cardiovascular system

• Cardiovascular system is sometimes called as the blood vascular or simply the circulatory system

  
• Cardiovascular system

  Consists of the blood, which is a fluid that transports nutrients and waste products to and from the cell. They are being circulated by the heart, which is a muscular pumping device, and a closed system of blood vessels, specifically arteries, veins and capillaries

  
• The blood contained in the circulatory system is pumped by the heart around a closed circle or circuit of vessels as it passes again and again to the various circulations of the body

  
• Heart


  • Pumps blood continuously to the body's blood vessels so that blood can reach body cells and exchange materials with them

  
• The heart beats about 100,000 times per day, 35 million beats per year, and 2.5 billion times in an average lifetime
• The left side of the heart pumps blood through an estimated 100,000 kilometers or 60,000 miles of blood vessels (equivalent to traveling around the Earth's equator about three times)

  
• The right side of the heart pumps blood to the lungs, enabling blood to pick up oxygen and unload carbon dioxide
• Even while you are sleeping, your heart pumps 30 times its own weight each minute, which amounts to about 5 liters (5.3 qt) to the lungs and the rest of the body, 14,000 liters (3600 gallons) of blood per day, and 5,000,000 (1.3 million gallons) liters per year
• Cardiology


  The scientific study of the normal heart and the diseases associated with it, including medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology

  
• Cardiologists


  Physicians who specialize in the field of cardiology, a specialty of internal medicine
• Heart


  • Relatively small, roughly the same size as your closed fist, about 12 cm (5 in.) long, 9 cm (3.5 in.) wide at its broadest point, and 6 cm (2.5 in.) thick, with an average mass of 250 g (8 oz) in adult females and 300 g (10 oz) in adult males
• Mediastinum


  An anatomical region that extends from the sternum to the vertebral column, from the first rib to the diaphragm, and between the lungs

  
• About 2/3 of the mass of the heart lies to the left of the body's midline

  
• Heart

  Can be visualized as a cone lying on its side, with the pointed apex formed by the tip of the left ventricle, a lower chamber of the heart, and resting on the diaphragm. It is directed anteriorly, inferiorly and to the left

  
• Base of the heart

  Opposite the apex and is its posterior aspect, formed by the atria (upper chamber) of the heart, mostly the left atrium

  
• Apex of the heart


  Formed by the tip of the left ventricle, directed anteriorly, inferiorly, and to the left

  
• Heart


  • Generates blood pressure which is responsible for moving blood to the blood vessels
  • Separates the pulmonary and systemic circulations and ensures better oxygenation of the blood flowing to the tissues
  • Ensures one way blood flow through the valves
  • Regulates blood supply by changing the rate and force of contractions to meet the metabolic needs of tissues

  
• Pericardium


  The membrane that surrounds and protects the heart, confining it to its position in the mediastinum while allowing sufficient freedom of movement for vigorous and rapid contraction

  
• Fibrous pericardium


  • Composed of tough, inelastic, dense irregular connective tissue, resembling a bag that rests on and attaches to the diaphragm. It prevents overstretching of the heart, provides protection, and anchors the heart in the mediastinum

  
• Parietal layer of serous pericardium

  The outer layer of the serous pericardium that is fused to the fibrous pericardium
• Visceral layer of serous pericardium


  The inner layer of the serous pericardium, also called the epicardium, which is one of the layers of the heart wall and adheres tightly to the surface of the heart

  
• Pericardial fluid


  The thin film of lubricating serous fluid between the parietal and visceral layers of the serous pericardium, which reduces friction as the heart moves
• Epicardium


  The thin, transparent outer layer of the heart wall composed of mesothelium, with a variable layer of delicate fibroelastic tissue and adipose tissue beneath. It imparts a smooth, slippery texture to the outermost surface of the heart and contains blood vessels, lymphatics, and vessels that supply the myocardium

  
• Myocardium


  The layer responsible for the pumping action of the heart, composed of cardiac muscle tissue. It makes up approximately 95% of the heart wall

  
• Endocardium


  The thin layer of endothelium overlying a thin layer of connective tissue, providing a smooth lining for the chambers of the heart and covering the valves. It is continuous with the endothelial lining of the large blood vessels attached to the heart

  
• Heart chambers

  The two superior receiving chambers are the atria, and the two inferior pumping chambers are the ventricles. The atria receive blood from the veins, while the ventricles eject blood into the arteries

  
• Auricles


  Wrinkled pouch-like structures on the anterior surface of each atrium, slightly increasing the capacity of the atria to hold a greater volume of blood
• Right atrium


  Forms the right surface of the heart and receives blood from the superior vena cava, inferior vena cava, and coronary sinus. It is about 2-3 mm in average thickness

  
• Tricuspid valve


  The valve between the right atrium and right ventricle, consisting of three cusps or leaflets. Also called the right atrioventricular valve
• Right ventricle


  Located below the right atrium, about 4-5 mm in average thickness and forming most of the anterior surface of the heart

  
• Interventricular septum


  The partition separating the right and left ventricles
• Pulmonary trunk and pulmonary semilunar valve

  Blood passes from the right ventricle through the pulmonary valve into the pulmonary trunk, which divides into right and left pulmonary arteries carrying blood to the lungs
• Left atrium


  About the same thickness as the right atrium, forming most of the base of the heart. It receives blood from the lungs through four pulmonary veins

  
• Bicuspid valve


  The valve between the left atrium and left ventricle, also called the mitral or left atrioventricular valve, consisting of two cusps
• Left ventricle


  The thickest chamber of the heart, averaging 10-15 mm, forming the apex of the heart

  
• Aortic valve


  The valve through which blood passes from the left ventricle into the ascending aorta
• Atrioventricular (AV) valves

  The tricuspid and bicuspid valves located between an atrium and a ventricle
• Semilunar (SL) valves

  The aortic and pulmonary valves, made up of three crescent moon-shaped cusps
• Blood flow through the heart

  1. Oxygen-poor blood from the body enters the right atrium through the superior and inferior vena cavae

  2. Blood flows from the right atrium to the right ventricle through the tricuspid valve

  3. Blood is pumped from the right ventricle through the pulmonary valve into the pulmonary arteries to the lungs

  4. Oxygen-rich blood returns from the lungs to the left atrium through the pulmonary veins

  5. Blood flows from the left atrium to the left ventricle through the mitral valve

  6. Blood is pumped from the left ventricle through the aortic valve into the aorta to be distributed throughout the body

  
• Pulmonary circulation

  1. Moves blood between the heart and the lungs

  2. The right side of the heart is the pump for pulmonary circulation

  3. It receives all of the dark-red deoxygenated blood returning from the systemic circulation