Chambers of Heart 15- 12 - 2008

Heart The heart is a hollow muscular organ Shape of the heart: pyramid shaped with three surfaces and apex. Surfaces of the heart: sternocostal surface: Formed mainly by the right atrium and the right ventricle diaphragmatic surface: Formed mainly by the right and left ventricle posterior surface (base of the heart): Formed mainly by the left atrium lies opposite the apex Apex: formed by the left ventricle lies at the 5th intercostal space

CHAMBERS and VALVES OF HEART The heart is divided by the vertical septa into four chambers: -right and left atria -right and left ventricles Valves: Tricusped valve ( the cusps give attachment to chordae tendinae) the mitral valve Aortic valve Pulmonary valve Cardiac muscle: Myocardium Epicardium Endocardium

Right atrium

Right Atrium The RA divided into two parts: Posterior part called the sinus venarum Anterior part called atrium proper is rough wall And appendage called the auricle Sulcus terminalis:this groove lies Outside of the heart:At the junction between the right atrium and the right auricle is a vertical groove. Inside the heart The vertical groove forms a ridge (cristae terminalis) The part lies posterior to the ridge is smooth(derived embryologically from the sinus venosus) The part in front of the ridge is rough(trabeculated) by muscle ,the Muscle pectinati

Opening into the Right Atrium - superior vena cava: Opens into the upper part of RA(it has no valve) -inferior vena cava: Opens into the lower part of RA Coronary sinus: Opens between the inferior vena cava and the atrio ventriclular orifice drains most of the blood from the heart wall Atrioventricular orifice: anterior to the inferior vena cava opening (guarded by tricusped valve) Small orifice of small veins Opens into the RA

Inter atrial septum,fossa ovalis A depression seen on the atrial septum It is oval in shape with a margin called limbus fossa ovalis In fetus it serves as a communication between right and left atrium In adult it is closed and appears as a depression called as fossa ovalis

Cavity of right ventricle&semilunar valves

Right ventricle Papillary muscles and valves Right atrioventricular orffice is guarded by three valves named as tricuspid valve Tricuspid valves are classified into anterior and posterior and septal based on anatomical position The margins of the valves attached to chordatendinae which are continuation of the papillary muscle The largest trabiculae which extends from the interventricular septum to the anterior papillary muscle is called septomarginal trabcula (moderator band) Trabaculaes are irregular muscular elevation of myocardium which projects into the lumen of both ventricles

Trabaculae carnae,pulmonary valves,papillary muscles&corda tendinae

Pulmonary valves Pulmonary valves are located at the upper end of the right ventricular It is placed between R.V and the pulmonary trunk The orifice is about 3 cm in diameter and is guard by pulmonary valves also called semilunar valves It has one anterior cusp and two posterior cusp

Left atrium& Left ventricle

Cavity of left ventricle & mitral valve

Left atrium & mitral valve

Left ventricle (mitral and aortic valve) The inner surface of left ventricle is almost similar features It has got an inflow tract (left atrioventricular orifice) and outflow tract (aortic orifice) Trabaculae carneae are irregular muscular ridges The mitral orifice is guarded by two valves (bicuspid) -one anterior and one posterior the valves attached to the papillary muscle through the chordaetendinae The outflow tract is guarded by aortic valves (semilunar valves)which leads into the ascending aorta They are two anterior and one posterior cusp

Arterial supply of the heart Blood supply of the heart by: Right and left coronary arteries (which arise from the ascending aorta) Branches of the Right coronary artery: -Right conus artery -Anterior ventricular branches ( gives the marginal branch) -posterior ventricular branches Posterior interventrcular (descending artery) -The atrial branches

Left coronary artery Larger than the right coronary artery Supply the major part of the heart Branches: Anterior interventricular (descending) -gives left diagonal artery and left conus artery -circumflex artery gives left marginal artery and Ant and post ventriclar branches

Venous drainage of heart Most blood from the heart wall drains into the RA through the coronary sinus (which is a continuation of great cardiac vein). Great cardiac vein: It open into the RA to the left ofthe inferior vena cava Small and middle cardiac vein Anterior cardiac vein

Nerve supply of the heart The heart is innervated by: Cardiac plexuses (fibers of autonomic nervous system) Sympathetic fibers (from cervical and upper portion of thorax) Parasympathetic fibers (from the vagus nerve) Situated below the arch of Aorta Action of heart Cardiac cycle( normal beats 70-90 per minutes for adult and 130-150 for newborn child)

Fetal Remnants Fossa ovalis: Anulus ovalis: Is a shallow depression (which is the site of foramen ovale in the fetus) Anulus ovalis: forms the upper margin of the fossa These strucures lie on the atrial septum (which separates the right atrium from the left atrium)

And wishing you happy EID THANK YOU And wishing you happy EID Dr. kumar Associate professor Dr. Mashair Abdelrhman