selective myocardial cell necrosis definition of selective myocardial cell necrosis in the Free Online Encyclopedia.

necrosis

1. the death of one or more cells in the body, usually within a localized area, as from an interruption of the blood supply to that part

2. death of plant tissue due to disease, frost, etc.

necrosis [nə′krō·səs]

(medicine)

Death of a cell or group of cells as a result of injury, disease, or other pathologic state.

Necrosis

the death within the living organism of individual organs or their component tissues or cells.

A necrosis is classified according to the pathological condition that causes it. Thus, frostbite and burns can cause traumatic necrosis; neurotropic necrosis arises with syringomyelia and the nervous form of leprosy; infarcts and gangrene are associated with circulatory, or ischemic, necrosis; caseous necroses occurring in tuberculosis and syphilis are forms of septic necrosis; and fibrinoid necrosis associated with allergic diseases is a type of allergic necrosis.

Necrosis is accompanied by characteristic changes in the cell and in the intercellular substances. The nucleus shrinks and coagulates, a process known as pycnosis, and the cytoplasm breaks up into clumps. The cell eventually lyses, that is, it degenerates and dissolves. The lysis is due to the activation of the lysosomal hydrolytic enzymes, such as ribonuclease, deoxyribonuclease, and acid phosphatase. The activation of the lysosomes occurs as a result of an increase in the permeability of the cell membranes, changes in the osmotic equilibrium, and acidosis—an abnormal increase in the intracellular hydrogen-ion concentration. Fibrinoid changes appear in the connective tissue, and nerve fibers become fragmented and disintegrate into clumps.

The clinical and morphological manifestations and further consequences of necrosis depend on the localization and distribution of the necrosis and on the mechanisms and conditions of origin. The following types of advanced necrotic conditions can develop: dry necrosis, such as Zenker’s degeneration of infected muscles; colliquative, or liquefactive, necrosis, which occurs for example, when a focus of softening arises in the brain in response to cerebral hemorrhage; gangrene; and bed sores. Necrotic tissue tears away; then, either connective tissue grows through it or the necrotic tissue undergoes autolytic or purulent liquefaction. Finally, the necrotic tissue becomes encapsulated and petrified.

The two most serious consequences of necrosis are a loss of function owing to the death of the structural elements of the necrotic tissues or organs and poisoning caused by the actual presence of a necrotic focus and by the inflammation that arises in response to this presence.

V. V. SEROV

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No references found	Selective Availability selective bidding Selective Breeding selective calling selective calling system selective circuit Selective Coating selective cracking Selective Dissemination of Information selective dump selective fading selective filling selective flotation selective forgetting selective fracturing selective fusion selective heating selective identification feature selective inhibition selective interference selective jamming selective laser sintering selective loading selective medium Selective Mining selective myocardial cell necrosis selective permeability selective photoelectric effect selective plating selective poisoning selective polymerization selective quenching selective radiator selective reflection selective replacement selective ringing selective scattering selective service selective solubility diffusion selective solvent Selective Telephone Communications selective trace selective transmission selectively doped heterojunction transistor selectivity selectivity coefficient selectivity diagram Selectivity of a Radio Receiver Selector selector channel selector pen	Selective Laser Coating Removal Selective Laser Melting Selective Laser Photocoagulation of Communicating Vessels Selective laser sintering Selective laser sintering Selective Laser Trabeculoplasty Selective leaching Selective leaching Selective Level Measuring Set Selective Level Meter Selective Liberal Arts Consortium selective lipectomy selective loading selective loading Selective Mass Storage Selective Maximal Combination Selective media Selective medium Selective medium Selective medium Selective medium selective memory selective mining Selective Mining Unit selective mobilization Selective Moving Target Indicator Selective mutism Selective mutism Selective mutism Selective mutism selective myocardial cell necrosis selective neck dissection Selective Negative Acknowledgment Selective Nerve Fascicular Degeneration Selective Nerve Root Block Selective Nerve Root Injection selective neuronal necrosis Selective Neuronal Potassium Channel Opener Selective non-catalytic reduction Selective Nulling of Dominant Interferers Selective oestrogen receptor modulator Selective Optimization of Side Activities Selective Orthogonal Least-Square Selective Packet Discard Selective Parallel Interference Cancellation Selective permeability Selective permeability Selective permeability Selective Phase Transfer selective photoelectric effect selective photothermolysis Selective Placement Coordinator Selective Plane Illumination Microscopy selective plating selective poisoning selective polishing selective polishing selective polishing selective polymerization

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Selective Availability

selective bidding

Selective Breeding

selective calling

selective calling system

selective circuit

Selective Coating

selective cracking