Does myocardium have thick?
Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle becomes abnormally thick (hypertrophied). The thickened heart muscle can make it harder for the heart to pump blood.
What is myocyte hypertrophy?
Abstract. One of the most controversial problem in cardiac muscle pathology is the existence of myocyte hyperplasia. The term hypertrophy indicates an increase in size of the individual muscle cells without changing their total number, whereas in hyperplasia there occurs proliferation of the myocyte.
What is boxcar nuclei?
Myocyte hypertrophy is best evaluated in correlation with heart size. The classic histologic description is rectangular, hyperchromatic nuclei, often called “box-car” nuclei (Image 1). Myocytes may be obviously enlarged or barely noticeably enlarged, which is why correlation with heart size in crucial.
What is Myofiber disarray?
“Myofiber disarray” defines a nonparallel arrangement of cardiac myocytes. The presence of a sufficient quantity of myocardial fibers showing this change is considered to be a specific histological feature of hypertrophic cardiomyopathy (HCM).
Which myocardium is the thickest?
The myocardium of the left ventricle, which must drive blood out into the systemic circulation, is, therefore, thickest; the myocardium of the right ventricle, which propels blood to the lungs, is moderately thickened, while the atrial walls are relatively thin.
Why is the myocardium thick?
The myocardium is thickest in the left ventricle, as the left ventricle must create a lot of pressure to pump blood into the aorta and throughout systemic circulation. Cardiac muscle has a high density of mitochondria and a large blood supply, which keep it functioning continuously.
What does a myocyte look like?
Muscle cells, commonly known as myocytes, are the cells that make up muscle tissue. Skeletal muscle cells are long, cylindrical, multi-nucleated and striated.
What does a myocyte do?
The muscle myocyte is a cell that has differentiated for the specialized function of contraction. Although cardiac, skeletal, and smooth muscle cells share much common functionality, they do not all share identical features, anatomical structures, or mechanisms of contraction.
What causes boxcar nuclei?
The main pathologic findings are in the heart, which shows an increase in mass caused principally by left ventricular hypertrophy. Histologically, the individual myocytes are enlarged and show nucleomegaly (“box car” nuclei) (see the image below).
What is concentric cardiac hypertrophy?
Concentric left ventricular hypertrophy is an abnormal increase in left ventricular myocardial mass caused by chronically increased workload on the heart, most commonly resulting from pressure overload-induced by arteriolar vasoconstriction as occurs in, chronic hypertension or aortic stenosis.
What causes myocyte disarray?
CONCLUSIONS—Myocyte disarray is probably a direct response to functional or structural abnormalities of the mutated sarcomeric protein, while fibrosis and small vessel disease are secondary phenomena unrelated to disarray, but modified by factors such as left ventricular mass, sex, and perhaps local autocrine factors.
What causes myocardial fibrosis?
Coronary heart disease, aortic stenosis and hypertension are the most frequent causes of myocardial fibrosis (13). Aortic stenosis and hypertension result in pressure overload of the left ventricle where the increased wall stress induces hypertrophy and interstitial fibrosis (2–4).
What is the thickest part of the myocardium?
What is the thickest part of the myocardium? The myocardium is thickest in the left ventricle, as this chamber must create substantial pressure to pump blood into the aorta and throughout systemic circulation. How the thickness of the four chambers of the myocardium vary according to their function?
Why is the myocardium thicker in the ventricles?
Although the structure of myocardium is the same in the atria and ventricles, it is thicker in the ventricles. This is due to the greater hydrostatic pressure that the ventricles must overcome when pumping the blood into the systemic vessels. The endocardium is the innermost layer of the heart.
What is myocardium made up of?
Myocardium(myo-cardium) is the middle layer of the heart wall. It is composed of cardiac muscle fibers, which enable heart contractions. The myocardium is the thickest layer of the heart wall, with its thickness varying in different parts of the heart.
What determines the thickness of the myocardium of the four chambers?
The thickness of the myocardium of the four chambers varies according to function. The atria are thin-walled because they deliver blood into the adjacent ventricles and the ventricles are equipped with thick muscular walls because they pump blood over greater distances.