Department of pathology, university of maryland, school. Mechanisms of cell injury in the killing of cultured hepatocytes by bromobenzene. Mechanisms of hypoxic and ischemic injury springerlink. It is associated with two separate pathophysiological processes with distinct molecular and physiological antecedents. Irreversible cell injury can be recognized by changes in the appearance of the nucleus and rupture of the cell membrane. Identify the three major mechanisms of cell injury and. Vascular endothelial cells normally perform several key homeostatic functions such as keeping blood fluid, regulating blood flow, regulating macromolecule and fluid exchange with the tissues, preventing leukocyte activation, and aiding in immune surveillance for pathogens. The first change, of course, is loss of atp production by mitochondria. Ischemic injury is caused by diminished or absent blood flow.
If the adaptive capability is exceeded or if the external stress is inherently harmful, cell injury develops fig. General principles cell response to injury is not an allornothing phenomenon response to a given stimulus depends on the type, status, and genetic makeup of the injured cell cells are complex interconnected systems, and single local injuries can result in multiple secondary and tertiary effects. Control of the rate of cell death relative to the rate of cell division maintains organ integrity and physiological homeostasis. Cell death is valuable for the organism because it removes terminally injured or unwanted cells that utilize valuable substrates and nutrients. Sep 21, 2017 what are the similarities between reversible and irreversible cell injury. Mechanisms of cell injury by activated oxygen species. Mechanism and therapies of oxidative stressmediated cell. Mechanical trauma, extremes of temperature burns and deep cold, sudden changes in atmospheric pressure, radiation, and electric. Cells that utilize molecular oxygen generate highly reactive oxygenderived free radicals. King md, phd, in elseviers integrated pathology, 2007. Cell injury, cell death, and adaptations new age medical. Cell injury cell injury results from a disruption of one or more of the cellular components that maintain cell viability. Identify the three major mechanisms of cell injury and their distinguishing characteristics. Cell injury often starts with atp depletion this can happen with several types of injury, including hypoxic injury and chemical injury.
Reversible injury may require cellular adaptation but the cell survives. The mechanism of injury and recovery of the cell science. For example, a heart muscle fiber stops beating within 60 seconds after cessation of blood flow. Within certain limits injury is reversible, and cells return to a stable baseline.
Adaptation and reversible injury patterns of tissue. Additionally, hypoxic injury, reactive oxygen species, free radicalinduced. May 15, 2018 in this video we have discussed the different mechanisms of cell injury. Mechanisms of cell injury the structure and metabolic functions of the cell are interdependent. 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. When cells are injured, one of two patterns will generally result. At the cellular level, there are many processes that can lead to. Cellular hypoxia and reoxygenation are two essential elements of ischemiareperfusion injury.
Cell cultures are useful tools to study the mechanisms involved in cell death following hypoxia or ischemia. For example, sinusoidal endothelial cell apoptosis is observed in ischemiareperfusion injury, and failure of activated stellate cell apoptosis promotes. Discriminate cell adaptation, reversible cell injury and irreversible cell injury cell death based on etiology, pathogenesis and histological and ultrastructural appearance. Request pdf mechanism of liver cell injury liver cell death is triggered by a number of insults arising from the external environment or from within the cell. Ischemic and hypoxic injury are the most common types of cell injury in clinical medicine and have been the subject of numerous investigations in humans, experimental animal models, and cell culture systems. In this video we have discussed the different mechanisms of cell injury. 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. Normal cell destruction followed by replacement proliferation such as in intestinal epithelium. Pdf on aug 1, 1996, j p cobb and others published mechanisms of cell injury and death find, read and cite all the research you need on. A cell exposed to persistent sublethal injury has limited available responses, the expression of which we interpret as evidence of cell injury. They have the ability to resist these different external and internal stress stimuli. Cell injury list of high impact articles ppts journals. Cellular adaptation cellular atrophy and hypertrophy. Evidence for the participation of activated oxygen species and the resulting peroxidation of lipids in the killing of cultured hepatocytes by aryl halides.
Chapter 1 mechanisms of injury introduction trauma starts with the transfer of energy to the body from an outside force. Introduction cell injury is defined as a variety of stresses a cell encounters as a result of changes in its internal and external environment. Although disease processes are multifarious, the basic categories of insult which can precipitate the mechanisms discussed in cell injury biochemistry are few. Oct 16, 2009 in this case the mechanism involves a spinal cord action of prostaglandins harvey et al. Appears whenever cells are incapable of maintaining ionic and fluid homeostasis.
