Heart and Blood Vessels PDF

Heart and blood vessels Prof.dr Marija Papazova Heart and blood vessels The heart is the main organ of cardiovascular system. It is located behind the sternum in the middle inferior mediastinum. The cardiac axis connects the opening of the superior vena cava with the apex of the heart; it direc...

Heart and blood vessels Prof.dr Marija Papazova Heart and blood vessels The heart is the main organ of cardiovascular system. It is located behind the sternum in the middle inferior mediastinum. The cardiac axis connects the opening of the superior vena cava with the apex of the heart; it directs diagonally, ventrally and caudally.  EXTERNAL HEART MORPHOLOGY  sides  facies sternocostalis  facies diaphragmatica  facies pulmonalis  borders  Left superior, left inferior and right border  EXTERNAL HEART MORPHOLOGY  (basis cordis)-  Apex cordis 1.Base of heart (basis cordis) – faces superiorly, posteriorly and medially. The location of the great vessels entering and leaving the heart. 2.Apex of heart (apex cordis) faces inferiorly, anteriorly and laterally. Touches the thoracic wall at the 5th intercostal space in the midclavicular line.  EXTERNAL HEART MORPHOLOGY  sulcus coronarius  sulcus interventricularis anterior  sulcus interventricularis posterior  Sulcus terminalis cordis  Internal heart morphology  atrium dextrum  ventriculus dexter  atrium sinister  ventriculus sinister The heart consists of four chambers separated by septa and valves. From the clinical and functional viewpoint, the heart is divided into the right heart and the left heart. The pericardium is a firm sac composed of two sheets that are separated by 15-50 ml of serous fluid, enabling smooth heart movements.  Internal heart morphology  (atrium dextrum)  6 walls Blood from the systemic circulation flows through the superior and inferior vena cava into the atrium. The tricuspid valve directs blood from the right atrium into the right ventricle.  Internal heart morphology  ventriculus dexter  base  ostium atrioventriculare dextrum  ostium trunci pulmonalis  apex  3 sides Blood flows through the pulmonary valve to the pulmonary trunk and consequently throughout the entire pulmonary circulation where gas exchange takes place. The right ventricle pumps against the relatively low pulmonary blood pressure of around 20 mmHg.  ATRIUM SINISTRUM  (venae pulmonales)  (ostium atrioventriculare sinistrum) Oxygenated blood from the pulmonary circulation flows through the four pulmonary veins to the left atrium and then through the mitral valve to the left ventricle.  VENTRICULUS SINISTER  Base  ostium atrioventriculare sinistrum  оstium aortae  Apex  2 sides Blood is ejected through the aortic valve into the ascending aorta and then flows throughout the entire systemic circulation. The left ventricle pumps blood against the relatively high systemic blood pressure.  Valves The valves are fibrous plates separating the atria from the ventricles and the ventricles from the great vessels leaving the heart. Characterised by their shape, location and dynamics, they are divided into cuspidate and semilunar valves. The cuspidate valves are opened by blood flowing from the atrium into the ventricle and are closed during ventricular systole. The semicircular valves are pushed open as blood flows into the aorta and pulmonary trunk during ventricular systole. During ventricular diastole blood flows into the heart and the semilunar valves close.  Cardiac skeleton  Four fibrous rings  The fibrous triangles The components of the cardiac skeleton are fibrous rings of the valves, the fibrous triangles, the membranous part of the interventricular septum, which is located perpendicularly to the plane of the valves and the tendon of the infundibulum.  Conducting system of the heart (SYSTEMA CONDUCENS CORDIS)  nodus sinoatrialis Keith - Flack)  fasciculus atrioventricularis - His)  nodus atrioventricularis – Aschof-Tavara  Branches of Purkinje  Conducting system of the heart The heart has the capacity to generate and conduct electric impulses. These impulses are produced in the sinoatrial node in the right atrium. They pass through the atria to the atrioventricular node and then pass through the bundle of His to reach the ventricles. After passing through the atrioventricular septum, the bundle of His divides into the right and left bundles of Tawara, which carry the impulses down the interventricular septum and into the left and right ventricles. The final branches of the cardiac conducting system are the subendocardial branches of Purkinje, which spread the impulses throughout the ventricular muscle.  HEART VASCULARISATION A. coronaria dextra A. coronaria sinistra Sinus coronarius  HEART INERVATION  Plexus cardiacus:  Nervus cardiacus cervicalis superior, medius, inferior – sympaticus  Rami cardiaci superiores et inferiores – n. vagus ( parasympathicus)  PERICARDIUM  Pericardium serosum  lamina visceralis s.epicardium  lamina parietalis Pericardium fibrosum  Cavum pericardii