Course-Unit- 5 - HPCT 311 - PDF

BACHELOR OF SCIENCE IN MEDICAL LABORATORY SCIENCE: HISTOPATHOLOGIC & CYTOLOGIC TECHNIQUE COURSE MODULE COURSE UNIT WEEK 1 5 5 Etiology of Diseases ✓ Read course and...

BACHELOR OF SCIENCE IN MEDICAL LABORATORY SCIENCE: HISTOPATHOLOGIC & CYTOLOGIC TECHNIQUE COURSE MODULE COURSE UNIT WEEK 1 5 5 Etiology of Diseases ✓ Read course and unit objectives ✓ Read study guide prior to class attendance ✓ Read required learning resources; refer to unit terminologies ✓ Participate in weekly discussion board (Canvas) ✓ Answer and submit course unit tasks At the end of this unit, the students are expected to: 1. Differentiate diseases according to etiology 2. Examine the distinctive features of the commonly encountered diseases 3. Analyze the laboratory findings with the etiology of disease  4. Explain pathognomonic findings in each disease. 5. Explain the pathologic events that take place during the disease process. Robbins Basic Pathology 9th Edition, Chapter 3, 4, 5, 6, 7, 8 Etiology is the cause of a disease or the science that deals with such causes. The word etiology comes from the Greek etio-, which means 'causation' and -ology, which refers to the scientific study of something. A disease's etiology, or cause, generally falls into three main categories; intrinsic, extrinsic and idiopathic. Intrinsic means coming from within. Therefore, any pathological, or disease-causing, change that has occurred from inside the body has occurred as a result of intrinsic factors. The following are examples of intrinsic factors: HDNP Inherited conditions, or conditions that are passed down to you from your parents. An example of this is hemophilia, a disorder that leads to excessive bleeding. Metabolic and endocrine, or hormone, disorders. These are abnormalities in the chemical signaling and interaction in the body. For example, Diabetes mellitus is an endocrine disease that causes high blood sugar. Neoplastic disorders or cancer where the cells of the body grow out of control. Problems with immunity, such as allergies, which are an overreaction of the immune system.. The second category of disease etiology is extrinsic etiologies. This means the cause of the disease, or pathological change, came from outside of the body. The following are examples of extrinsic factors: Infectious agents like bacteria, viruses, fungi, and parasites Animal bites or stings Chemicals, electricity, and radiation  Iatrogenic causes: This is just a fancy way of saying that the problem resulted from a medical professional's actions or within a medical setting. The third and final category of disease etiology is idiopathic, or of unknown cause. Examples of Disease Etiology Genetic disease A disease caused by an abnormality in an individual's genome Disease caused by the absence of a gene or by products of a defective gene Either passed down from patient’s gene or caused by new mutations or changes to the DNA. NATURE OF GENETIC ABNORMALITIES CONTRIBUTING TO HUMAN DISEASE Genetic abnormalities affects the structure and function of proteins disrupts cellular homeostasis and contributes to disease May be caused by: Mutations in Protein-Coding Genes “Mutation” – refers to permanent changes in the DNA. Those that affect germ cells are transmitted to the progeny and may give rise to inherited diseases. Mutations in somatic cells are not transmitted to the progeny but are important in the causation of cancers and some congenital malformations. Alterations in Protein-Coding Genes Structural variations copy number changes (amplifications or deletions), Translocations resulting in aberrant gain or loss of protein function Structural changes may occur in the germline, or be acquired in somatic tissues Three major categories of genetic disorders First category - referred to as Mendelian Disorders - includes many uncommon conditions, such as the storage diseases and inborn errors of metabolism, all resulting from single-gene mutations of large effect. - Most of these conditions are hereditary and familial. Second category - most common disorders of humans - hypertension and diabetes mellitus. - “Multifactorial inheritance” - genetic and environmental influences condition the expression of a