Apr 03, 2018 reversible cell injury general pathology animated usmle lecture dr bhanu prakash duration. In reversible cell injury, it is up to a certain point. 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. Within certain limits injury is reversible, and cells return to a stable baseline. Low levels of stress can cause reversible cell injury. Cell damage also known as cell injury is a variety of changes of stress that a cell suffers due to external as well as internal environmental changes. Irreversible cell injury denotes pathologic changes that are permanent and cause cell death, they cannot be reversed to normal state for example. Key concepts contd cell injury can be reversible or irreversible reversibility depends on the type, severity and.
However, cell replication proceeds in a human body at a rate of c. Summarize the cells response to reperfusion injury emphasizing how reperfusion can exacerbate injury produced by ischemia. Chuang,2 zhihong liu,1 and john cijiang he2 1research institute of nephrology, jinling hospital, nanjing university school of medicine, jiangsu, china. Both are caused by chemical, physical or biological agents.
In other words, exposure to the damaging stimulus prevents the cell from regulating its. Irreversible cell injury what are the similarities between reversible and irreversible cell injury. The pathogenesis of cell injury is discussed in great detail. This is the key difference between reversible and irreversible cell injury. Reversible cell definition of reversible cell by merriam. Discriminate cell adaptation, reversible cell injury and irreversible cell injury cell death based on etiology, pathogenesis and histological and ultrastructural appearance.
Barry has an area of skin that has turned a dark, reddishblack. When cell death occurs in the living body, the term necrosis is used. Lots of things happening in cell injury situations. Mechanisms and morphology of cellular injury, adaptation, and death. Cellular swelling hydropic change or vacuolar degeneration chronic reversible changes. May 20, 2016 this presentation helps you in understanding the basic concepts of cell injury. Notably, well focus in on the different types of necrosis. 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. Cell response to injury is not an allornothing phenomenon.
It also depends upon the organ which undergoes hypoxia. Here we are, looking at irreversible cell injury now. Cell damage is a variety of changes of stress that a cell suffers due to external as well as internal environmental changes. Amongst other causes, this can be due to physical, chemical, infectious, biological, nutritional or immunological factors. Furthermore, oxygen deficiency due to anemia, blunt force trauma, toxins, and drugs can all cause either reversible or irreversible injury to a cell and even an entire organ or tissue. A pathologist notes that a biopsy from the lung of living patients shows the morphologic changes indicative of irreversible injury and cell death. Fatty change encountered in cells invloved in fat metabolism hepatocyte, myocardium.
Mccance and huether 2014 explain, a reversible cell injury is the loss of adenosine triphosphate atp, swelling of cell, detachment of ribosomes, autophagy of lysosomes p. Mechanism of irreversible cell injury the art of medicine. First, there are clearly many ways to injure a cell, not all of them invariably fatal. Mar 19, 2020 a pathologist notes that a biopsy from the lung of living patients shows the morphologic changes indicative of irreversible injury and cell death.
Adaptation and reversible injury patterns of tissue necrosis. Now, we will discuss the different ways by which cells can actually become injured, and the mechanism by which the cells become injured. Study 5 morphology of reversible cell injury flashcards from lisence a. It is an intracytoplasmic accumulation of water due to incapacity of the cells to maintain the ionic and fluid homeostasis. Normal cell homeostasis reversible injury inherently injurious harmful, cell mild, injury develops fig.
Thus, cell death is a normal physiological process as well as a reaction to injury. Both reversible and irreversible cell injuries occur when stress acts upon cells. Which of the following is most likely responsible for cell death in a living body. Define and understand the morphologic patterns of lethal cell injury and the clinical settings in which they occur. To define and describe in general terms physiological adaptations, reversible and irreversible injury and cell death. Irreversible cell injury results in complete cell death and normal cellular conditions cannot be achieved even if the stress is relieved.
Depending on the intensity of the nocive factor and length of its action, cell injury may be reversible and irreversible. Fatty change occurs in hypoxic injury and various forms of toxic or metaplastic injury manifested by appearance of large or small lipid vacuole in the cytoplasm occur in cells involved and dependant on fat metabolism such as hepatocytes and myocardial cells injured cells may show increased esinophilic staining which. When cells adapt to injury, their adaptive changes can be atrophy, hypertrophy, hyperplasia, or metaplasia. This lesson will discuss the different causes and types of irreversible cell injury.
Jun 11, 2015 this topic covers the mechanism of irreversible cell injury. 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. Full text get a printable copy pdf file of the complete article 2. Reversible injury definition of reversible injury by. Two patterns of reversible cell injury can be recognized under the light microscope. Homeostasis is altered but there could be a recovery and return to normal when the stressor or injurious stimuli are removed. Study 101 i reversible and irreversible injury flashcards from jessica t. Cell injury it is change in cells morphology and function in response to stress. Contrast ischemia in skeletal muscle tolerates 2 hours versus cardiac muscle tolerate 20. What is the difference between reversible and irreversible. Cell injury may be reversible sublethal or irreversible lethal. I reversible and irreversible injury pathology vpa5341.
