When cell death occurs in the living body, the term necrosis is used. Pathologic cell injury and cell death ii necrosis the art. Cell injury, cell death, and adaptations new age medical. Jun 11, 2015 this topic covers the mechanism of irreversible cell injury. We list these causes below and discuss several in greater detail in their own pages.
Reversible injury may require cellular adaptation but the cell survives. An example of hypertrophy would be a liver regeneration after partial hepatectomy b breast development at puberty c the uterus during pregnancy d the uterus during menstruation e a papillomavirus induced skin wart 2. Study 5 morphology of reversible cell injury flashcards from lisence a. This topic, necrosis, involves cell death that is done unintentionally by the cell. Hyperplasia is primarily operative in which of the following growth alterations a appearance of affected kidney in renovascular hypertension. Cellular injury during cardiac arrest is principally mediated by oxygen deprivation, but additional neurologic injury is incurred depending on associated factors such as concomitant toxic exposures such as carbon monoxide, metabolic stressors such as hypoglycemia, and freeradical production after restoration of blood flow in the socalled. Intestinal type intestinal metaplasia glandular morphology.
A wide variety of chemicals are can induce severe cellular injury. Cell injury it is change in cell s morphology and function in response to stress. Extremely important common cause of cell injurycell death. Mechanical trauma, extremes of temperature burns and deep cold, sudden changes in atmospheric pressure, radiation, and electric shock. Strayer emanuel rubin p athology is basically the study of structural and functional abnormalities that are expressed as diseases of organs and systems. Cell injury may be reversible sublethal or irreversible lethal. Too much stress exceeds the cells adaptive capacity. Necrosis is defined as a localised area of death of tissue followed by degradation of tissue by hydrolytic enzymes liberated from dead cells. Role of free radicals in disease causation and antioxidants in their prevention. A series of video tutorials discussing the pathology of cell injury and adaptations. Cell injury, adaptation and death mit opencourseware. Cell injury results from different chemical mechanisms that act on several cellular componentsamong these are depletion of atp mitochondrial damage influx of calcium and loss of calcium homeostasis accumulation of oxygenderived free radicals oxidative stress defects in membrane permeability cell injury results from different chemical mechanisms that act on several cellular components. Cell injury, cell death, and adaptations c h a p t e r c o n t e n t s c h1 a p t e r introduction to necpathology 1 overview of cellular responses to stress and noxious stimuli 1 cellular adaptations to apoptosisstress 3 hypertrophy 3 hyperplasia 4 mechanisms atrophy 4 metaplasia autopha5 overview of cell injury and cell death de6. Chapter 1 cellular adaptations, cell injury, and cell death 5 if the limits of adaptive response to a stimulus are exceeded, or in certain instances when the cell is exposed to an injurious agent or stress, a sequence of events follows that is loosely termed cell injury.
These alterations may be divided into the following stages. Mechanism of cell death in case of ionizing radiation. Mechanisms of cell injury and death 5 figure 1 electron micrographs of murine thymocytes from normal a, sham laparotomy and septic b, caecal ligation and puncture mice. In coronary arteries, myocardial contractility is reversed if circulation is quickly restored. Download as ppt, pdf, txt or read online from scribd. Leakage of cellular content causes inflammation which aims at getting rid f the dead necrotic tissue.
Define and understand the morphologic patterns of lethal cell injury and the clinical settings in which they occur. Pdf mechanisms of cell injury and death researchgate. At the cellular level, there are many processes that can lead to necrosis. All cells have efficient mechanisms to deal with shifts in environmental conditions. Although disease processes are multifarious, the basic categories of insult which can precipitate the mechanisms discussed in cell injury biochemistry are few.
The main mechanism of cell injury involves the formation of free radicals and examples include carbon tetrachloride ccl 4once widely used in the dry cleaning industry but now bannedand the analgesic acetaminophen ccl 4 is converted to the toxic free radical principally in the liver, and this free radical is the cause of cell injury. Mechanism of irreversible cell injury the art of medicine. Cell injury results when cells are stressed so severely that they are no longer able to adapt or when cells are exposed to inherently damaging agents. Irreversible cell injury can be recognized by changes in the appearance of the nucleus and rupture of the cell membrane. Within certain limits injury is reversible, and cells return to a stable baseline. Adaptation change in cell morphology and function in response to a stimulus. May 29, 2015 this is the second post in the series. Contrast ischemia in skeletal muscle tolerates 2 hours versus cardiac muscle tolerate 20. Acquired causes of cell injury further categorized as given, a. Cell adaptation, cell injury and cell death pathology. Production, morphology and ultrastructure process results in a dramatic increase in plasma membrane surface area compared to that of a resting platelet, and may be assisted by a. Learn vocabulary, terms, and more with flashcards, games, and other study tools. If ischemia or hypoxia is for short period of time, the cell can be reverting back to its normal condition which is known as rci.
Cell injury it is change in cells morphology and function in response to stress. Discriminate cell adaptation, reversible cell injury and irreversible cell injury cell death based on etiology, pathogenesis and histological and ultrastructural appearance. The stronger and the longer the stimulus, the larger the damage response to a given stimulus depends on the type, status, and genetic makeup of the injured cell. Causes include reduced blood flow ischemia, inadequate oxygenation of the blood, decreased blood oxygencarrying capacity.
Introduction cell injury is defined as a variety of stresses a cell encounters as a result of changes in its internal and external environment. Viral evolution, morphology, and classification discovery and detection of viruses viruses are infectious particles about 100 times smaller than bacteria and can only be observed by electron microscopy. Causes of cell injury the causes of cell injury range from the external gross physical violence of an automobile accident to subtle internal abnormalities, such as a genetic mutation causing lack of a vital enzyme that impairs normal metabolic function. I will talk about all the different mechanisms of necrosis, pyknosis and its variants, and the different morphological types of necrosis, including coagulation, liquefactive, fat. Adaptation and reversible injury patterns of tissue necrosis. The syllabus for cell injury and cell death covers the material to be presented at the lectures on. The causes of cell injury, reversible or irreversible, may be broadly classified into two large groups. If you continue browsing the site, you agree to the use of cookies on this website. Hypoxia is the most important cause of cell injury. Morphological expressions of cell injury ava19672vnb1 1994 the video tape defines and describes injuries sustained by cells when they. It also depends upon the organ which undergoes hypoxia. In certain cases the chemical is directly toxic to cellular components such as the plasma membrane or mitochondria, precipitating basic biochemical causes of cell injury see. Hypoxic ischemic injury, free radical induced, chemical injury, reversible, irreversible, ischemia reperfusion injury, free radical removal mechanisms, f.
If the adaptive capability is exceeded or if the external stress is inherently harmful, cell injury develops fig. Classic theories of disease attributed disease to imbalances or noxious effects of humors on specific organs. Notably, well focus in on the different types of necrosis that may occur in the body, their causes, and what. Injury may progress through a reversible stage and culminate in cellular death. Morphology of irreversible cell injury apoptosis necrosis. Cell response to injury is not an allornothing phenomenon. There may also be a switch of contractile proteins from adult to fetal or neonatal forms. Normal cell n o r m a l r e v e r s i b l e c e l l i n j u r y i r r e v e r s i b l e c c e l l i n j u r y n e r o s i s clumping of chromatin injury r ecov ry death lysosome rupture membrane blebs sw ole nm it ch dr a with amorphous densities swelling of endoplasmic reticulum and loss of. In this tutorial, i have discussed morphology of reversible and reversible cell injury follow me. Fatty change encountered in cells invloved in fat metabolism hepatocyte, myocardium.