Extremely important common cause of cell injurycell death. In this case, it is an orderly process and part of normal. Both are caused by chemical, physical or biological agents. Pdf on aug 1, 1996, j p cobb and others published mechanisms of cell injury and death find, read and cite all the research you need on researchgate.
The transfer of kinetic energy may be blunt or sharp in nature. These conditions permit study of cells reaction to the trauma under specific conditions. The free radical theory stating that lung cells poison themselves by producing an endogenous excess of reactive oxygen species ros within. Cells undergo many adaptations in response to different environmental, physiological and chemical stimuli. Terms in this set 29 what is the most common immediate cause of cell injury and what are the mechanisms. Types of adaptation pathologic adaptations may share the same underlying mechanisms, but they provide the cells with the ability to survive in their environment and perhaps escape injury. Acquired causes of cell injury further categorized as given, a. The major characteristics of cell injury are atp depletion loss of mitochondrial atp and decreased atp synthesis which results in cellular swelling, decreased protein synthesis, decreased membrane transport and lipogenesis. The mechanisms underlying the processes described above involve.
Pathologic cell injury and cell death i mechanism of. What is the difference between reversible and irreversible cell injury. Characteristics and mechanisms of cell injury and cell death. Mechanism of irreversible cell injury the art of medicine. Injury or cell death impairs or prevents conduct of these activities, resulting in dysfunction. Feb 21, 2018 hey there everyone, in this video you will get knowledge about the pathogenesis of cell injury, reversible cell injury, irreversible cell injury and much more, so go and grab a short note for your.
Pathology, lecture 2, cell injury slides search search. Cell injury results when cells are stressed and can no longer adapt. Cell injury is any disruption, physical or chemical, that results in the loss of a cells or tissues ability to maintain homeostasis, in either a normal or adapted state. Mechanisms of endothelial dysfunction, injury, and death. 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, adaptation and death mit opencourseware.
This topic covers the mechanism of irreversible cell injury. 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. Cellular adaptation is a state that lies intermediate between the normal, unstressed cell and the injured. Cell death occurs when the severity of the injury exceeds the cell s ability to repair itself. Pdf mechanisms of cell injury and death researchgate. Nowadays, there are too many studies about apoptosis which also named as physiological cell death, going on.
Download as ppt, pdf, txt or read online from scribd. First manifestation of almost all forms of cell injury. Jun 11, 2015 this topic covers the mechanism of irreversible cell injury. Cell injury may be reversible sublethal or irreversible lethal. Apoptosis, which is one of the very important regulatory mechanism to control so many equilibrium lasting at organism, is stimulated by heat, radiation, hormonal failure, toxins and lack of growth factors. The main mechanism of injury in ischemia is hypoxia as described above. Thrombosis, artherosclerosis diminished o2 carrying capacity of blood, eg.
At the cellular level, there are many processes that can lead to necrosis. If you continue browsing the site, you agree to the use of cookies on this website. Sublethal injury apply knowledge of cellular physiology, metabolism, and macromolecular synthesis to discuss cellular and subcellular responses to sublethal injury or stress on cells. Evidence for the participation of activated oxygen species and the resulting peroxidation of lipids in. Cell death occurs when the severity of the injury exceeds the cells ability to repair itself. In the past, most research has concentrated on the mechanisms causing cellular injury during ischemia and on protective procedures designed to reduce development of ischemic injury. Adaptation and reversible injury patterns of tissue necrosis. Key difference reversible vs irreversible cell injury cells are the main functional and structural units of living organisms. Both reversible and irreversible cell injuries occur when stress acts upon cells. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Physiologic involution of cells in hormone dependent tissues endometrial shedding during mensuration endometrial shedding during mensuration regression of lactating breast after withdrawal of breastfeeding. These conditions permit study of cell s reaction to the trauma under specific conditions. The first page of the pdf of this article appears above. Identify the three major mechanisms of cell injury and their.
Cell injury, reversible and irreversible cell injury by dr prerna shrivastava career hub medical duration. Hypoxia is the most important cause of cell injury. Mechanisms of cell injury and death in hyperoxia role of. May 29, 2015 pathologic cell injury and cell death i mechanism of reversible cell injuries pathologic cell injury and cell death i mechanism of reversible cell injury we already know that cells are able to adapt to their surroundings when there is an increased amount of stress to overcome them, just as we will in all our medical exams. Co poisoning poisoning of oxidative enzymes, cyanide. To define and describe in general terms physiological adaptations, reversible and irreversible injury and cell death. General principles cell response to injury is not an allornothing phenomenon response to a given stimulus depends on the type, status, and genetic makeup of the injured cell cells are complex interconnected systems, and single local injuries can result in multiple secondary and tertiary effects cell function is lost far before biochemical and. Full text get a printable copy pdf file of the complete article 1. When cell death occurs in the living body, the term necrosis is used.
