Heart and pericardium. Vascularization and innervation of heart. Topography of heart, its boundaries, and projection of valves of heart onto the anterior wall of thoracic cage. Tones of heart.pptx

heart function

1. The heart Heart – cor , is the muscular organ, it supplies the blood flow by own rhythmic contraction. It has conical shape and, with pericardium locates in thoracic cavity asymmetrically. The weight of heart equals 300 gr in males and, 250-270 gr in females. The longitudinal size of heart of midaged person is 10-15 cm, width 9-11 cm and, thickness 6-8 cm. The upper part of heart is called the base - basis cordis and, lower end is apex - apex cordis . There are two borders of heart: left border - margo sinister and right border - margo dexter . These borders are in contact with lungs and, because they are also called pulmonary surfaces - facies pulmonalis . Both borders separate anterior sternocostal surface of heart - facies sternocostalis from inferior diaphragmatic surface - facies diaphragmatica . In clinic practice these surfaces also known as anterior and posterior surfaces.

2. The heart There are transversely oriented coronary groove - sulcus coronarius and longitudinally located anterior and posterior interventricular grooves - sulci interventricularis anterior et posterior on the external surface of the heart. The coronary groove locates between the atria and ventricles. Right and left auricles are good visible upper than coronary groove. Right, and left coronary arteries are located in coronary groove. Interventricular grooves are at the borders of right and left ventricles. Also, great cardiac vein locates in an anterior interventricular groove and, a middle cardiac vein in a posterior interventricular groove. There is incisura apicis cordis at the connecting place of both interventricular grooves at apex cordis . The human heart consists of 4 chambers - right and left atria and, right and left ventricles.

3. The heart The atria and ventricles are separated by interatrial and interventricular septa correspondingly. Each atrium connects with the ventricle of its own side by artioventricular ostium . Inferior and superior vena cava, coronary sinus are opened into the right atrium and, pulmonary veins into the left atrium. The pulmonary trunk begins from the right ventricle and, the aorta from the left ventricle. There is venous blood in right half of the heart and, arterial blood fills the left half.

4. The heart Right atrium - atrium dextrum looks like a cube and, receives ostium venae cavae superioris from superior side and, ostium venae cavae inferioris from the posterior side. There is intervenous tubercle - tuberculum intervenosum between the ostia (Lover tubercle). Also, semilunar -shaped fold - valvula venae cavae inferioris (Eustachian valve) is observed at the inferior margin of ostium venae cavae inferioris . The left wall of the right atrium is formed by interatrial septum - septum interatriale . There is fossa ovalis on this wall which is located at the place of foramen ovale . Foramen ovale directs blood from the right atrium into the left one in fetal life. The valvula foraminis ovalis is the reason of that blood does not return from foramen ovale . After childbirth valvula compresses the foramen and closes it.

5. The heart Right atrium has anteriorly located right auricle - auricula dextra . The right atrium at the lower connects with the right ventricle by right atrioventricular ostium - ostium atrioventriculare dextrum . Between this ostium and foramen venae cavae inferioris there is ostium sinus coronarii . At the lumen of last, the valvula sinus coronarii is situated.

6. The heart The right ventricle - ventriculus dexter , is a prismatic shape, the apex of which directs inferiorly. It separates from the left ventricle by interventricular septum - septum interventriculare . The bigger inferior part of the last is muscular - pars muscularis and the upper, lesser part membranous - pars membranacea . The right atrioventricular ostium is covered by the right atrioventricular valve ( tricuspid ). The tricuspid valve consists of three cusps: anterior cusp - cuspis anterior , posterior cusp - cuspis posterior, and medial ( septal ) cusp - cuspis septalis . These cusps are formed by the internal layer - endocardium and densely connected to anulus fibrosus . To free borders of cusps chordae tendinae of papillary muscles are attached.

