Cardiovascular Anatomy and Physiology

CARDIOVASCULAR SYSTEM     

A. Anatomy

              1.Layers

                   a.Pericardium: fibrous

                   b.Epicardium: covers surface of heart

                   c.Myocardium: muscular portion of the heart

                   d.Endocardium: lines cardiac chambers and covers surface of heart valves

              2.Chambers of Heart 

                   a.Right atrium: collecting chamber for incoming systemic venous system

                   b.Right ventricle: propels blood into pulmonary system

                   c.Left atrium: collects blood from pulmonary venous system

                   d.Left ventricle: thick-walled, high-pressure pump that propels blood into system

              3.Heart Valves: membranous openings that allow one way blood flow

                   a.Atrioventricular valves: prevent backflow from ventricles to atria during systole

                   b.Tricuspid - right heart valve

                   c.Mitral - left heart valve

                   d.Semilunar valves prevent backflow from aorta and pulmonary arteries into ventricles during diastole

                        1.Pulmonic

                        2.Aortic 

             4.Blood supply to heart 

                   a.Arteries

                        1.Right coronary artery supplies right ventricle and  part of left ventricle

                        2.Left coronary artery supplies mostly left ventricle

                   b.Veins

                        1.Coronary sinus veins

                        2.Thebesian veins

              5.Conduction system 

                   a.SA (Sinoatrial) node

                   b.Junctional tissue

                   c.Bundle branch Purkinje system

        

B. Physiology

              1.Function of the heart is the transport of oxygen, carbon dioxide,  nutrients and waste products

              2.Cardiac cycle consists of:

                   a.Systole - The phase of contraction during which the chambers eject blood

                   b.Diastole - The phase of relaxation during which the chambers fill with blood. When heart pumps, myocardial layer contracts and relaxes.

              3.Blood flow: 

                   a.Deoxygenated blood enters the right atrium through the  superior and inferior vena cava

                   b.Enters the right ventricle via the tricuspid valve

                   c.Travels through the pulmonic valve to pulmonary arteries and lungs

                   d.Oxygenated blood returns from lungs through the pulmonary veins into left atrium and enters the left ventricle via bicuspid (mitral) valve.

                   e.From the left ventricle, through the aortic valve through the aorta to the systemic circulation

              4.The heart itself is supplied with blood by the left and right coronary arteries

              5.The vascular system is a continuous network of blood vessels.

                   a.The arterial system consists of arteries, arterioles and capillaries and delivers oxygenated blood to tissues

                   b.Oxygen, nutrients and metabolic waste are exchanged at the microscopic level

                   c.The venous system, veins and venules, returns the blood to the heart