General Anatomy for Dentistry Lecture 5: Cardiovascular System PDF

General anatomy for Dentistry Lecture 5: Cardiovascular system (CVS) By: Rasha Mohamed Elshinety; MD. PhD Professor of Human Anatomy & Embryology Components of the cardiovascular system (CVS):  Heart and pericardium  Blood vessels (arteries, veins an...

General anatomy for Dentistry Lecture 5: Cardiovascular system (CVS) By: Rasha Mohamed Elshinety; MD. PhD Professor of Human Anatomy & Embryology Components of the cardiovascular system (CVS):  Heart and pericardium  Blood vessels (arteries, veins and capillaries) Heart:  The heart is a hollow muscular organ.  It pumps blood to the body and lungs.  It receives blood from the body and lungs.  It is covered with the pericardium. Pericardium:  It is the covering of the heart.  Fibrous pericardium  Serous pericardium; It consists of 2 layers: 1. Parietal layer (outer) 2. Visceral layer (inner) Heart:  It presents in the thorax between the two lungs.  It is conical in shape.  It has apex, base, 2 surfaces.  It consists of 4 chambers; 2 atria (right and left) and 2 ventricles (right and left).  Each atrium has a small outgrowth (extension); the auricle Heart:  The right side is completely separated from the left side by the septa.  The septum between the right and left atria is the interatrial septum.  The septum between the right and left ventricles is the interventricular septum.  Each atrium and ventricle in the same side has a valve in between. Heart Atria  Right atrium receives: 1. Superior vena cava 2. Inferior vena cava  Left atrium revives:  4 pulmonary veins  The 2 atria are completely separated by the interatrial septum. Ventricles  Right ventricle gives:  Pulmonary trunk  Left ventricle gives:  Aorta  The 2 ventricles are completely separated by the interventricular septum. Apex of the heart:  It is made by the left ventricle.  It lies 3 ½ inches from the midline in the left 5th intercostal space. Valves of the heart:  Aortic valve:  Mitral (bicuspid) valve:  Between the aorta and left  Between the left atrium and left ventricle ventricle.  Pulmonary valve:  Tricuspid valve:  Between the pulmonary trunk and  Between the right atrium and right right ventricle ventricle.  These valves permit blood to go  These valves permit blood to pass from the ventricles to the arteries from the atrium to the ventricle in only and not in the opposite the same side only and not in the direction. opposite direction. Blood supply of the heart:  Coronary arteries  Coronary sinus Coronary arteries:  They are 2 (right and left coronary arteries).  They arise from the beginning of aorta (ascending aorta).  The right coronary gives the marginal and posterior interventricular arteries.  The left coronary gives the circumflex and anterior interventricular arteries. Coronary sinus:  It receives all venous drainage of the heart.  It ends in the right atrium. Conducting system of the heart:  s a network of specialized cardiac muscle cells that initiate and transmit the electrical impulses responsible for the coordinated contractions of each cardiac cycle.  Sinoatrial node (SA node)  Atrioventricular node (AV node)  Bundle of His  Right and left bundle branches  Purkinje fibers Types of circulation: 1. Systemic circulation 2. Pulmonary circulation 3. Portal circulation Systemic circulation:  Circulation of blood between heart and the whole body.  Oxygenated blood is pumped to the body through aorta.  Deoxygenated blood is drained to the heart from the body through SVC, IVC Pulmonary circulation:  Circulation of blood between heart and the lungs.  Oxygenated blood is received from the lungs to the heart through 4 pulmonary veins.  Deoxygenated blood is pumped to the lungs from the heart through pulmonary trunk Portal circulation:  The circulation of blood between the gastrointestinal tract and liver through portal vein. Blood vessels:  All arteries carry oxygenated blood EXCEPT pulmonary trunk  All veins carry deoxygenated blood EXCEPT 4 pulmonary veins  Blood capillaries are very small vessels that connect the ends of the arteries and veins.