7. The heart With the contraction of the atria, the valves are pressed against the ventricles and do not interfere with the free flow of blood. As the ventricles contract, the valves lift and lean against each other and thus prevent the backflow of blood. There are trabeculae carneae on the wall of the right ventricle. These trabeculae are eminent into the cavity of the right ventricle. Also, papillary muscles are visible on the wall of the right ventricle.

8. The heart These are anterior, posterior, and septal (medial) papillary muscles - mm.papillares anterior, posterior et septalis . These muscles are conical shaped. The anterior surface of the right ventricle forms conus arteriosus ( infundibulum ), which passes to the pulmonary trunk. There is ostium trunci pulmonalis at the passing place of conus arteriosus to the pulmonary trunk. This ostium is covered by valva trunci pulmonalis . The valve of the pulmonary trunk consists of three valvulae - valvulae semilunaris anterior, dextra et sinistra . Their lower convex surfaces direct to the ventricle and, upper concave surfaces to the pulmonary trunk. There is nodulus valvulae semilunaris at the middle point of the free margin of each valvule . Nodulus prevents of total compression of valvulae to the wall of the vessel while blood passes from the ventricle into the pulmonary trunk- truncus pulmonalis .

9. The heart Thus lunula trunci pulmonalis is formed between the valvula and wall of the vessel, which is cleft-like. Due lunula , the returning blood fills the semilunar valvula during diastole and, turns it into sinus - sinus trunci pulmonalis . Sinuses compress each other and prevent blood from flowing back to the ventricle. The left atrium - atrium sinistrum is a cuboid shape, locates at the posterior and superior part of the heart. The cavity of the left atrium anteriorly passes to the left auricle surrounding the pulmonary trunk. There are also pectinate muscles here like in the right atrium. The foramina ( ostia ) of four veins that have no valves- ostia venarum pulmonalium are superiorly and posteriorly opened into the left atrium. The cavity of the left atrium inferiorly connects with the left ventricle by left atrioventricular ostium - ostium atrioventriculare sinistrum . This ostium is oval-shaped and narrower than the right atrioventricular ostium .

10. The heart Left ventricle - ventriculus sinister, is conical in shape, the apex of which directs inferiorly. At the base of the left ventricle, there are left atrioventricular ostium and aortic ostium . The left atrioventricular ostium is closed by the left atrioventricular valve - valva atrioventricularis sinistra ( valva mitralis ) This valve consists of two triangular-shaped cusps – cuspis anterior et posterior . Like at the right side, the base of the cusps is attached to anulus fibrosus . Chordae tendinae which start from anterior and posterior papillary muscles - mm.papillares anterior et posterior , are attached to the free margins of valves. In the wall of the left ventricle, especially at the apex, trabeculae carneae are located compactly. The wall of the left ventricle near the aortic ostium - ostium aortae is smooth. There is aortic valve - valva aortae at the initial part. This valve consists of valvula semilunaris posterior, dextra et sinistra . As well as at the right side and on the left side, there are nodulus valvulae semilunaris in the mid-point of the free margin of valvulae .

11. The heart

12. The heart The structure of the wall of the heart. The wall of the heart consists of three layers: inner - endocardium , middle – myocardium (thick) and, external - epicardium . The epicardium is the visceral plate of the serous membrane of the heart ( pericardium ). The endocardium covers the cavity of the heart from the inner side. Also, it covers the pectinate muscles, papillary muscles, trabeculae carneae , and tendinous cords. The myocardium is formed by cardiomyocytes . Between the lasts, there are discs like a network. Thus hear muscle can contract very strong as striated muscles and, in the volume of unstriated muscle. The myocardium of atria is thinner than the myocardium of ventricles.

13. The heart Thus the thickness of the myocardium of the right ventricle is 3-5 mm, but the same parameter at left ventricle is equal to 10-15 mm. There are right and left fibrous rings - anuli fibrosi dexter et sinister , surrounding the atrioventricular orifices ( ostia ) between the muscular layers of atria and ventricles. Also, there are right and left fibrous trigones – trigonum fibrosum dextrum et trigonum fibrosum sinistrum which are formed by the the connection of left fibrous ring with connective tissue, surrounding of the aortic orifice. The myocardium of atria is divided into two layers - superficial and deep. The superficial layer is the same for both atria. It consists of transverse muscular bundles. The deep layer is separate for each atrium. It is formed by circular muscular bundles that surround the orifices of vessels like a loop (as a sphincter) and, by vertical muscular bundles, beginning from fibrous rings and, forming the pectinate muscles .