In coronary arteries, myocardial contractility is reversed if circulation is quickly restored. One must distinguish atrophy of an organ from cellular atro phy. Within certain limits, injury is reversible, and cells return to a stable baseline. Huether s 2014 discuss and contrast reversible and. Glomerular endothelial cell injury and cross talk in diabetic kidney disease jia fu,1 kyung lee,2 peter y. Excess physiologic or pathologic stress may force the cell to a new steady state. Pathogenesis of cell injury reversible cell injury. You are asked to participate in a research project on myocardial infarctions in a rat model. Reduction in an organs size may reflect reversible cell at rophy or irreversible loss of cells.
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. Cell injury occurs when the limits to an adaptive response adaptation have been exceeded or if the cells are not able to adapt. Cell injury, adaptation and death mit opencourseware. Sep 08, 2009 reversible cell injury and cell adaptationspathology practical8th sept summaryravi a patel slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If stress factor is not removed on time irreversible injurycell death. Adaptation and reversible injury patterns of tissue. Ischemia is no o2 and nutrients and the buildup of waste due to interruption of blood flow. Vicious cycle intracellular increase after membrane damage. I reversible and irreversible injury pathology vpa5341 with arauz at ross university school of veterinary medicine. Reversible cell injury general pathology animated usmle lecture dr bhanu prakash duration.
The causes of cell injury, reversible or irreversible, may be broadly classified into two large groups. In early stages or mild forms of injury, the functional and morphologic changes are reversible if the damaging stimulus is removed. We discussed reversible cell injury and 1 type of cell death, namely necrosis, earlier in the posts. Cellular adaptations, cell injury, and cell death flashcards at proprofs path 1.
Pathologic cell injury and cell death i mechanism of. Too much stress exceeds the cell s adaptive capacity. Reversible cell injury results in morphological and cellular changes that could be reversed if the stress is taken off. At the cellular level, there are many processes that can lead to necrosis. Virtually all forms of tissue injuries start with molecular or structural alterations in cells. 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. This disorder in phospholipid metabolism is felt to be the critical lesion that. Adaptation change in cell morphology and function in response to a stimulus. If the adaptive capability is exceeded or if the external stress is inherently harmful, cell injury develops fig. Necrosis refers to the spectrum of morphological changes that follow cell death, i.
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. Fatty change occurs in hypoxic injury and various forms of toxic or metaplastic injury manifested by appearance of large or small lipid vacuole in the cytoplasm occur in cells involved and dependant on fat metabolism such as hepatocytes and myocardial cells injured cells may show increased esinophilic staining which becomes. General pathology overview of cell injury and cell death. Reversible cell injury initially, injury is manifested as functional and morphologic changes that are reversible if the damaging stimulus is removed. 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. Normal cells have a fairly narrow range of function or steady state. The hallmarks of reversible injury are reduced oxidative phosphorylation, adenosine triphosphate atp depletion, and cellular swelling caused by changes in ion concentrations and water influx.
The first topic, reversible cell injury, covers the physiology and pathology of reversible cell injuries, and what happens to a cell when a cell is unable to adapt to the stresses of the environment. Sep 21, 2017 reversible cell injury results in morphological and cellular changes that could be reversed if the stress is taken off. Cell injury, adaptation, and necrosis apoptosis and. Adaptation, reversible injury, and cell deathcan be considered. Cell death apply knowledge of biochemistry and cellular physiology to differentiate between pathogenic and physiologic mechanisms of cell death, the resulting morphologic appearance and the physiologic and. 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. Cause of cell injury range from gross mechanical external causes to mild endogenous causes as genetic lack of enzymes etc. This presentation helps you in understanding the basic concepts of cell injury. Cellular swelling appears whenever cells are incapable of maintaining ionic and fluid homeostasis and is the result of loss of function of plasma membrane energydependent ion pumps.
Reversible cell injury with histological slide in english. Ex, skeletal muscle can with stand for half an hour with. The molecular mechanisms connecting most forms of cell injury to ultimate cell death have proved elusive, for several reasons. Glomerular endothelial cell injury and cross talk in. Reversible cell definition is an electrical cell the chemical action in which can be reversed by passing through it a current opposite in direction to that generated by the cell. Fatty change occurs in hypoxic injury and various forms of. Reversible cell injury occurs when the damaged cell is capable of returning to its normal physiological state when the stress is removed from the cell. 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. This chapter will present an overview of how the pathologist views mechanisms of irreversible cell injury cell death, reversible cell injury, and the organisms. Cell injury is reversible up to a certain point, but if the stimulus. Pathology ischemic changeseg, of the myocardium, that can be reversed with timely return of normal circulation to the tissue of interest. The hallmarks of reversible injury are reduced oxidative phosphorylation with resultant depletion of energy stores atp, and cellular swelling caused by. When cells are injured, one of two patterns will generally result. Cell injury is reversible only up to certain point.
Cell injury, cell death, and adaptations new age medical. Bhanu prakash usmle, fmge and neet pg 31,495 views 5. When the doctor looks at the affected cells under a microscope, they have preserved their cellular architecture but the proteins. Difference between reversible and irreversible cell injury.
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