Adaptation and Compensation - PDF

# 9. Adaptation. Compensation - is a pathobiological concept, which is uniting all processes of vital activity of the organisms with the environment and directed at the preservation of species. - is a particular kind of the adaptation at an illness, directed on restoration or correction of the brok...

# 9. Adaptation. Compensation - is a pathobiological concept, which is uniting all processes of vital activity of the organisms with the environment and directed at the preservation of species. - is a particular kind of the adaptation at an illness, directed on restoration or correction of the broken functions & structures ## Compensation - It is individual concept - In medicine adaptation and compensation supplement each other. - 2 forms of adaptation and compensation supplement each other: **intracellular** and **extracellular** ### Compensatory adaptation - It realizes on molecular, subcellular, cellular, tissular, organ, systemic levels. - There are the following compensatory and adaptive processes: - Regeneration - relapse of damaged or missing tissue by increase in cell number - Metaplasia - replacement of differentiated somatic cell type with a different and sometime none somatic cell - Hyperplasia - increased cell number in size of an organ - Hypertrophy - enlargement of a tissue by increase in size of rely. - Atrophy - decrease in size of rely - Organization - presentation of the cell in a specific organ - Dysplasia - presence of abnormal cells in an organ or tissue ## 1. Regeneration - is restoration of both structures & functions of tissues to replace the dead - It is the restoration of the structural elements of tissues to replace the dead - There are following types of regeneration: - Physiological - is restoration of tissues - to - die to normal physiological condition. - Reparative - is restoration of tissues to replace the died as a result of diseases. ### (b) Reparative regeneration - It maybe - Complete (restitution)/restorative hypertrophy - Incomplete (substitution) #### Complete reparative regeneration - Is a replacement of defect by a tissue identical to the perished. - A cell form of regeneration predominant at this process #### (i) Incomplete regeneration - Is replacement of defect by corrective tissue (brahnencapsulation) - This is termed **organization.** - Restoration of the lost function is achieved due to a highly corrective part of body or a tissue - A intracellular form of regeneration predominant at this process. #### Regerative capacity: - Restoration of structure & function can be realized due to cellular & intracellular form of regeneration. - The cells of the body can be divided into 5 groups - Labile - Stable - Permanent - on the basis of their regeneralive capacity. #### Granulation Tissue. - Granulation tissue ( 7-14 days) is an example of complete regeneration of corrective tissue. - It is consist of: - Numerous neogenic blood capillaries (fibroblasts) - ( young Cyfibroblasts? Corrective tissues) - New cells of the connective tissue. - On gross examination, granulation tissue is soft & fleshy, it appears pink & granular. - A loose interstitial substance is situated between the cells ( young fibers) - The collagen content of granulation tissue progressively increases with the time. ( bit of the rumorous capillaries ) - Blood reparative regeneration ( happen after blood loss ) - The appearance of blood differs from physiological in great intensing and the repteretive needs for extra-medullary hematopoiesis in the spleen, tivar, lymph nodes, mucous membranes and adipore tissues. - Blood Erythrorytes form at the long tubular bones #### Bone regeneration: ##### (1) In uncomplicated fractures - It occurs by primary bone fusion. - First, a preliminary connective tissue callus is framed. - Then it is replaced by a precursory bone & final bore callus. ##### (2) With complicated, comminuted fractures - It occurs by secondary bone fusion. - First, a preliminary bore-cartilaginous callus is formed & then the final bore callus. ##### Bone regeneration: - uncomplected bore callus - preliminary connective tissue collus - final bore callus ##### Phases: - preliminary bore-cartilaginous callus - final bone collus **Healing process (according to Darydovsky).** - Healing by direct closing of epithelial integument - It is simple healing due to crawl of epithelium on a superficial defect. - Healing by scab - Small defect fills with clotted blood, which forms a scab. - Healing by first intention (primary union) - For clean incised wounds. - Healing by second intention (Secondary union) - For clean incised wounds. - When foreign material is present almost of wound marigrs. - When necrosis is extensive. - When lacerations with in ability to apposit of wound marigrs. - When infection occurs. - Due to complicated, wounds. ### Pathological regeneration. - It develops when are violated of phases of proliferation & differentiation of cells. - It is includes, - Hyper-regeneration. - Hypo - regeneration - - Meta plasia. #### (i) Hyper – regeneration - Is showed in superfluous (excessive) formation of regeneration tissue. - Negative pressure contributes to the convergence of artikala surfaces approaching each other. - Bore fragment approaching each other. - An example of hyper-regeneration of connective tissue is keloid scar, hyper-regeneration is a trophic ulcer that does not heal for a long time. - An example of hyper-regeneration of bone tissue is exostosis, hypo-regeneration is false joint. #### (ii) Hypo- regeneration. - Is showed in scanty formation of regenerating tissue. ## II Meta plasia. - Is transformation of one tissue kind in another. In within scope of one embryonic leaf. - Certain functional organs or tissues may adopt to a disease process by increasing cell mass - There are 2 mechanisms of increasing - Hyperplasia. - Hyper- trophy. #### (1) Hyperplasia :- - Is an increase in the size of an organ or trssue due to an increase in the number of cells #### (1) Hyper trophy - Is an increase in the size of an organ or trssue due to increase in the site of existing cells accompanied