14. The heart The myocardium of ventricles forms three layers: external - oblique, middle - circular and, deep - longitudinal. The oblique external muscular layer is common for both ventricles. It begins from fibrous rings and, passes to the apex of the heart. Here it forms vortex cordis and, continues as an inner longitudinal layer. The inner layer is also common for both ventricles. It takes place in papillary muscles and trabeculae carneae . Between the external and internal layers is the middle layer. The middle layer is separate for each ventricle. The external layer of the heart is the epicardium . It is a visceral layer of the serous membrane of the heart, pericardium. Epicardium covers the heart and vessels which are close to it (as the aorta, pulmonary trunk, cava veins and, pulmonary veins) and, passes to the parietal layer of the serous pericardium.

15. The heart Conduction system of the heart The regulation and coordination of the contraction of the atria and ventricles of the heart implemented by the function of atypic cardiomyocytes , that forms the conducting system of the heart. An important role in the rhythmic work of the heart is played by the conduction system of the heart. These  cells  can spontaneously produce an electrical impulse ( action potential ), that travels through the  heart  via the  electrical conduction system causing it to  contract . These cells are small-sized, long is about 25 mcm , the thickest is 10 mcm ; they have abundant innervations, connect by their endings and lateral surfaces. The conduction system of the heart consists of two: the sinuatrial , atrioventricular nodes , and the atrioventricular bundle . The sinuatrial (Keith –Flacks node )- nodus sinuatrialis is located in the wall of the right atrium, between the superior border of the superior vena cava and auricle’s atrium. The sizes of the node are the 1.0X1.0 or 2.0X1.5cm.

16. The heart Firstly the impulse has been created in this node, therefore it is called the heart’s natural pacemaker. Then impulse causes the contraction of the atrium and starts the action of the atrioventricular node. So, the activity results from the sinuatrial node degeneration at regular intervals, 70 to 80 times a minute. The atrioventricular node( Aschoff and Tawara node )- nodus atrioventricularis is located in the inferior part of the interatrial septum. During the conduction block, diseased cells cannot transmit impulses. The atrioventricular node may degenerate impulses 50 to 60 times a minute. The system impulses are conveyed in an orderly sequence from the atrioventricular node to the atrioventricular bandle or ( Hiss bandle ) - fasciculus atrioventicularis . The length of the bundle approximately is the1 cm. In the muscular part of the interventricular septum when passes from the right fibrous annulus - anulus fibrous dexter this bundle divides into two branches - crus dextrum et crus sinistrum . In the ventricles, these branches end with the Purkinje fibers - cardiac conduction myofibers .

17. The heart Pericardium The pericardium is the thin and at the same time very dense and strong fibrous- serous sac. It consists of the outer fibrous pericardium - pericardium fibrosum and, inner serous pericardium - pericardium serosum . The fibrous pericardium is made up of dense connective tissue, which is very rich in collagenous fibers and, has contact with surrounded it organs (right and left pleurae, esophagus, diaphragm, sternum, etc.). At the heart base, fibrous pericardium passes to the adventitia of the aorta, pulmonary trunk, cava veins. The serous pericardium consists of two layers which are parietal and visceral ( epicardium ) - lamina parietalis et lamina visceralis ( epicardium ) . These layers pass to each other at the heart base. Between the layers, there is a pericardiac cavity - cavitas pericardialis , which is filled by serous liquid (10-15 ml).

