Myocarditis is caused by infectious (coxsackie A and B viruses, Chagas disease) andimmune causes. Clinically, the patient may be asymptomatic or may suffer from acute heart failure or even dilated cardiomyopathy.
Definitions The study of the essential nature of disease, including symptoms/signs, patho-genesis, complications, and morphologic consequences including structural and functional alterations in cells, tissues, and organs The study of all aspects of the disease process focusing on the pathogenesis leading to classical structural changes (gross and histopathology) and molecu-lar alterations The etiology (cause) of a disease may be genetic or environmental. The pathogen-esis of a disease defines the temporal sequence and the patterns of cellular injurythat lead to disease. Morphologic changes of the disease process include both gross changes and microscopic changes. The clinical significance of a disease relates to its signs and symptoms, disease course including complications, and prognosis. Methods Used Gross examination of organs on exam questions has 2 major components: identify-ing the organ and identifying the...
CARCINOGENESIS Carcinogenesis is a multistep process, and development of all human cancersappears to require the accumulation of multiple genetic changes. These changes can involve either inherited germline mutations or acquired mutations. Once a sin-gle severely mutated cell forms, monoclonal expansion of the cell’s line can cause a tumor. Most important mutations in tumorogenesis involve growth promoting genes (proto-oncogenes), growth inhibiting tumor suppressor genes, or the genes regulating apoptosis and senescence. Activation of growth promoting oncogenes. Proto-oncogenes are normal cellulargenes involved with growth and cellular differentiation. Oncogenes are derived from proto-oncogenes by either a change in the gene sequence, resulting in a new gene product (oncoprotein), or a loss of gene regulation resulting in overexpression of the normal gene product. Mechanisms of oncogene activation include point muta-tions, chromosomal translocations, gene amplification, and...
SHOCK Shock is characterized by vascular collapse and widespread hypoperfusion of cells and tissue due to reduced blood volume, cardiac output, or vascular tone. The cel-lular injury is initially reversible; if the hypoxia persists, the cellular injury becomes irreversible, leading to the death of cells and the patient. Major Causes of Shock · Cardiogenic shock (pump failure) can be due to myocardial infarction, car-diac arrhythmias, pulmonary embolism, and cardiac tamponade. · Hypovolemic shock (reduced blood volume) can be due to hemorrhage, fluidloss secondary to severe burns, and severe dehydration. · Septic shock (viral or bacterial infection) causes cytokines to trigger vasodilatation and hy...
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