phenotypic characteristic or disease. Third category - disorders that are the consequence of numeric or structural abnormalities in the chromosomes. Hemodynamic Disorders Is a disorder in relation with blood flow circulation Changes in intravascular volume, pressure, or protein content, or alterations in endothelial function can be the cause The functions are not regulating property. The factors and chemicals being transported are altered TYPES OF HEMODYNAMIC DISORDERS Hypermia and congestion Edema HETHEH Hemorrhage Hemostasis Thrombosis Embolism HYPEREMIA AND CONGESTION Both hyperemia and congestion are the result of excessive blood in a part of the body. They differ from hemorrhage in that with hyperemia and congestion, the blood is still confined within the vasculature. In hemorrhage, the blood has escaped from the blood vessels.  HYPEREMIA is an excess of blood contained within blood vessels in a part of the body due to an active process. CONGESTION is an excess of blood contained within blood vessels in a part of the body due to a passive process. ACTIVE HYPEREMIA Active process happens when there’s an increase in the blood supply to an organ. This is usually in response to a greater demand for blood. CAUSES OF ACTIVE HYPEREMIA DHIMER Exercise. Your heart and muscles need more oxygen when you’re active. Blood rushes to these organs to supply extra oxygen. Your muscles need up to 20 times their normal supply of blood during a workout. Heat. When you’re running a high fever or it’s hot outside, extra blood flows to your skin to help your body release heat. Digestion. After you eat, your stomach and intestines need more blood to help them break down foods and absorb nutrients. Inflammation. During an injury or infection, blood flow to the site increases. Menopause. Women who are in menopause often have hot flashes, which causes a rush of blood to the skin — especially of the face, neck, and chest. Blushing is a similar response. Release of a blockage. Hyperemia can happen following ischemia, which is poor blood flow to an organ. Once ischemia is treated, blood rushes to the area. PASSIVE HYPEREMIA (CONGESTION) Passive process is when blood can’t properly exit an organ, so it builds up in the blood vessels. This type of hyperemia is also known as congestion. CAUSES OF PASSIVE HYPEREMIA (CONGESTION) Heart failure or ventricular failure. The left and right ventricles are the two main pumping chambers of the heart. The right ventricle pumps blood to the lungs, and the left ventricle pumps oxygen-rich blood to the body. When the heart can’t beat well enough to push blood through the body, blood begins to back up. This backup causes swelling, or congestion, in organs like the liver, lungs, spleen, and kidneys.  Deep vein thrombosis (DVT). DVT is caused by a clot in one of the deep veins — often in your lower legs. The clot can break free and get lodged in a vein in your lung, called a pulmonary embolism. Hepatic vein thrombosis (HVT), also called Budd-Chiari syndrome. HVT is a blockage in the veins of the liver caused by a blood clot. EDEMA Edema is an abnormal accumulation of fluid in the interstitium, located beneath the skin and in the cavities of the body, which can cause severe pain. Clinically, edema manifests as swelling. The amount of interstitial fluid is determined by the balance of fluid homeostasis and the increased secretion of fluid into the interstitium. IIHP FOUR MAJOR CAUSES OF EDEMA 1. Increased intravascular hydrostatic pressure causes edema. Venous obstruction results in increased hydrostatic pressure as blood backs up in the venous system, with leakage of crystalloids and fluid into the interstitial tissues. 2. Decreased Intravascular Osmotic Pressure (hypoproteinemia). Reduction in serum albumin decreases intravascular oncotic pressure and causes edema. 3. Increased Vascular Permeability. Injury to vascular walls allows leakage of fluid, protein, and cells, and causes edema. 