18. The heart The base of the pericardium is in a dense connection with the centrum tendineum of diaphragm. The apex of the pericardium surrounds the initial parts of great vessels at the heart base. Topographically pericardium divides into the anterior sternocostal part - pars sternocostalis , right and left mediastinal parts - pars mediastinalis dextra et sinistra and, diaphragmatic part - pars diaphragmatica . The sternocostal part connects with the posterior surface of the anterior wall of the thoracic cage by the sternopericardiac ligaments - ligamenta sternopericardiaca . There is a triangular-shaped space in the sternocostal part - trigonum pericardiacum

19. The heart This part has great clinical importance. Thus through this space, it is possible to puncture pericardium without opening of a pleural cavity or to provide surgical operations. Posteriorly the mediastinal part of the pericardium is in contact with esophagus, thoracic part of the aorta, azygos , and hemiazygos veins. Between the pericardium and superficial and deep vessels of the heart, there are sinuses with some certain deepness. These are transverse and oblique sinuses. The transverse sinus of the pericardium - sinus transversus pericardii , locates at the base of the heart. It is limited anteriorly and superiorly by the initial part of the aorta and pulmonary trunk. Posteriorly the anterior surface of the right atrium and superior vena cava form the boundary of the sinus. The oblique sinus of the pericardium - sinus obliquus pericardii , situates at the diaphragmatic surface of the heart. It is limited from the left side with bases of pulmonary veins and, from the right side with inferior cava vein. Anteriorly the posterior surface of the left atrium and, posteriorly - the pericardium form the boundaries of the sinus.

20. The heart Topography of heart The heart with the surrounding it pericardium locates in the middle (intermediate) part of the inferior mediastinum . The longitudinal axis of the heart forms with the body’s median line an angle which is equal to 43-48°. This axis directs from up to downward , from right to left and, from backward to forward . The 1/3 of the heart locates to the right from the midline and, 2/3 to the left from the midline. The right atrium (without auricle), interatrial septum, the lesser part of the left atrium and, those of right ventricle are at the right side and, right auricle, most parts of the left atrium and, of the right ventricle, also interventricular septum with left ventricle are at left side. There are superior, right, inferior and, left borders of projection of the heart onto the anterior thoracic wall (relative borders).

21. The heart Superior border of heart passes from line, which connects of upper borders of right and left III ribs or through II intercostal space. The right border begins by this line and, 2.0-2.5 cm to the right from the right border of the sternum. It vertically descends till the V costal cartilage (1.0-2.0 cm to the right from the right border of the sternum). The inferior border of the heart begins from V costal cartilage. It then passes from the base of the xiphoid process, mid-point of VI costal cartilage and, ends at the apex of the heart. The apex of the heart projects in V intercostal space and, 1.0-1.5 cm medial from the midclavicular line. At this place, the heartbeat can be identified. The line, which is drawn from the apex of the heart until the superior border forms of the left border of the heart. This line ends 3.0-3.5 cm to the left from the left border of the sternum.

22. The heart It is impossible to identify the relative borders of heart in practice. Due to it the topography of the sternocostal surface of the heart which has contact with the anterior thoracic wall (absolute borders) must be identified by the cardiologist. The difference between the relative and absolute borders is about the superior and right borders. Right and left the atroiventricular orifices are projected on the anterior surface of the sternum by the line which connects the sternal end of III left rib with the sternal end of VI right rib. The left atrioventricular ostium corresponds to the level of III left costal cartilage by this line and, right atrioventricular ostium to the place of connection of V right costal cartilage and sternum. The aortic’s and pulmonary trunk’s openings ( ostia ) are projected to the line which connects the sternal ends of both III costal cartilages. The pulmonary trunk ostium corresponds to the place of connection of III left costal cartilage with the sternum by this line and, the aortic ostium locates slightly posteriorly , inferiorly, and to the right. The location of the heart depends on the body type

