Cardiovascular System PDF

CARDIOVASCULAR SYSTEM By: Shiela Mae G. Bolambot, DVM CARDIOVASCULAR SYSTEM The cardiovascular system consists of the heart and a system of vessels for distribution of the blood to the tissues of the body and to the lungs for exchange of gases. Functions of the Cardiovascular syste...

CARDIOVASCULAR SYSTEM By: Shiela Mae G. Bolambot, DVM CARDIOVASCULAR SYSTEM The cardiovascular system consists of the heart and a system of vessels for distribution of the blood to the tissues of the body and to the lungs for exchange of gases. Functions of the Cardiovascular system:  convey nutrients absorbed from digestive tract to tissues  carry oxygen from:  the lungs to tissues  carbon dioxide from tissues to the lungs  remove the waste products of metabolism  transport hormones from one part of the body to another  maintain the water equilibrium of the body  keeping the normal temperature of the body  assist in overcoming disease by the antibodies contained in the blood HEART -It is located at the middle of the 4 chambers of the heart mediastinal space The heart is a cone-shaped, hollow, muscular structure located in the thorax. Pig Cattle Horse Comparative Anatomy of Chicken Goat Shee p Layers of the heart EPICARDIUM – external layer, also part of the serous layer of the pericardium MYOCARDIUM – middle and thickest layer; the actual heart muscle ENDOCARDIUM – inner layer; lines the heart chambers and valves  HEART VALVES ATRIO-VENTRICULAR VALVE (A-V)- separated by septum, prevents the backflow of blood from the ventricle to the atrium, during the ventricular systole. RIGHT ATRIOVENTRICULAR VALVE (TRICUSPID VALVE) - lies between the right atrium and right ventricle and is composed of three fibrous flaps or cusps that attach to a fibrous ring encircling the opening to the right ventricle. LEFT ATRIOVENTRICULAR VALVE ( BICUSPID VALVE OR MITRAL VALVE) -lies between the left atrium and left ventricle and is composed of two cusps SEMILUNAR VALVE - prevent the flow of blood from the vessel back into the ventricle. Composed of three half-moon-shaped cusps AORTIC VALVE -lies at the base of the aorta as it leaves the left ventricle Always remember: PULMONARY VALVE -lies at the base of the pulmonary artery as it leaves the right ventricle. TRI before you BI The Heart sound Two sound are normally heard through a stethoscope; a low slightly “lubb” sound. It is caused by the closing of mitral valve and tricuspid. A shorter high pitched “dubb” sound is caused by the closure of the aortic valve and pulmonary valve just after the end of the ventricular systole. The circulatory system consists of a network of blood vessels whose function is to transport blood around the body. All mammals have a double circulation, which consists of: Systemic circulation carries blood from the heart around the majority of the body and back to the heart. 1. Coronary circulation- supplies blood to the heart itself 2. Hepatic circulation- supplies blood to the liver. 3. Cerebral circulation- supplies arterial blood to the brain. 4. Renal circulation- supplies arterial blood to the kidney 5. Splanchnic circulation- supplies arterial blood to the digestive tract. Pulmonary circulation carries blood from the heart to the lungs and back to the heart. CIRCULATION OF BLOOD THROUGH THE HEART BLOOD is a fluid connective tissue that transports oxygen and nutrients around the body and collects waste products produced by the tissues. Functions: Blood has many functions within the body but they can be broadly divided into two groups: transport and regulation. TRANSPORT Gases in solution: Blood carries oxygenated blood from the lungs and delivers the oxygen to the tissues where it is used. It then collects deoxygenated blood containing carbon dioxide produced by the tissues during their metabolic processes, and carries it back to the lungs, where the carbon dioxide is exchanged for oxygen in the inspired air. Nutrients: Blood transports nutrients (e.g., amino acids, fatty acids and glucose), which result from the process of digestion, from the digestive system to the liver and to the tissues where they are needed. Waste products: Blood collects the waste products (e.g., urea and creatinine) resulting from metabolism in the tissues and transports them to the kidney and liver, where they are excreted from the body. Hormones and enzymes: Blood transports enzymes and hormones from the endocrine glands in which they were produced, to their target tissues REGULATION Blood plays a vital role in homeostasis by regulating: Volume and constituents of the body fluids: Blood carries water as a constituent of plasma to the tissues and is responsible for maintaining the osmotic balance of the fluids and the cells Body temperature: Blood conducts heat around the body to the body surface. Acid-base balance: Defense against infection: Blood helps to prevent infection through the action of the white blood cells, which are part of the body's immune system. Blood clotting: The clotting mechanism prevents excessive blood loss from wounds and other injuries and prevents the entry of infection. COMPOSITION OF BLOOD Plasma Plasma is the liquid part of the blood that separates out when a blood sample is spun in a centrifuge. The main constituent is water (about 90%) in which are a number of dissolved substances being transported from one part of the body to another. Blood cells The blood cells make up the solid component of blood and can be divided into three types: Erythrocytes: the red blood cells Leucocytes: the white blood cells Thrombocytes: the platelets