Heart Chambers and Valves Diagram PDF

Septums, Chambers and Valves of Heart 1 POSITION • Lies within the pericardium in middle mediastinum • Behind the body of sternum and the 2nd to 6th costal cartilages • In front of the 5th to 8th thoracic vertebrae • A third of it lies to the right of median plane and 2/3 to the left • Anterior t...

Septums, Chambers and Valves of Heart 1 POSITION • Lies within the pericardium in middle mediastinum • Behind the body of sternum and the 2nd to 6th costal cartilages • In front of the 5th to 8th thoracic vertebrae • A third of it lies to the right of median plane and 2/3 to the left • Anterior to the vertebral column, posterior to the sternum 2 HEART ANATOMY 3 Heart Anatomy External markings • Apex - pointed inferior region • Base - upper region • Coronary sulcus • Indentation that separates atria from ventricles • Anterior and posterior interventricular sulcus • Separates right and left ventricles Internal divisions • Atria (superior) and ventricles (inferior) • Interventricular and interatrial septa 4 External Heart: Anterior View 5 External Heart: Posterior View 6 Gross Anatomy of Heart: Frontal Section 7 Layers of the Heart Wall • Epicardium – visceral pericardium • Myocardium – cardiac muscle layer forming the bulk of the heart • Endocardium – endothelial layer of the inner myocardial surface 8 9 Structure of Heart Wall • Left ventricle – three times thicker than right • Exerts more pumping force • Flattens right ventricle into a crescent shape 10 SEPTUMS/FIBROUS SKELETON Interatrial septum • Located between right and left atria • Contains fossa ovalis Interventricular septum • Located between right and left ventricles • upper membranous part • thick lower muscular part Fibrous skeleton • Fibrous rings that surround the atrio-ventricular, pulmonary, and aortic orifices • Left and right fibrous trigons 11 Interatrial septum • Located between right and left atria • Contains fossa ovalis Interventricular septum • Located between right and left ventricles • upper membranous part • thick lower muscular part 12 Fibrous Skeleton • Surrounds all four valves • Composed of dense connective tissue • Functions • • • • Anchors valve cusps Prevents overdilation of valve openings Main point of insertion for cardiac muscle Blocks direct spread of electrical impulses 13 The Heart Chambers • Four chambers • Two atria (Right and Left) • Two ventricles (Right and Left) 14 The Heart Chambers • Atria • Features
small, thin-walled chambers • Functions
receiving chambers for blood returning to the heart from the circulation
push the blood into the adjacent ventricles. 15 The Heart Chambers • Atria • Receive blood from
Right side  Superior and Inferior Vena Cava  Coronary Sinus (draining the myocardium)
Left side  Pulmonary Veins 16 The Heart Chambers • Ventricles • Features
make up most of the mass of the heart
the walls of the left ventricle are 3X thicker than those of the right 17 The Heart Chambers • Ventricles • Functions
discharging chambers of the heart
propel blood to Pulmonary Trunk (right ventricle), Aorta (left ventricle) 18 The Right Atrium • Receives deoxygenated blood from the inferior vena cava below and from the superior vena cava above. • Receives the coronary sinus in its lower part. • The upper end of the atrium projects to the left of the superior vena cava as the right auricle. 19 The Right Atrium • The sulcus terminalis is a vertical groove on the outer surface of the atrium. This groove corresponds internally to the crista terminalis . • Above the coronary sinus the interatrial septum forms the posterior wall. The depression in the septum the fossa ovalis are presents the site of the foramen ovale. 20 21 RA 22 The Right Ventricle • Receives blood from the right atrium through the tricuspid valve . • The edges of the valve cusps are attached to chordae tendineae which are, in turn, attached below to papillary muscles. 23 The Right Ventricle • The wall of the right ventricle is thicker than that of the atria but not as thick as that of the left ventricle. • The wall contains a mass of muscular bundles known as trabeculae carneae. • The infundibulum is the smooth walled outflow tract of the right ventricle. 24 The Right Ventricle • The pulmonary valve is situated at the top of the infundibulum. • It is composed of three semilunar cusps. • Blood flows through the valve and into the pulmonary arteries via the pulmonary trunk to be oxygenated in the lungs. 25 26 RV 27 The Left Atrium • Receives oxygenated blood from four pulmonary veins which drain posteriorly. • The cavity is smooth walled except for the atrial appendage. • On the septal surface a depression marks the fossa ovalis. 28 The Left Atrium • The mitral (bicuspid) valve guards the passage of blood from the left atrium to the left ventricle. 29 LA 30 The Left Ventricle • The wall of the left ventricle is thicker than the right ventricle but the structure is similar. • The thick wall is necessary to pump oxygenated blood at high pressure through the systemic circulation. • Trabeculae carneae project from the wall with papillary muscles attached to the mitral valve cusp edges by way of chordae tendineae. 31 The Left Ventricle • The vestibule is a smooth walled part of the left ventricle which is located below the aortic valve . 32 33 LV 34 The Heart Valves • Heart valves ensure unidirectional blood flow through the heart • Composed of an endocardium with a connective tissue core. • Two major types • Atrioventricular valves • Semilunar valves 35 36 Atrioventricular (AV) Valves • Atrioventricular (AV) valves lie between the atria and the ventricles • R-AV valve = tricuspid valve • L-AV valve = bicuspid or mitral valve • AV valves prevent backflow of blood into the atria when ventricles contract • Chordae tendineae anchor AV valves to papillary muscles of ventricle wall • Prevent prolapse of valve back into atrium 37 Atrioventricular Valve 38 Semilunar Heart Valves • Semilunar valves prevent backflow of blood into the ventricles • Have no chordae tendinae attachments • Aortic semilunar valve lies between the left ventricle and the aorta • Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk • Heart sounds (“lub-dup”) due to valves closing • “Lub” - closing of atrioventricular valves • “Dub”- closing of semilunar valves 39 Semilunar Valve 40 The Heart Valves Atrioventricular valves • Right AV (Tricuspid) • separates the right atrium from the right ventricle. Prevents backflow into atrium. • Left AV (Bicuspid) • separates the left atrium from the left ventricle. Prevents backflow into atrium. Semilunar valves • Pulmonary valve • separates the right ventricle from the pulmonary arteries. Prevents backflow after ventricular contraction. • Aortic valve • separates the left ventricle from the aorta. Prevents backflow after ventricular contraction . 41 The Heart Valves Right AV (tricuspid) valve Chordai tendineae Papillary muscle Pulmonary semilunar valve Aortic semilunar valve Left AV (bicuspid) valve 42 The Heart Valves 43 Valve of pulmonary trunk: • Guards the orifice of pulmonary trunk • Has three semilunar cusps – each with free border 44 45