23. The heart Thus in dolichomorphic persons the axis of the heart is vertical and, the heart looks like the hanging drop by shape ( Fig.37 ) and it is called heart-drop. In brachiomorphic persons with the more upper location of the diaphragm, the angle between the longitudinal axis of the heart and median plane is equal to 90° and, the heart receives the horizontal position (transverse or lying heart). The horizontal position of the heart is observed more frequently in females than in males. In mesomorphic persons, the heart has an oblique position. Tones of heart . The heart tones have listened to certain places: the tones of the aortic valve - in II intercostal space, at the right border of the sternum; the tones of pulmonary trunk valve - in II intercostal space, at the left border of the sternum; the tones of tricuspidal valve - at the connection place of right VI rib with the sternum (at the base of the xiphoid process); the bicuspidal valve tones - in left V intercostal space, 1.0-1.5 cm medial than the midclavicular line (at apex).

24. The heart Vessels and nerves of heart and pericardium The heart is supplied with blood by right and left coronary arteries which are the branches of the aortic bulb (initial part of the ascending aorta). The right coronary artery - a.coronaria dextra , begins from the right aortic sinus, slightly inferiorly to the upper border of the right semilunar valve. It goes to the right by the coronary sulcus and, appears at the diaphragmatic surface of the heart. The continuation of this artery is known as the posterior interventricular artery - a.interventricularis posterior . The end of the right coronary artery anastomoses with the circumflex branch of the left coronary artery. The left coronary artery - a.coronaria sinistra , separates from the left sinus of the aorta. The diameter of the left coronary artery is slightly larger than the right one. It appears superficially between the initial part of the pulmonary trunk and left auricle and, divides into anterior interventricular and circumflex branches.

25. The heart Anterior interventricular branch - r.interventricularis anterior , goes along the branch of the same name till the heart apex, and where it anastomoses with the posterior interventricular branch of the right coronary artery. Circumflex branch - r.circumflexus , locates in the coronary sulcus . Turning around the heart on the left it anastomoses with terminal branches of the right coronary artery posteriorly . Right and left coronary arteries are located in the coronary sulcus transversely and, in anterior and posterior interventricular grooves longitudinally. They form two arterial rings around the heart (transverse and longitudinal). The branches of coronary arteries provide the blood supply of all walls of the heart. In the myocardium, the level of processes of oxygenation is so high. Anastomosing microvessels repeat the direction of muscular bundles.

26. The heart There are many veins in the heart. The larger veins of the heart mainly are opened into the one venous vessel, which is the remnant of the common coronary vein - coronary sinus, sinus coronarius . The coronary sinus locates on the posterior surface of the heart and, inferiorly to the ostium of inferior vena cava. It opens into the right atrium. The following veins open into the coronary sinus: 1. Great cardiac vein - v.cardiaca magna , begins from the apex of the heart and, locates in the anterior interventricular groove, very close to the anterior interventricular branch of the left coronary artery. The great cardiac vein receives the venous blood from anterior surfaces of both ventricles and, interventricular septum. 2. Middle cardiac vein - v.cardiaca media , begins from the apex of the heart and, opens into the coronary sinus.

27. The heart 3. Small cardiac vein - v.cardiaca parva , begins from the pulmonary surface of the right ventricle and, opens into the coronary sinus. It mainly collects the venous blood from the right half of the heart. 4. Posterior vein of left ventricle - v.posterior ventriculi sinistri , is formed by the connection of several veins on the posterior surface of the left ventricle close to the apex of the heart. It passes into the coronary sinus or the great cardiac vein. 5. Oblique vein of left atrium - v.obliqua atrii sinistri , directs from up to down on the posterior surface of the left atrium and, opens into the coronary sinus. Some veins are directly opened to the right atrium. These are anterior cardiac veins - vv.cardiacae anteriores , which collect the venous blood from the anterior wall of the right ventricle. The smallest cardiac veins - vv.cardiacae minimae , 20-30 in number and, locate inside of heart wall. They open onto the right atrium, partly into the ventricles, even into the left atrium.

