operation. Compensation of the failed function is provided by an increased work of the remaining organ that is subject to hypertrophy.

As is obvious from the above-stated, the compensatory and adaptive reactions are the major reactions of the entire organism, ensuring homeostasis preservation both in the normal and pathological states. These reactions are the basis of reliability of biological systems.

Regeneration, hyperplasia, restructuring, functions doubling, changing of biological reactions speed depend on environmental factors influence rhythm

Therefore, adaptation and compensation are directed only at disease containment and prolongation of the patients life