Cell injury occurs when the limits to an adaptive response adaptation have been exceeded or if the cells are not able to adapt. Adaptation, reversible injury, and cell deathcan be considered. Classic theories of disease attributed disease to imbalances or noxious effects of humors on specific organs. Cell response to injury is not an allornothing phenomenon. Causes of cell injury pathogenesis and morphology of cell injury. In addition to blunt and sharp mechanisms, there is the situation of thermal energy in the form of heat, cold, or chemical agent, which generates the heat or. Define and understand the morphologic patterns of lethal cell injury and the clinical settings in which they occur. Specifically, tissue injury induces spinal release of the prostaglandin, pge 2, which acts on ep2 receptors expressed by excitatory interneurons and projection neurons in the superficial dorsal horn. It is change in cells morphology and function in response to.
Ischemic injury also results in more rapid and severe cellular acidosis than pure hypoxic injury because the absence of blood flow causes the localized accumulation of cellular. Therefore, although an injurious agent may target a particular aspect of cell structure or function, this will rapidly lead to wideranging secondary effects. Cell injury is reversible up to a certain point, but if the stimulus persists or is severe enough from the beginning, the cell reaches a point of no return and suffers irreversible cell injury and ultimately cell death. In hypoxic injury, the sequence of cell injury and death is still yielding up its secrets. General principles cell response to injury is not an allornothing phenomenon response to a given stimulus depends on the type, status, and genetic makeup of the injured cell cells are complex interconnected systems, and single local injuries can result in multiple secondary and tertiary effects cell. Extremely important common cause of cell injury cell death.
Pathogenesis of cell injury reversible cell injury. We list these causes below and discuss several in greater detail in their own pages. When theres not enough atp around, the cell membrane pumps dont work well, and sodium and calcium accumulate inside the cell. Chu, md, phd associate professor of pathology university of pittsburgh school of medicine summer academy 2010. Cell injury, adaptation, and necrosis apoptosis and beyond wiley. The slide includes a transmural section of the left ventricle. In general, mammalian cells adapt to injury by conserving resources. The causes of cell injury, reversible or irreversible, may be broadly classified into two large groups. Mechanisms of neutrophilinduced liver cell injury during hepatic ischemiareperfusion and other acute in. This chapter will present an overview of how the pathologist views mechanisms of irreversible cell injury cell death, reversible cell injury, and the organisms response to both. Mechanical trauma, extremes of temperature burns and deep cold, sudden changes in atmospheric pressure, radiation, and electric shock. By which of the following mechanisms has her neoplasm primarily responded to therapy. Over the next 2 months, the lymphoma decreases in size, as documented on abdominal ct scans. Difference between reversible and irreversible cell injury.
Activated neutrophils contribute to vascular reperfusion injury, yet posthypoxic cellular injury occurs in the absence of inflammatory cells through mechanisms involving reactive oxygen ros or nitrogen species rns. Mechanism of liver cell injury request pdf researchgate. Depending on the cell type, oxidative dna damage can be coupled to cell killing through a mechanism related to the activation of poly adpribose polymerase. Cerebral edema is caused by a variety of pathological conditions that affect the brain. Cell injury it is change in cell s morphology and function in response to stress. This chapter will present an overview of how the pathologist views mechanisms of irreversible cell injury cell death, reversible cell injury, and the organisms. General mechanism of cell injury learn with flashcards, games, and more for free.
General mechanism of cell injury flashcards quizlet. Oxygen deprivation to tissue ischemia leading to a form of tissue damage termed an infarct is of notable clinical significance e. Causes include reduced blood flow ischemia, inadequate oxygenation of the blood, decreased blood oxygencarrying capacity. She is treated with a chemotherapeutic agent which results in the loss of individual neoplastic cells through fragmentation of individual cell nuclei and cytoplasm. Over the past decade, the nomenclature committee on cell death nccd has formulated guidelines for the definition and interpretation of cell death from. By manipulating the extracellular environment, conditions that closely mimic the conditions that are thought to occur in vivo can be produced.
1528 52 339 1336 649 858 1083 1156 1023 1209 694 91 1486 718 283 436 1174 1495 1480 580 1039 369 1187 1238 64 1248 827 902 15 534 1273 1412 251 205 42 1337 591