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Human cardiovascular system, body organ mechanism that conveys blood via vessels to and also from all components of the body, moving nutrients and also oxygen to tproblems and also rerelocating carbon dioxide and also other wastes. It is a closed tubular mechanism in which the blood is moved by a muscular heart. Two circuits, the pulmonary and the systemic, consist of arterial, capillary, and also venous components.


The vascular mechanism is a netjob-related of arteries, veins, and capillaries that supplies blood to the tproblems of the body.

The main attribute of the heart is to serve as a muscular pump propelling blood right into and also via vessels to and also from all components of the body. The arteries, which get this blood at high press and velocity and also conduct it throughout the body, have actually thick wall surfaces that are written of elastic fibrous tissue and muscle cells. The arterial tree—the branching mechanism of arteries—terminates in short, narrowhead, muscular vessels referred to as arterioles, from which blood enters basic endothelial tubes (i.e., tubes created of endothelial, or lining, cells) well-known as capillaries. These thin, microscopic capillaries are permeable to vital cellular nutrients and waste products that they obtain and distribute. From the capillaries, the blood, now depleted of oxygen and also burdened via waste products, relocating even more slowly and also under low press, enters little vessels referred to as venules that converge to develop veins, inevitably guiding the blood on its method back to the heart.


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The Person Body
You might understand that the huguy brain is created of 2 halves, yet what fractivity of the human body is comprised of blood? Test both halves of your mind in this humale anatomy quiz.

This write-up defines the framework and also function of the heart and also blood vessels, and the innovations that are offered to evaluate and also monitor the wellness of these standard components of the humale cardiovascular system. For a discussion of diseases affecting the heart and also blood vessels, see the article cardiovascular illness. For a complete therapy of the composition and physiologic function of blood, see blood, and also for more indevelopment on diseases of the blood, see blood illness. To learn more about the human circulatory mechanism, see systemic circulation and pulmonary circulation, and also for even more around cardiovascular and also circulatory feature in other living organisms, see circulation.

The heart


Shape and also location


Explore the huguy heart and also exactly how the cardiovascular device assist circulate blood throughout the body
The heart, located in between the lungs, powers the circulatory mechanism.
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The adult humale heart is typically slightly larger than a clenched fist, through average dimensions of about 13 × 9 × 6 cm (5 × 3.5 × 2.5 inches) and also weight approximately 10.5 ounces (300 grams). It is cone-shaped, with the wide base directed upward and to the best and the apex pointing downward and to the left. It is situated in the chest (thoracic) cavity behind the breastbone (sternum), in front of the windpipe (trachea), the esophagus, and also the descfinishing aorta, between the lungs, and also above the diaphragm (the muscular partition between the chest and also abdominal cavities). About two-thirds of the heart lies to the left of the midline.


The heart is suspended in its very own membranous sac, the pericardium. The solid outer portion of the sac, or fibrous pericardium, is firmly attached to the diaphragm listed below, the mediastinal pleura on the side, and also the sternum in front. It gradually blends via the coverings of the remarkable vena cava and also the pulmonary (lung) arteries and veins causing and from the heart. (The space in between the lungs, the mediastinum, is bordered by the mediastinal pleura, a continuation of the membrane lining the chest. The exceptional vena cava is the principal channel for venous blood from the chest, arms, neck, and head.)

Smooth, serous (moisture-exuding) membrane lines the fibrous pericardium, then bends ago and covers the heart. The percentage of membrane lining the fibrous pericardium is well-known as the parietal serous layer (parietal pericardium), that covering the heart as the visceral serous layer (visceral pericardium or epicardium).

The two layers of serous membrane are usually separated by only 10 to 15 ml (0.6 to 0.9 cubic inch) of pericardial liquid, which is secreted by the serous membranes. The slight room produced by the separation is referred to as the pericardial cavity. The pericardial liquid lubricates the two membranes through eexceptionally beat of the heart as their surdeals with glide over each other. Fluid is filtered right into the pericardial area via both the visceral and also parietal pericardia.

Chambers of the heart

The heart is divided by septa, or partitions, right into ideal and also left halves, and also each fifty percent is subdivided right into 2 chambers. The top chambers, the atria, are separated by a partition recognized as the interatrial septum; the lower chambers, the ventricles, are separated by the interventricular septum. The atria obtain blood from assorted parts of the body and pass it into the ventricles. The ventricles, in turn, pump blood to the lungs and to the remainder of the body.

The ideal atrium, or appropriate remarkable percentage of the heart, is a thin-walled chamber receiving blood from all tconcerns other than the lungs. Three veins empty into the right atrium, the exceptional and also inferior venae cavae, bringing blood from the upper and lower sections of the body, respectively, and also the coronary sinus, draining blood from the heart itself. Blood flows from the ideal atrium to the ideal ventricle. The right ventricle, the ideal inferior percentage of the heart, is the chamber from which the pulmonary artery carries blood to the lungs.

The left atrium, the left remarkable portion of the heart, is slightly smaller than the appropriate atrium and also has a thicker wall. The left atrium receives the 4 pulmonary veins, which bring oxygenated blood from the lungs. Blood flows from the left atrium into the left ventricle. The left ventricle, the left inferior percentage of the heart, has actually walls three times as thick as those of the best ventricle. Blood is required from this chamber through the aorta to all parts of the body except the lungs.

External surface of the heart

Shenable grooves dubbed the interventricular sulci, containing blood vessels, mark the separation between ventricles on the front and also back surencounters of the heart. There are two grooves on the exterior surchallenge of the heart. One, the atrioventricular groove, is along the line wright here the appropriate atrium and the ideal ventricle meet; it includes a branch of the ideal coronary artery (the coronary arteries deliver blood to the heart muscle). The other, the anterior interventricular sulcus, runs along the line between the right and left ventricles and has a branch of the left coronary artery.

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On the posterior side of the heart surface, a groove dubbed the posterior longitudinal sulcus marks the department between the best and also left ventricles; it consists of another branch of a coronary artery. A fourth groove, between the left atrium and also ventricle, holds the coronary sinus, a channel for venous blood.