28. The heart The lymph flow of the heart wall consists of located like the network of lymph capillaries in the endocardium , myocardium, and epicardium . Lymph produced in the endocardium and myocardium flows into lumens of lymph plexuses by lymph capillaries in the epicardium . Lymph vessels form two main vessels of the heart. The left cardiac lymph vessel is formed by the connection of lymph vessels of anterior surfaces of both ventricles, left pulmonary vessels, and lymph vessels of the posterior surface of the left ventricle, and opens into inferior tracheobronchial lymph nodes. The right cardiac lymph vessel is formed by the connection of lymph vessels of anterior and posterior surfaces of the right ventricle and opens into one of the anterior mediastinal lymph nodes.

29. The heart The nerves of the heart. The heart is innervated by the sympathetic, parasympathetic, and sensory nerve fibers. The sympathetic fibers within the cardiac nerves from the right and left sympathetic trunks to carry out the impulses which cause the heart’s faster contraction and, enlargement of the lumen of coronary arteries. Parasympathetic fibers (the cardiac branches of the vagus nerve) send the impulses for decreasing heart contraction and, constriction of the lumen of coronary arteries. Sensory fibers within the cardiac nerves and their branches begin from the wall of the heart and receptors of the vessel of the heart and, pass to the corresponding centers of the spinal cord and brain. The sympathetic nerves of the heart (superior, middle, and inferior cervical, also thoracic nerves) begin from all cervical and upper thoracic ganglia of right and left sympathetic trunks. The parasympathetic nerves of the heart are the branches of the vagus nerve.

30. The heart The innervation scheme of the heart (by Vorobyov ). The nerves which are directed to the heart form the extraorganic cardiac plexuses near the aortic arch and pulmonary trunk (superficial and deep). The intraorganic plexuses are located in the heart wall, within all coats. Extraorgan superficial cardiac plexus locates on the anterior surface of the pulmonary trunk and, below than aortic arch. Extraorgan deep cardiac plexus locates behind the aortic arch ( anteriorly to tracheal bifurcation). The extraorganic superficial cardiac plexus is formed by the left superior cervical cardiac nerve (from left superior cervical sympathetic ganglion) and, left superior cervical cardiac branch (from left vagus nerve). All other nerves and branches are ended in the extraorganic deep cardiac plexus.

31. The heart The branches of the extraorganic cardiac plexuses pass to the intraorganic cardiac plexus. The last one divides into subepicardial , intramuscular and, subendocardial plexuses. There are cardiac ganglia - ganglia cardiaca within the intraorganic cardiac plexus. These ganglia belong to the vegetative nervous system. The nerve cell is more numerous in subepicardial plexus. According to Vorobyov the nerves within the subepicardial plexus are located like ganglionic branches and, innervate the certain regions of the heart. According to that 6 subepicardial plexuses are identified. 3 plexus are on the anterior surface of the heart and, 3 are on the posterior.

32. The heart 1) Right anterior; 2) Left anterior - both are located at both sides of conus arteriosus , below than epicardium and, in anterior and lateral walls of right and left ventricles. 3) anterior plexus of the atria is situated in the anterior wall of the atria; 4) right posterior plexus passes from the posterior wall of the right atrium to the posterior wall of the right ventricle (it gives off branches for the sinoatrial node of the conducting system of the heart); 5) left posterior plexus extends down from the lateral wall of the left atrium to the posterior wall of the left ventricle; 6) posterior plexus of the left atrium (plexus of Hallerian sinus) locates in the posterior wall of the upper part of the left atrium (at the regions of the ostia of pulmonary veins).

33. The heart Vascularization and innervation of the pericardium . The pericardium is supplied by the pericardial branches of the thoracic aorta and the pericardodiaphragmatic artery from the internal thoracic artery ( subclavian artery). The veins of the pericardium correspond to arteries of the same name. They are opened into the brachiocephalic veins, azygos , and hemiazygos veins. Lymph vessels are opened into lateral and anterior pericardial lymph nodes and, also into anterior and posterior mediastinal lymph nodes. The pericardium is innervated by the branches of phrenic and vagus nerves and, by cervical and thoracic cardiac nerves, separating from corresponding ganglia of right and left sympathetic trunks.