4. Lymphatic Obstruction (lymphangiectasia). Blockage of lymph vessels causes edema. GENERALIZED VS. LOCOLIZED EDEMA Edema is usually localized to one area. Infrequently it affects most or all of the body. This is referred to as “generalized edema”. Anasarca is a term that means general edema but in common usage, this term is only used for fetuses. Types of edema as either a transudate or an exudate. TRANSUDATE accumulation of fluid due to a hydrostatic imbalance between the intravascular and extravascular compartments despite normal vascular permeability, characterized by clear fluid, low specific gravity, and low protein. EXUDATE accumulation of fluid due to increased vascular permeability characterized by turbid fluid, high specific gravity, high protein concentrations, and high cell counts. HEMORRHAGE An escape of blood from a ruptured blood vessel, especially when profuse. defined as the extravasation of blood from vessels The risk of hemorrhage is increased in a wide variety of clinical disorders collectively called hemorrhagic diatheses. Hemorrhage may be manifested by different appearances and clinical consequences Hematoma- a solid swelling of clotted blood within the tissues. Petechiae - are minute (1 to 2 mm in diameter) hemorrhages into skin, mucous membranes, or serosal surfaces. Purpura - are slightly larger (3 to 5 mm) hemorrhages; can result from trauma, vasculitis, and increased vascular fragility. Ecchymoses - are larger (1 to 2 cm) subcutaneous hematomas (colloquially called bruises). Classifications of Hemorrhage depends on: Nature of the vessel involved Timing of the hemorrhage Duration of the hemorrhage Nature of the bleeding Type of intervention The clinical significance of any particular hemorrhage depends on: volume of blood lost the rate of bleeding THROMBOSIS  is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. Thrombi on heart valves are called vegetations. Three primary abnormalities that lead to thrombus formation (called Virchow’s triad): (1) Endothelial injury, (2) stasis or turbulent blood flow, and (3) hypercoagulability of the blood Endothelial injury an important cause of thrombosis, particularly in the heart and the arteries, where high flow rates might otherwise impede clotting by preventing platelet adhesion or diluting coagulation factors. (e.g., by toxins, hypertension, inflammation,or metabolic products) Abnormal Blood Flow Turbulence contributes to arterial and cardiac thrombosis by causing endothelial injury or dysfunction, as well as by forming countercurrents and local pockets of stasis. (e.g., due toaneurysms, atherosclerotic plaque) Hypercoagulability It is loosely defined as any alteration of the coagulation pathways that predisposes affected persons to thrombosis, and can be divided into: A. Primary (inherited) hypercoagulability most often is causedby mutations in the factor V and prothrombin genes. B. Secondary (acquired) hypercoagulability is seen in: Prolonged bed rest or immobilization Myocardial infarction Atrial fibrillation Tissue injury (surgery, fracture, burn) Cancer Prosthetic cardiac valves Disseminated intravascular coagulation Heparin-induced thrombocytopenia Antiphospholipid antibody syndrome EMBOLISM An embolism is a detach intravascular solid, liquid or gaseous mass that is carried by the blood to site of distant from point of origin. Pulmonary embolism SPAAF Systemic thromboembolism Fat embolism Amniotic fluid embolism Air Embolism INFARCT An infarct is an area of ischemic necrosis cause by occlusion of vascular supply to affected tissue. The process by which lesion formed term infarction. CLASSIFICSTION OF INFARCT 1. Red infarcts 2. White infarcts 3. Septic infarcts Factors that influence infarct development Anatomy of vascular supply 2. Rate of occlusion 3. Tissue vulnerability to ischemia 4. Hypoxemia Nutritional Diseases Malnutrition Primary Malnutrition – One or all of the components are missing in the diet Secondary Malnutrition – Results from nutrient malabsorption, impaired storage, excess losses, or increased requirements PROTEIN-ENERGY MALNUTRITION PEM – range of clinical syndromes, all resulting from a dietary intake of protein and calories that is inadequate to meet the body’s needs. Marasmus Growth retardation and loss of muscle mass as a result of catabolism and depletion of somatic protein compartment MICE Subcutaneous fat is also mobilized and used as fuel ✓ Extremities are abnormally thin and weak ✓ Multivitamin deficiency ✓ Immune deficiency ✓ Concurrent