by an increase in their functional capacity. - An increase in functional cell mass through hyper-trophy & hyper-plasia may be physiological - Under the influence of endocrine stimulation in pregnancy , breast epithelial cells and myometrial smooth muscle cells to increase in size & number. - Increased cell mass in a tissue can result from pathological stimulation. ## Hypertrophy. - There are following kinds of hyper-trophy. - Work - Vicarious - Neurohumoral - Hyper trepic overgrowths. #### Hypertrophy of heart - Normal thickness of left ventricle wall = 0.8-12m - The heart increase in weight & in size due to thickening of the left ventricular wall at the arterial hypertension. - The ventricular chambers can be diminished con centric hyper-trapry or dilated (accentric hypertrophy) - The first one is compensatory hypertrophy; the second is hypertrophy on the stage of decompensation. - Cardiomyocells are increased and their nukelel also increased. - There are many blood vessels in the enlarged stroma. ### dcp he hormonal (reuro-humoral) hypertrophy :- - It is not compensatory. - It may not occur uniformly throughout a tissue, only 'nodules' of normal tissue, giving rise to the term nodulur hyperplasia. - Excessive cell growth develop between areas of normal tissue. - They are the most common in prostate gland, thyroid gland, adrenal gland & the breast. #### Working hypertrophy: - It develops with increased work of the organ in physiological conditions and pathology - Most often occurs in the heart, skeletal muscles, stomach, urinary bladder, and in the stomach wall - Occurs with pylorik stenosis - Occurs in the heart - Occurs with prostate adenarna, urinary bladder wall - urolithiasis #### Hypertrophy of prostate gland 3- - Shows the enlarged prostate gland & dilated urinary bladder. - The cut surface shows the nodules, which are the result of nodular hyper plasia of the glands located around the membranous part of the prostatre urethra. - This problem in elderly men resulting in compression of the prostatic urethra & difficulty with micturition. #### Glanduler hyperplasia of the endometrium. - Shows greatly thickered endometrium, which is characterized by an increase in the number of cells in each gland. - The gland have "twisty shape". - Some of them have dilated lumen & appearance. of cyst. - The gland epithelium proliferates, the stroma is reach by cellulor elements. It is proliferates too. - The cause of glandular hyper-plasia of the endometrium is ovarian dysfunction. - It is manifested by dysfunctional uterine bleeding. - It may be due to the development of tumors in a woman’s ovaries that produce estrogor. - Most often develops with the natural extinction of ovarian function in the pre-moropausal & menapausal periods. #### Vicarious hypertrophy & hypoplasica of kidney - - shows/2 Kidneys called as vicarious (substitution - It has compensatory furctron) - One of them ander developed, small. - It has compensatory furctron - It has compensatory furctron - Loss of function of this kidney is compensated for by the other which undergoes hypertrophy. Cleading to enlargment) & takes on double the workload. #### + Working hypertrophy - The areters and pelvis of the kidney are dilated & overflowing with arine. - This is Called hydro-uretero nephrosis. - The substance of the kidneys is narrowed. Catrophy from pressure). ## IV. Atrophy. - is a decrease in the sire of a tissue or an orgar, resulting from a decrease in the site of individual cells composing the tissue with decrease of their function. - Atrophy has adaptive function in to a live organism. - There are following types of atrophy's - physiological - Pathological - General (cachexia) - Local. #### Types of general atrophy :- - alimentary - Cancerous - pituitary - Cerebral - due to Chronic infections (TB, brucellosis, dysentery) - At Cachexia the liver, heart, skeletal muscle s decrease in the site & have macroscopically (evident) brown coloration (brown atrophy). - Bez of lipotusin pigments #### Types of local atrophy: - dysfunctional Catrophy of disu) - Nutritional (oxygen deprivation - Denervation. atropty (lack of nerve stimulation in peripheral muscles from injung to motor nerves) - Pressure atrophy - Under the influence of physical and chemical factors - Hydrocephalus & hyodronephrosis are the examples of pressure atrophy. #### Hydrocephalus - Shows the brain with dilation of the cerebral ventriculor cavities & thinred white matter. & Cortex. - The obstruction of the CSF drainage pathways leads to increase in GSF volume within the brain, to accumulation of Cerebro Spinal fluid in ventriculor Cavities, to prolonged compression of brain tissue and to development of pressure atrophy of the cortex of brain #### Hydronephrosis - The kidney is enlarged - There is severe loss of renal parenchyma around a grossly dilated renal pelvicalyceal system. - The cortex & medulla decreased. ## IV Metaplasia - Is an abnormality of cellular differentiation in which one type of mature cell is replaced by a different type of mature cell in scope of one Ambryoric leaf. - Commonly involves the epithelium. - Metaplasia most commonly involves the epithelium. #### + In squamous metaplasia - The most common type of epithelial metaplasia - Non squamous pseudostratifred columnar or cuboidal epithelium is replaced by a normal appearing stratified squamous epithelium. - It is common th the endocervix and the bronchial mucosa. #### + Glandular metaplasia - Occurs in the esophagus where the normal squamous epithelial is replaced by a glandular, mucus secreting epithelium (neither gastric or intestinal in type), usually as a result of acid reflex into the esophagus. - Metaplasia may occur in the stomach & intestire where replacement of gastre mucosa with intestinal mucosa. - Metaplasia may be in Connective tissue. - eg. Areas of fibrous tissue exposed to chronic trauma may form bone (osseous metaplasia) - Metaplasia is a pre-Carrerous process - Squamous carcinoma develops in metaplastic squamous epithelium in the branchus and adrenocarcinoma may arise in the esophagis from metaplastic glandular epithelium.