Concentric hypertrophy of left ventricle is seen in-

Ans. is 'b' i.e., Hypertension o Concentric hypertrophy - In pressure overload, e.g. hypertension and aortic stenosis.o Eccentric hypertrophy - In volume overload, e.g. in aortic regurgitation.Adaptations in hearto The cardiac myocyte is terminally differentiated cell that is not able to divide,o Myocardium cannot undergo hyperplasia, i.e. increase in the number of myocyte,o So, myocardium can adapt by increasing the size (i.e. hypertrophy) of the myocyte in response to stress,o There are two types of stresses to heart1. Pressure overloado Occur in hypertension or aortic stenosis.o Pressure overloaded ventricles develop concentric hypertrophy of the left ventricle, with increased in wall thickness Heart size may increase.o The increase in wall thickness may reduce the cavity diameter --> ratio of cavity size to wall thickness decreases,o There is increase in the transverse diameter (width) of myocytes, but cell length remains the same.2. Volume overloado As occurs in aortic regurgitationo There is dilatation of ventricular chamber along with increased thickness of ventricular wall Eccentric hypertrophy.o There is increase both in the transverse diameter (width) and the length of myocytes.o It is due to deposition of the sarcomeres (functional intracellular contractile unit of cardiac muscles) in parallel to the long axis of cells.