This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Concentric hypertrophy of heart is associated - \nSelect and explain. \nA. Systemic Hypertension, B. Mitral regurgitaion, C. Hypertrophic cardiomyopathy, D. Mitral stenosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Adaptations in heart\n\nThe cardiac myocyte is a terminally differentiated\xa0cell that is not able to divide,\nMyocardium cannot undergo hyperplasia, i.e. an increase in the number of myocytes,\nSo, myocardium can adapt by increasing the size (i.e. hypertrophy) of the myocyte in response to stress,\nThere are two types of stresses to heart\n\n1. Pressure overload\n\nOccur in hypertension or aortic stenosis.\nPressure overloaded ventricles develop concentric hypertrophy of the left ventricle, with increased in wall thickness → Heart size may increase.\nThe increase in wall thickness may reduce the cavity diameter → ratio\xa0of cavity size to wall\xa0thickness decreases.\nThere is an increase in the transverse diameter (width) of myocytes, but cell length remains the\xa0same.\n\n2. Volume overload\n\n\xa0As occurs in aortic regurgitation\nThere is dilatation\xa0of ventricular chamber along with the increased thickness of ventricular wall →\xa0Eccentric hypertrophy.\nThere is increasing both in the transverse diameter (width) and the length of myocytes. \nIt is\xa0due to deposition\xa0of the sarcomeres (functional\xa0intracellular contractile\xa0unit of cardiac\xa0muscles) in parallel to the long axis of cells.\nConcentric hypertrophy → In pressure overload, e.g. hypertension and aortic\xa0stenosis.\nEccentric hypertrophy → In volume overload, e.g. in aortic\xa0regurgitation.', 'role': 'assistant'}]