Cell Injury Part 1 Lecture Notes PDF

Cell injury 1 By: Pro.Dr.Gehan Nabil Alagmy PHD: Histopathology Email:[email protected] Learning objectives  Learning objectives Understand what is cell injury Descrie etiology , Type & mechanism. of cell injury Define cellular response to injury Description of cellula...

Cell injury 1 By: Pro.Dr.Gehan Nabil Alagmy PHD: Histopathology Email:[email protected] Learning objectives  Learning objectives Understand what is cell injury Descrie etiology , Type & mechanism. of cell injury Define cellular response to injury Description of cellular adaptation definition,types & examples Cell injury Cell injury definition a variety of stresses a cell encounters as a result of changes in its internal and external environment. Cell Stresses response Normal cell Cell injury definition Virchow's Cellular theory of disease (1859): diseases occur due to abnormalities at the level of cells The cellular response to stress may vary and depends upon the following: 1- The type of cell involved. 2-Extent and type of cell injury Etiology of cell injury  Etiology of cell injury Single Genetic disorders Multiple Idiopathic Physical Chemical Acquired Hypoxia disorders Microbial Aging Nutritional Cellular Response  Cellular response Cellular Reversible cell Irreversible cell injury adaptation injury Intracellular edema Hyperplasia Fatty change Hypertrophy Necrosis- Hyaline change Atrophy gangrenous Amyloidosis Metaplasia Apoptosis Mucoid degeneration Dysplasia Pathological pigment  Cellular response Physiological Cellular hormones (breast Cellular adaptation adaptation hyperplasia in lactation) Or Pathological - Hyperplasia Hypertrophy Definition Atrophy reversible changes in the size, Metaplasia number, metabolic activity, or Dysplasia functions of cells in response to changes in their environment  Cellular Adaptation-Hyperplasia Hyperplasia (Définition) An increase in the Cellular number of cells in adaptation an organ or tissue, which may then Hyperplasia have increased volume. Hypertrophy Atrophy Metaplasia Dysplasia  Hormonal Hyperplasia: influence of hormonal stimulation.pregnant uterus or normal endometrium after a normal menstrual cycle. (Endometrial hyperplasia) Compensatory Hyperplasia: 1. Regeneration of the liver after partial hepatectomy. 2. Skin warts from hyperplasia of the epidermis due to human papilloma virus  Cellular Adaptions-HypertrophY Definition An increase in the size of cells, Cellular and an increase in the size of the adaptation organ. Physiologic: Hyperplasia physiologic growth of the uterus during pregnancy. Hypertrophy Types Atrophy Pathologic: Metaplasia hypertrophy of heart is the most common due to chronic hemodynamic Dysplasia overload. Cellular Adaptions-HypertrophY  Cellular Adaptation-Atrophy Acquired loss of size due to Définition reduction of cell size or number Cellular of parenchyma cells in an organ adaptation Physiologic due to loss of endocrine Hyperplasia Stimulation. Types - Atrophy of lymphoid tissue, appendix, Hypertrophy and thymus. - Atrophy of gonads after menopause. Atrophy Metaplasia Pathologic: Starvation atrophy. Dysplasia Ischaemic Diseases  Cellular Adaptation-Metaplasia Definition: Metaplasia is a reversible change in which one adult cell type is replaced by another Cellular adult cell type. adaptation Causes Changes in environment or inflammation Nutritional Hyperplasia Types Hypertrophy EPITHELIAL METAPLASIA Squamous metaplasia: changes in bronchus, uterine, Atrophy endocervix, gallbladder Metaplasia Columnar metaplasia: Intestinal metaplasia in healed chronic gastric ulcer and Barrett’s esophagus Dysplasia MESENCHYMAL METAPLASIA - Osseous metaplasia. Cartilaginous metaplasia.  Cellular Adaptation-Dysplasia Definition :disordered cellular development. Cellular also referred to as atypical hyperplasia adaptation Epithelial dysplasia is characterized by cellular proliferation Hyperplasia cytologic changes Hypertrophy - Increased number of layers of epithelial cells - Disorderly arrangement of cells from the basal Atrophy layer to the surface layer - Loss of basal polarity i.e. nuclei lying away Metaplasia from the basement membrane - Nuclear hyperchromatism& Increased mitotic Dysplasia activity. Conditions associated with skeletal dysplasia include Cervical spine instability. Spinal stenosis. Leg bowing or knock knees. Stiff joints and premature arthritis. Clubfoot.. Exercises 1. Compare & contrast the various types of cellular adaptation