Question

Discuss the layers, chambers, valves, vasculature, or the conduction system of the heart

Answer 1

Ans) The wall of the heart consists of three layers: the epicardium (external layer), the myocardium (middle layer) and the endocardium (inner layer). The epicardium is the thin, transparent outer layer of the wall and is composed of delicate connective tissue.

- In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart.

- The heart has 4 valves:
The mitral valve and tricuspid valve, which control blood flow from the atria to the ventricles.
The aortic valve and pulmonary valve, which control blood flow out of the ventricles.

- The conducting system of the heart consists of cardiac muscle cells and conducting fibers (not nervous tissue) that are specialized for initiating impulses and conducting them rapidly through the heart (see the image below). They initiate the normal cardiac cycle and coordinate the contractions of cardiac chambers. Both atria contract together, as do the ventricles, but atrial contraction occurs first. The conducting system provides the heart its automatic rhythmic beat. For the heart to pump efficiently and the systemic and pulmonary circulations to operate in synchrony, the events in the cardiac cycle must be coordinated.