infections Kwashiorkor Protein deprivation is greater than the reduction in total calories Sever loss of visceral protein compartment ✓ Increased fluid retention (edema)  ✓ Skin lesions with hyperpigmentation, desquamation, and hypopigmentation ✓ Bands of pale and dark colored hair ✓ Enlarged fatty liver Secondary Protein-Energy Malnutrition Common in chronically ill or hospitalized patients Cachexia – severe form of secondary PEM PIF Proteolysis-inducing factor – directly stimulates the degradation of skeletal muscle proteins Tumor-necrosis factor – stimulates fat mobilization from lipid stores II. ANOREXIA NERVOSA AND BULIMIA Anorexia Nervosa Self-induced starvation resulting in marked weight loss ✓ Amenorrhea resulting from decreased GRH ✓ Dehydration and electrolyte imbalance ✓ Decreased bone density ✓ Major complication: cardiac arrhythmia and sudden death Bulimia The patient binges on food and then induces vomiting ✓ Electrolyte imbalances ✓ Pulmonary aspiration of gastric contents ✓ Esophageal and stomach rupture III. VITAMIN DEFICIENCY Vitamin A Deficiency ✓ Depleted stores of Vitamin A due to infection in children ✓ Poor absorption in newborns ✓ In adults, malabsorption syndromes may develop (celiac disease, Crohn disease, and colitis) ✓ Toxicity occurs from overuse of supplements and high vitamin A in foods such as liver Manifestations: 1. Impaired vision (night blindness) 2. Xerophthalmia (dry eye) Vitamin D Deficiency Rickets – children Osteomalacia – adults Causes: ✓ Limited exposure to sunlight ✓ Heavily veiled women ✓ Children born to mothers who have frequent pregnancies followed by lactation ✓ Inhabitants of northern climates with scant sunlight ✓ Renal disorders ✓ Malabsorption disorders  Toxicity: Hypervitaminosis – megadoses of orally administered vitamin D – Children: metastatic calcifications of soft tissues (kidney) – Adults: bone pain and hypercalcemia Vitamin C Deficiency Scurvy Bone disease in growing children Hemorrhages and healing defects in children and adults Appears in patients undergoing peritoneal dialysis and hemodialysis and among food faddists Excess: Excreted in urine but may cause uricosuria and increased absorption of iron (iron overload) IV. OBESITY A state of increased body weight, due to adipose tissue accumulation which produce adverse health effects Disorder of energy balance METABOLIC DISEASES  A metabolic disorder can happen when abnormal chemical reactions in the body alter the normal metabolic process.  It can also be defined as inherited single gene anomaly, most of which are autosomal recessive Neoplasia New growth - “ An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persist in the same excessive manner after cessation of the stimuli that evoked the change.” General Pathogenesis of Tumors Initiation -the primary and essential step in the process. -a carcinogen induces non-lethal mutation(s) in a cell. -point at which an irreversible alteration, usually genetic, is introduced to a target cell. Promotion - The process whereby an initiated tissue or organ develop focal proliferations and it requires the presence of continuous stimulation -transformed cell under the effect of PROMOTERS, begins to multiply, giving the beginning to the clone of daughter cells. - The primary tumor tissue appears, which consists of similar cells. - Progression - continual accumulation of multiple mutations results in an invasive phenotype and distant metastasis. Classification of Neoplasia Benign tumor Fibroma – benign tumor arising in fibrous tissue Chondroma – benign cartilaginous tumor Classified by: basis of their microscopic pattern basis of their macroscopic pattern Malignant Tumor Arising in “solid” mesenchymal tissues or its derivatives are called sarcomas Commonly called Cancer; They invade and destroy the surrounding tissue and may form metastases, and if left untreated or unresponsive to treatment, will prove fatal. Metaplasia – Abnormal change in nature Dysplasia – The presence of cells of an abnormal type within a tissue , which may signify a stage preceeding the development of cancer. ETIOLOGY/CAUSES OF CANCER: CARCINOGENIC AGENTS Three classes of carcinogenic agents: 1. Chemicals 2. Radiant Energy 3. Microbial products INFECTIOUS DISEASES  Is the steps or mechanisms involved in the development of disease.  