cardio

• Cardiovascular system


  Simply called the "blood-vascular" or Circulatory System

  
• Components of the cardiovascular system

  • Blood
  • Heart
  • Blood vessels

  
• Blood


  Fluid that transports nutrients, and wastes products to and from the cell, circulated by the heart

  
• Heart


  Muscular pumping device
• Blood vessels


  Closed system, including arteries, veins and capillaries
• Blood contained in the circulatory system is pumped by the heart around a close circuit of vessels as it passes again and again to various circulation of the body

  
• Heartbeats: 100,000 per day, 35,000,000 per year, 2,500,000,000 in a lifetime
• The left side of the heart pumps blood through an estimated 100,000 kilometers or 60,000 miles of blood vessels

  
• The right side of the heart pumps through the lungs enabling blood to pick up oxygen and unload carbon dioxide
• While sleeping, the 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
• At this rate, the heart pumps 14,000 liters of blood per day and 5,000,000 liters per year

  
• Heart pumps more vigorously when you are active. Thus the actual blood volume the heart pumps is much larger in a single day

  
• 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

  
• Cardiologist


  Physicians who specialize in the field of cardiology, a specialty of internal medicine
• Size, form, location of the 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
  • Lies in the mediastinum, an anatomical region that extends from the sternum to the vertebral column, from the first rib to the diaphragm, and between the lungs
  • 2/3 of the mass of the heart lies to the left of the body's midline

  
• Apex


  Pointed, formed by the tip of the left ventricle, directed anteriorly, inferiorly, and to the left
• Base


  Opposite the apex and is its posterior aspect, formed by the atria, mostly the left atrium
• Functions of the heart

  • Generating blood pressure
  • Routing blood
  • Ensuring one way blood flow
  • Regulating blood supply

  
• Pericardium


  Membrane that surrounds and protects the heart, confines the heart to its position (mediastinum) while allowing sufficient freedom of movement for vigorous and rapid contraction

  
• Parts of the pericardium

  • Fibrous pericardium
  • Serous pericardium

  
• Fibrous pericardium


  Composed of tough, inelastic, dense irregular connective tissue, resembles a bag that attaches to the diaphragm, fused to the connective tissue of the blood vessels entering and leaving the heart, prevents overstretching of the heart, provides protection, and anchors the heart in the mediastinum

  
• Serous pericardium


  Thinner, more delicate membrane that forms a double layer around the heart, including the parietal layer (outer) and the visceral layer (epicardium, inner)

  
• Pericardial fluid


  Thin film of lubricating serous fluid between the parietal and visceral layers, reduces friction between the layers of the serous pericardium as the heart moves

  
• Epicardium


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

  
• Myocardium


  Responsible for the pumping action of the heart, composed of cardiac muscle tissue, 95% of the heart wall, muscle fiber cells wrapped and bundled with connective tissue sheets

  
• Endocardium


  Thin layer of endothelium overlying a thin layer of connective tissue, provides a smooth lining for the chambers of the heart and covers the valves of the heart, continuous with the endothelial lining of the large blood vessels attached to the heart

  
• Four chambers of the heart

  • Atria (two superior receiving chambers)
  • Ventricles (two inferior pumping chambers)
• Auricle


  Wrinkled pouch-like structure on the anterior surface of each atrium, slightly increases the capacity of an Atrium so that it can hold a greater volume of blood
• Veins


  Blood vessels carrying blood TOWARDS the heart

  
• Arteries


  Blood vessels carrying blood AWAY from the heart

  
• Tricuspid valve


  Valve between the right atrium and right ventricle, consists of three cusps or leaflets, also called the right atrioventricular valve
• Right ventricle


  Can be found below the right atrium, about 4–5 mm (0.16–0.2 in.) in average thickness, forms most of the anterior surface of the heart, separated from the left ventricle by the interventricular septum
• Pulmonary valve


  Valve between the right ventricle and pulmonary trunk, also called the pulmonary semilunar valve
• Left atrium


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

  
• Bicuspid/mitral/left atrioventricular valve


  Valve between the left atrium and left ventricle, has two cusps
• Left ventricle


  The thickest chamber of the heart, averaging 10–15 mm (0.4–0.6 in.) and forms the apex of the heart

  
• Aortic valve


  Valve between the left ventricle and ascending aorta, also called the aortic semilunar valve
• Tricuspid and bicuspid valves

  Atrioventricular (AV) valves, located between an atrium and a ventricle
• Aortic and pulmonary valves


  Semilunar (SL) valves, made up of three crescent moon–shaped cusps
• Pathway of blood flow through the heart

  1. Oxygen-poor blood from body returns to right atrium

  2. Blood from upper body returns through superior vena cava, blood from lower body returns through inferior vena cava

  3. Right atrium contracts, tricuspid valve opens, blood pumped into right ventricle

  4. Tricuspid valve closes, right ventricle contracts, pulmonary valve opens, blood pumped into pulmonary artery to lungs

  5. Oxygen-rich blood from lungs returns to left atrium

  6. Left atrium contracts, mitral valve opens, blood pumped into left ventricle

  7. Mitral valve closes, aortic valve opens, left ventricle contracts, oxygen-rich blood pumped into aorta

  8. Aortic valve closes, atria fill with blood, cycle repeats