Cardiovascular System Examination — Anatomy, OmpathStudy

Cardiovascular System Examination — Complete Study Guide Clinical Methods and Communication Carey Francis Okinda March/April 2012 Examination of the Cardiovascular System – 10 hours Unit Outline 1) Review of anatomy and physiology - 2 hours 2) History taking - 1 hour 3) Introduction and general examination - 2 hours 4) Inspection and Palpation - 2 hours 5) Percussion and Auscultation - 2 hours 6) Investigations and therapeutic procedures - 1 hour Topic 1: Review of Anatomy and Physiology Objectives At the end of the lesson the learner will be able to: - 1) Describe the structure of the organs of the cardiovascular system 2) Describe the functions of the cardiovascular system 3) Explained the functional organization of the cardiovascular system 1.0 Introduction The Circulatory system is a continuous circuit comprising of the cardiovascular system (heart and blood vessels) and lymphatic system (lymph vessels, lymph nodes and lymphoid-organs -spleen, thymus and tonsils). Blood serves numerous functions including the transport of respiratory gases, nutritive molecules, metabolic wastes and hormones. Blood is transported through the body in a system of vessels leading from and returning to the heart. Figure 1.1: The Cardiovascular system Functions of the Circulatory System 1) Transportation Respiratory - red blood cells (erythrocytes) transport oxygen to tissue cells and carbon dioxide is transported by blood to the lungs foe elimination Nutritive - blood carries absorbed products of digestion through the liver to body cells Excretory - metabolic wastes, excessive water and ions are filtered through the capillaries of the kidney and excreted in urine 2) Regulation Blood carries hormones and other regulatory molecules from the site of origin to target tissues 3) Protection Protects against injury and foreign microbes or toxins Clotting mechanism prevents blood loss when vessels are damaged Leucocytes (white blood cells) provide immunity THE CARDIOVASCULAR SYSTEM Is made up of the heart and blood vessels The Heart The heart is a four chambered; double pump that keeps blood flowing through the circulation and a normal heart weighs 250 – 350 g in an adult. Its pumping action creates the pressure needed to push blood in the vessels to the lungs and body cells. The function of the heart is to pump sufficient oxygenated blood containing nutrients, metabolites and hormones to meet the moment to moment metabolic needs and preserve a constant milieu. The flow of blood through the circulatory system is made possible by the pumping action of the ventricles and atria Figure 2: The Heart The Heart Pump The heart has 2 main pumps that operate as connected in series i.e. the left pump (for the peripheral organs) and the right pump (for the lungs). The right and left pumps are separated by a muscular wall (septum) which prevents mixing of blood from the two sides of the heart. Each pump has 2 chambers (the ventricle and the atria). In detail the heart has 4 pumps of which 2 are primer pumps (the atria) and 2 power pumps (the ventricles). The atria receive blood from the venous system then pump it into the ventricles which pump blood into the arterial system. The Heart Valves Normal functioning of the heart depends on the mechanical efficiency of the 4 valves namely aortic valve, mitral valve, tricuspid valve and pulmonary valve. The atrioventricular valves (mitral and tricuspid valves) consist of 4 kinds of structures namely an annulus ring, cusps, papillary muscles and chordae tendinae. Normal functioning depends on the mechanical efficiency of the cusps, chordae tendinae, papillary muscles, pliability and size of the fibrous ring or annulus and adequacy of left ventricular contraction. The semi-lunar valves (aortic and pulmonary valves) each consist of 2 kinds of structures namely an annulus and semi-lunar cusps The Conducting System The contraction and relaxation of the heart’s musculature is highly coordinated during the cardiac cycle. The coordination is controlled by a system of highly specialized myocardial cells (the conducting system). The conducting system provide a nodular cluster of cells which initiate the conduction signal and supplies cellular tracts to propagate this signal through the atria and ventricular musculature. The 3 parts of the conducting system found in the walls of the right atrium are: - sino-atrial node (SAN), the internodal tracts and atrio-ventricular node (AVN). The atrioventricular (AV) bundle (bundle of his) is a tract of cells originating from the AV node and passing through an opening in the fibrous annulus of tricuspid valve extending through the membranous part of the inter-ventricular septum. At the boarder between membranous and muscular parts of the inter-ventricular septum it divides into 2 major branches (left and right bundle branches). Purkinje fibres are the terminal cells of the conducting system in both ventricles. They are very large diameter cells whose terminal process ends in