"The heart is subdivided into chambers by septa into right and left halves, and a constriction subdivides each half of the organ into two cavities, the upper cavity being called the atrium and the lower the ventricle. The heart, therefore, consists of four chambers:"
"The cardiac wall consists of the following layers from inside to the outside:"
"The outflow of each chamber is guarded by a heart valve:"
"The heart can be described as having the following surfaces:"
"venous blood returning from the body drains into the right atrium via the SVC, IVC and coronary sinus"
"right border: IVC, right atrium, SVC"
"superior border: right and left atria, SVC, ascending aorta and pulmonary trunk"
"Arterial supply is from the coronary arteries with coronary arterial dominance describing the dominant vessel supplying the interventricular septum. The vascular territories of the myocardium are divided into 17 myocardial segments according to the AHA nomenclature."
"Thebesian valve of the coronary sinus"
Expected headings
"Borders"
"Embryological development"
"The heart has a somewhat pyramidal form and is enclosed by the pericardium. Its base (roughly square-shaped) points posterior while its apex points to the left and inferiorly 7. It is positioned posteriorly to the body of the sternum, with one-third situated on the right and two-thirds on the left of the midline. Its left-sided orientation is formally known as laevocardia (cf. dextrocardia). The heart measures 12 x 8.5 x 6 cm and weighs ~310 g (males) and ~255 g (females) 1."
"The division of the heart into four cavities is indicated on its surface by grooves. The atria are separated from the ventricles by the coronary sulcus (atrioventricular groove); this contains the trunks of the nutrient vessels of the heart and is deficient in front, where it is crossed by the root of the pulmonary artery. The interatrial groove, separating the two atria, is scarcely marked on the posterior surface while anteriorly it is hidden by the pulmonary trunk and ascending aorta."
"The ventricles are separated by two grooves, one of which, the anterior longitudinal sulcus, is situated on the sternocostal surface of the heart, close to its left margin, the other posterior longitudinal sulcus, on the diaphragmatic surface near the right margin; these grooves extend from the base of the ventricular portion to a notch, the incisura apicis cordis, on the acute margin of the heart just to the right of the apex."
"long; formed by right atrium superiorly 7 and right ventricle inferiorly"
"shorter rounded; formed mainly by the left ventricle 7 and a little superiorly by the left atrium"
"anteriorly: the body of the sternum, and adjoining costal cartilages; left lung, and pleura (apex)"
"The ventricles are separated by two grooves, one of which, the anterior longitudinal sulcus, is situated on the sternocostal surface of the heart, close to its left margin, the other posterior longitudinal sulcus, on the diaphragmatic surface near the right margin; these grooves extend from the base of the ventricular portion to a notch, the incisura apicis cordis, on the acute margin of the heart just to the right of the apex."
"directed upward, backward and to the right"
"directed downward, forward and to the left"
"directed forward, upward and to the left"
"There is also considerable variation in the anatomy of the coronary circulation and pulmonary veins."