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- The Heart Wall Is Composed of Three Layers. The muscular wall of the heart has three layers. The outermost layer is the epicardium (or visceral pericardium).
- The Atria Are the Heart’s Entryways for Blood. The left atrium and right atrium are the two upper chambers of the heart. The left atrium receives oxygenated blood from the lungs.
- Each Heart Beat Is a Squeeze of Two Chambers Called Ventricles. The ventricles are the two lower chambers of the heart. Blood empties into each ventricle from the atrium above, and then shoots out to where it needs to go.
- The Valves Are Like Doors to the Chambers of the Heart. Four valves regulate and support the flow of blood through and out of the heart. The blood can only flow one way—like a car that must always be kept in drive.
- Pericardium
- Structure of The Heart Wall
- Chambers of The Heart
- Valves of The Heart
- Conduction System of The Heart
The heart sits within a fluid-filled cavity called the pericardial cavity. The walls and lining of the pericardial cavity are a special membrane known as the pericardium. Pericardium is a type of serous membrane that produces serous fluid to lubricate the heart and prevent friction between the ever beating heart and its surrounding organs. Besides ...
The heart wall is made of 3 layers: epicardium, myocardium and endocardium. 1. Epicardium. The epicardium is the outermost layer of the heart wall and is just another name for the visceral layer of the pericardium. Thus, the epicardium is a thin layer of serous membrane that helps to lubricate and protect the outside of the heart. Below the epicard...
The heart contains 4 chambers: the right atrium, left atrium, right ventricle, and left ventricle. The atria are smaller than the ventricles and have thinner, less muscular walls than the ventricles. The atria act as receiving chambers for blood, so they are connected to the veins that carry blood to the heart. The ventricles are the larger, strong...
The heart functions by pumping blood both to the lungs and to the systems of the body. To prevent blood from flowing backwards or "regurgitating" back into the heart, a system of one-way valves are present in the heart. The heart valves can be broken down into two types: atrioventricular and semilunar valves. 1. Atrioventricular valves. The atriove...
The heart is able to both set its own rhythm and to conduct the signals necessary to maintain and coordinate this rhythm throughout its structures. About 1% of the cardiac muscle cells in the heart are responsible for forming the conduction system that sets the pace for the rest of the cardiac muscle cells. The conduction system starts with the pac...
- Heart anatomy. The heart has five surfaces: base (posterior), diaphragmatic (inferior), sternocostal (anterior), and left and right pulmonary surfaces. It also has several margins: right, left, superior, and inferior
- Heart valves. Heart valves separate atria from ventricles, and ventricles from great vessels. The valves incorporate two or three leaflets (cusps) around the atrioventricular orifices and the roots of great vessels.
- Blood flow through the heart. The blood flow through the heart is quite logical. It happens with the heart cycle, which consists of the periodical contraction and relaxation of the atrial and ventricular myocardium (heart muscle tissue).
- Coronary circulation. The heart must also be supplied with oxygenated blood. This is done by the two coronary arteries: left and right. Heart muscles work constantly (thank goodness!)
Oct 31, 2024 · In humans it is situated between the two lungs and slightly to the left of centre, behind the breastbone; it rests on the diaphragm, the muscular partition between the chest and the abdominal cavity. The heart consists of several layers of a tough muscular wall, the myocardium.
- The Editors of Encyclopaedia Britannica
- In humans, the heart is situated between the two lungs and slightly to the left of center, behind the breastbone. It rests on the diaphragm, the mu...
- The heart consists of several layers of a tough muscular wall, the myocardium. A thin layer of tissue, the pericardium, covers the outside, and ano...
- The pumping of the heart, or the heartbeat, is caused by alternating contractions and relaxations of the myocardium. These contractions are stimula...
- The rhythmic noises accompanying the heartbeat are called heart sounds. The two distinct sounds are heard, a low, slightly prolonged “lub” (first s...
Oct 20, 2024 · It is marked by the presence of four openings that allow blood to move from the atria into the ventricles and from the ventricles into the pulmonary trunk and aorta. Located in each of these openings between the atria and ventricles is a valve, a specialized structure that ensures one-way
Feb 24, 2021 · Function and anatomy of the heart made easy using labeled diagrams of cardiac structures and blood flow through the atria, ventricles, valves, aorta, pulmonary arteries veins, superior inferior vena cava, and chambers.
one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve atrium
