The human heart is made up of three layers of tissue that are surrounded by the pericardium, a membrane that protects and confines the heart. The outermost layer, closest to the pericardium, is the epicardium. The pericardial cavity separates the pericardium from the epicardium. Beneath the epicardium is the myocardium, the middle layer, and the endocardium, the innermost layer. There are four chambers of the heart: the right atrium, the right ventricle, the left atrium, and the left ventricle.

Bradycardia is a medical condition in which the heart rate is slower than normal. It occurs when the heart's natural pacemaker, the sinus node, generates slower electrical impulses than the standard rhythm. In adults, bradycardia is diagnosed when the pulse rate falls below 60 beats per minute, indicating a deviation from the normal heart rate range.
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with bradycardia...

The heart, a muscular organ located in the chest, functions as the body's pump, circulating blood through the vascular system. It has four chambers: two atria on top and two ventricles below. The right atrium receives deoxygenated blood from the body and passes it to the right ventricle, which pumps it to the lungs for oxygenation. The left atrium receives oxygenated blood from the lungs and transfers it to the left ventricle, which pumps it to the rest of the body.
The heart's structure...

The heart wall comprises three distinct layers: the epicardium, myocardium, and endocardium. The outermost layer, the epicardium, is the visceral layer of the serous pericardium, featuring a thin, transparent mesothelial surface and an inner layer of areolar connective tissue with fat deposits that increase with age.
The myocardium, the thickest layer, consists of cardiac muscle cells interconnected by intercalated discs and crisscrossing connective tissue fibers. These muscle fibers contract...

The human heart is a complex organ with an intricate system of valves that regulate blood flow. There are two main types of valves: atrioventricular (AV) valves and semilunar valves.
The AV valves prevent the backflow of blood from the ventricles to the atria during ventricular contraction. These valves function with the assistance of the chordae tendineae and papillary muscles. When the ventricles are relaxed, the chordae tendineae are slack, allowing blood to flow from the atria into the...

The heart is a hollow, muscular organ approximately the size of a fist, consisting of four chambers. It is enclosed in the pericardium, a fibrous sac with two layers: the visceral and parietal pericardium, separated by a fluid-filled space containing serous fluid to reduce friction.
The heart has three layers: the innermost endocardium, the muscular myocardium, and the outer epicardium, all working together for optimal cardiac function.
Chambers of the Heart
The heart is made up of four...