Heart (cor) is a key element of the cardiovascular system, providing blood flow in vessels, and is a hollow muscular organ conical shape, which is located behind the breastbone in the center of the diaphragm tendon, between the right and left pleural cavity. Its weight is 250-350, the distinguishing feature is the ability of automatic action.

The heart is surrounded by the pericardium - the pericardium (pericardium), which separates it from other organs, and is secured by means of the blood vessels. In the isolated pericardium of the heart base (basis cordis) - caudineural of communicating with large vessels, and the tip of the heart (apex cordis) - freely dispose of anteroinferior part. Flattened surface lowback adjacent to the diaphragm and diaphragmatic surface is (facies diaphragmatica), a convex surface directed peredneverhnyaya to the sternum and costal cartilages, and is called sternocostal surface (facies sternocostalis). The borders of the heart are projected from the top in the second quadrant, the right act at 2 cm over the right edge of the sternum, the left does not reach 1 cm to mid-clavicular line, the tip of the heart lies in the fifth left intercostal space.

On the surface of the heart, there are two longitudinal grooves - the anterior interventricular sulcus (sulcus interventricularis anterior) and posterior interventricular groove (sulcus interventricularis posterior), bordering the heart of the front and rear, and lateral furrow crown (sulcus coronaris), passing a ring. The final table is its own blood vessels of the heart.

The heart is divided into four chambers: right atrium, right ventricle, left atrium and left ventricle. Longitudinal septal (septum interatriale) and interventricular septum (septum interventriculare) cavity and ventricles are separated into two separate halves. The upper chamber (atrium) and lower (ventricle) of each half of the heart are separated by atrio-ventricular septum (septum atrioventriculare).

Wall of the heart consists of three layers: the outer one - epicardium, the middle - the myocardium, the inner - endocardium.

In Fig. 210.
The position of the heart
1 - left subclavian artery;
2 - right subclavian artery;
3 - schitosheyny barrel;
4 - left common carotid artery;
5 - brachiocephalic trunk;
6 - aortic arch;
7 - upper hollow Vienna;
8 - pulmonary trunk;
9 - pericardium;
10 - left ear;
11 - the right ear;
12 - arterial cone;
13 - the right lung;
14 - left lung;
15 - right ventricle;
16 - left ventricle;
17 - apex of the heart;
18 - pleura;
19 - Iris
In Fig. 211.
The muscular layer of the heart
1 - right pulmonary veins;
2 - left pulmonary veins;
3 - upper hollow Vienna;
4 - aortic valve;
5 - left ear;
6 - valve pulmonary trunk;
7 - middle muscular layer;
8 - interventricular sulcus;
9 - internal muscle layer;
10 - deep muscle layer

Epicardium (epicardium) is part of a serous membrane, composed of two sheets: the external - the pericardium, or the pericardium, and the internal (visceral) - directly epicardium, which completely surrounds the heart and tightly soldered to it. The outer sheet goes into the inner place of discharge from the large vessels of the heart. Lateral sides of the pericardium adjacent to the pleural bags, front attached to the sternum connecting fibers, and bottom - to the center of the diaphragm tendon. Between sheets of pericardium is fluid, moistening the surface of the heart and reduces friction when it cuts.

Myocardium (myocardium) is the muscle membrane, or heart muscle, which runs continuously almost independently of the will of man and has a high resistance to fatigue. Atrial muscle layer is thin enough, which was caused by a small load. On the surface of the ventricles are fiber, grasping at once both ventricles. Most fat is muscle layer of the left ventricle. Ventricular wall formed by three layers of muscle: an outer longitudinal, middle circular and inner longitudinal. The fibers of the outer layer, deepening on the bias, are moving into the fibers of the middle layer, and those - in the inner fibers.

Endocardium (endocardium) densely fused with muscle layer and lines the cavity of all hearts. In the left chambers of the heart endocardium much thicker, especially in the interventricular septum and openings around the aorta. In the right endocardium thickens cells in the pulmonary trunk openings.

List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)