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Showing posts from April, 2020

Cell Adaptation

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Adaptive Disorders Definition :- Cell become change or adapt in response to adverse environmental changes that's called adaptation. Types of adaptation 1. Atrophy (decrease cell size) 2. Dysplasia ( abnormal growth or development of cell ) 3. Hyperplasia ( increase reproduction rate of the cell ) 4. Hypertrophy ( increase cell size ) 5. Metaplasia ( conversion of the cell from one type to another type e.g. squamus cell convert into columnar cell ) Adaptive Disorders Difference between Metaplasia and Dysplasia Similar Posts - Cell Injury Haemorrhage Infarction Necrosis Emphysema Food Poisoning Diabetes Mellitus Endocarditis

Dysplasia / Atypical hyperplasia

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Definition –  It is the disordered cellular development associated with metaplasia and hyperplasia caused by chronic irritation and prolonged inflammation. It is occur most commonly in epithelial cells. Dysplasia characterised by cellular proliferation and cytologic changes as under… Increase number of layers of epithelial cells. Disorderly arrangement of cells from basal layer to the surface layer. Loss of polarity i.e. nuclei lying away from basement membrane. Cellular and nuclear pleomorphism. Increase nucleocytoplasmic ratio. Nuclear hyperchromatism. Increase mitotic activity. Most common examples of dysplastic changes are the uterine cervix and respiratory tract. Difference between Metaplasia and Dysplasia Similar Posts - Atrophy Hyperplasia Hypertrophy Metaplasia

Metaplasia

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Definition – Metaplasia is a reversible condition in which one type of epithelial or mesenchymal adult cells convert into another type of epithelial or mesenchymal cells, usually in response to abnormal stimuli and it reverts back after removal of stimulus. If stimulus persists for long time then metaplasia convert into dysplasia and further convert into cancer. Types – (1) Epithelial metaplasia (2) Mesenchymal metaplasia 1. Epithelial metaplasia – This is the more common type in which metaplastic changes may be patchy or diffuse and usually replaced by stronger but less well-specialised epithelium. There are two types of epithelial metaplasia… A. SQUAMOUS METAPLASIA – It is caused by chronic irritation that may be mechanical, chemical or infective in origin. Some common examples… In bronchus (normally lined by pseudostratified columnar ciliated epithelium) in chronic smokers. In uterine endocervix (normally lined by simple columnar epithelium) in prolapsed of the uter

Hyperplasia

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Definition – Hyperplasia is an increase in the number of parenchymal cells resulting in enlargement of the organ or tissue. Quite often, both hyperplasia and hypertrophy occur together. Causes – It may be physiological or pathological… PHYSIOLOGICAL HYPERPLASIA –                   1. Hormonal hyperplasia, it occurs due hormonal stimulation. a.        Hyperplasia of female breast at puberty, during pregnancy and lactation. b.       Hyperplasia of pregnant uterus. c.        Proliferative activity of normal endometrium after a normal menstrual cycle. d.       Prostatic hyperplasia in old age. 2. Compensatory hyperplasia i.e. it occurs due to removal of part of an organ or in the contralateral organ in paired organ e.g. a.        Regeneration of liver after partial hepatectomy. b.       Regeneration of epidermis after skin abrasion. c.        Hyperplasia of nephrons after another nephrectomy. PATHOLOGICAL HYPERPLASIA – It is occurs due to excessive stimulation

Hypertrophy

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Hypertrophy Definition – Hypertrophy is an increase in the size of parenchymal cells resulting in enlargement of the organ or tissue, without any change in the number of cells. Causes – It may be physiological or pathological… PHYSIOLOGICAL HYPERTROPHY – Enlarged size of uterus in pregnancy. PATHOLOGICAL HYPERTROPHY – Hypertrophy of cardiac muscles, e.g. systemic hypertension, aortic valve disease (stenosis and insufficiency), mitral insufficiency. Hypertrophy of smooth muscles, e.g. cardiac achalasia (in oesophagus), pyloric stenosis (in stomach), intestinal strictures, muscular arteries in hypertension. Hypertrophy of skeletal muscles, e.g. athletes and manual labourers. Compensatory hypertrophy after removal of contralateral organ, e.g. nephrectomy, adrenal hyperplasia. Cardiac Hypertrophy MORPHOLOGICAL FEATURES – The affected organ is enlarged and heavy. There is enlargement of muscles fibres as well as of nuclei. At ultra-structural level, there is in

Infarction

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Infarction Definition – A necrotic area is called infarct and the process of infarct formation is called infarction. Causes – Ischaemic necrosis (most common), stagnant hypoxia (venous obstruction), thrombosis, embolism, narrowing of the coronary artery (atherosclerosis) etc. Types of infarcts – 1. According to colour …             a. Pale or anemic infarct – It is due to arterial occlusion, commonly seen in compact organ like heart, kidney and spleen.             b. Red or haemorrhagic infarct – It is due to obstruction of the artery, commonly seen in soft loose tissue e.g. lungs and intestine. Haemorrhagic Infarct of the Lung 2. According to the age … Recent and old. 3. According to the presence or absence of the infection…             a. Bland – Free from bacterial contamination             b. Infected – Infected with bacterial contamination. 4. According to the type of action…             a. Bacteriostatic – It inhibit growth of bacteria e.g. tetr

Haemorrhage

Haemorrhage Definition – Haemorrhage is the escape of blood from a blood vessel. HAEMATOMA – Extravasation of blood into the tissue with resultant swelling is known as haematoma. ECCHYMOSIS – Large extravasations of blood into the skin and mucous membranes are called ecchymosis. PURPURA – Small areas of haemorrhage (up to 1 cm) into the skin and mucous membrane called purpura. PETECHIAE – Minute pinhead size haemorrhages on the skin are called petechiae. FORMS – Epistaxis   (nosebleed) Haemoptysis (coughing up blood) Haematemesis (vomiting blood) Haematuria (blood in urine) Melena (dark stool) Polymenorrhea (short menstrual cycle <21 days) Menorrhagia (heavy periods) Postpartum haemorrhage (excessive bleeding after childbirth) Antepartum haemorrhage (genital bleeding during pregnancy, third trimester to till birth or delivery) Classification – 1. According to the nature or type … (a) External or visible haemorrhage (b) Internal or concealed haemorrha

GHAI Essential Pediatrics

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GHAI Essential Pediatrics (Eighth edition) GHAI Essential Pediatrics Book 8th edition CONTENTS 1. Introduction to Pediatrics 2. Normal Growth and its Disorders – Somatic growth, physical growth, growth disorders, abnormalities of head size and shape. Cunningham’s Mannual of practical anatomy vol-3 ( 16 th edition ) 2. Development – Normal development, behavioral disorders, habit disorders and tics. 4. Adolescent Health and Development – Physical aspect, cognitive and social development, problems faced by adolescents, role of health care provider. 5. Fluid and Electrolyte Disturbances – Composition of body fluids, deficit therapy, sodium, potassium, calcium, magnesium, acid-base disorders.   Rapid Review Biochemistry by John W. Pelley and Edward F. Goljan 6. Nutrition – Macronutrients, normal diet, undernutrition, management of malnutrition. 7. Micronutrients in Health and Disease – Fat and water soluble vitamins, mine