Disease caused by infection include 20 – 40 % of the total number of human diseases known to science. To date, more than 1,200 of infectious disease are recognized and their number increases regularly.  Infectious disease remain an important health problem worldwide despite the availability and use of effective vaccines and antibiotics. In the United States, 2 of the top 10 leading causes of death are attributed to infection (pneumonia and septicemia). Classification FBPV PARASITIC INFECTION FUNGAL INFECTION BACTERIAL INFECTION VIRAL INFECTION STEPS IN THE PATHOGENESIS OF INFECTIOUS DISEASES ENTRY ATTACHMENT MULTIPLICATION INVASION/ SPREAD OF THE PATHOGEN EVASION OF HOST DEFENSE DAMAGE TO HOST ENVIRONMENTAL DISEASE  The term environmental disease refers to the lesions and disease caused by exposure to chemical or physical agents in the ambient, workplace, and personal environments, including disease of nutritional origins.  Environmental diseases are the major cause of disability and suffering and constitute a heavy financial burden, particularly in developing countries. MECHANISMS OF TOXICITY  Human exposure to the pollutants. Pollutants contained in air, water, and soil are absorbed through the lungs, GI tract, and skin. In the body they may act at the site of absorption but generally transported through the bloodstream to various organs, where they may be stored or metabolized.  Metabolism of xenobiotics may result in the formation of water-soluble compounds that are excreted or in activation of the reagent, creating a toxic metabolite. EXOGENOUS CHEMICALS  Known as xenobiotics are absorbed by the body through inhalation, ingestion, and skin contact, and can either be eliminated from the body or accumulated in the fat, bone, brain, and other tissues.  Xenobiotics can be converted into non-toxic products, or be activated to generate toxic compounds, through a two-phase reaction process that involves the cytochrome P-450 system. ENVIRONMENTAL POLLUTION  Airborne microorganisms have long been major causes of morbidity and mortality.  More widespread are the chemical and particulate pollutants found in the air, especially in industrialized nations. OUTDOOR AIR POLLUTION  The ambient air in industrialized nations is contaminated with an unsavory mixture of gaseous and particulate pollutants.  In the USA, the Environmental Protection Agency (EPA) monitors and sets allowable upper limits for six pollutants : Sulfur dioxide, Carbon monoxide, Ozone, Nitrogen dioxide, Lead, and particulate matter. Edema is an abnormal accumulation of fluid in the interstitium, located beneath the skin and in the cavities of the body, which can cause severe pain. Clinically, edema manifests as swelling. Embolism is detach intravascular solid, liquid or gaseous mass that is carried by the blood to site of distant from point of origin. Etiology is the cause of a disease or the science that deals with such causes. Exudate accumulation of fluid due to increased vascular permeability characterized by turbid fluid, high specific gravity, high protein concentrations, and high cell counts. Genetic disease - is disease caused by the absence of a gene or by products of a defective gene. Hemodynamic Disorders - a disorder in relation with blood flow circulation Hemorrhage - defined as the extravasation of blood from vessels Infarct is an area of ischemic necrosis cause by occlusion of vascular supply to affected tissue. The process by which lesion formed term infarction. Thrombosis - is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. Vinay, Mescher (2010), Robbins and Cotran pathologic basics of Disease, 9th Ed. Read and study Chapter 3, 4, 5, 6, 7, Basic Pathology by Robbins 9th edition Create a table that will identify the three categories of disease etiology and give examples in each categories.. Story, Lachel, (2012), Pathophysiology: A practical approach Damjanov, Ivan. (2012), Pathology for the Health professions, 4th edition. Young, Barbara (2012), Wheater’s Basic Pathology: A Text Atlas and Review of Histopathology. Vinay, Mescher (2010), Robbins and Cotran pathologic basics of Disease, 8th Ed.