Cardiovascular

• Anatomy


  The study of the structure and parts of living organisms
• Physiology


  The study of the functions and activities of living organisms and their parts
• Major systems of the body

  • Organs they contain
  • Functions of those systems
• Cardiovascular system


  Consists of the heart and thousands of miles of blood vessels
• Heart


  The muscular pump that forces the blood through a system of vessels made of arteries, veins, and capillaries
• Blood vessels


  • Transport blood, which carries oxygen, nutrients, hormones, enzymes, and cellular waste to and from the trillions of cells that make up our bodies
• Cells


  • Need oxygen and nutrients from digested food to make the chemical energy (ATP) that allows the cells to function properly
• Enzymes


  • Assist in the chemical reactions inside the cells
• Cardiovascular system


  • Transports waste products from chemical reactions to sites like the lungs and kidneys for excretion from the body
• Cardiac muscle


  • Provides the force to transport the blood
• Heart beat


  About 72 times a minute
• Heart


  • Can contract, rest, and immediately contract again during our entire lifetime
• Cardiovascular system


  • Has a series of valves that prevent blood from back flowing through the blood vessels
• Heart


  Helps keep us alive and healthy
• Heart


  • Positioned obliquely between the lungs in the mediastinum, about two-thirds of its bulk lies to the left side of the midline of the body, shaped like a blunt cone, about the size of a closed fist, approximately 12 cm long, 9 cm wide at its broadest point and 6 cm thick
• Layers of the heart wall

  • Epicardium (outer protective layer)
  • Myocardium (muscular middle layer)
  • Endocardium (inner layer)
• Pericardium


  Fluid-filled sac that surrounds and protects the heart
• Layers of the pericardial sac

  • Fibrous pericardium (outermost layer)
  • Serous pericardium (innermost layer)
• Pericardial cavity


  Space between the epicardium and serous pericardium, contains pericardial fluid to reduce friction and erosion
• Pericarditis


  Inflammation of the innermost layer of the pericardial sac
• Myocardium


  Layer of cardiac muscle tissue responsible for contraction of the heart
• Endocardium


  Thin layer of endothelium that lines the myocardium and covers the heart valves
• Chambers of the heart

  • Right atrium
  • Left atrium
  • Right ventricle
  • Left ventricle
• Great vessels of the heart

  • Superior vena cava
  • Inferior vena cava
  • Coronary sinus
  • Pulmonary trunk
  • Right pulmonary artery
  • Left pulmonary artery
  • Pulmonary veins
  • Ascending aorta
  • Coronary arteries
  • Arch of the aorta
  • Descending thoracic aorta
  • Abdominal aorta
• Heart valves


  • Tricuspid valve
  • Bicuspid/mitral valve
  • Pulmonary semilunar valve
  • Aortic semilunar valve
• Blood flow through the heart

  1. Deoxygenated blood returns to right atrium via superior and inferior venae cavae

  2. Blood squeezed through tricuspid valve into right ventricle

  3. Blood pumped through pulmonary semilunar valve to pulmonary trunk and lungs

  4. Oxygenated blood returns to left atrium via pulmonary veins

  5. Blood squeezed into left ventricle

  6. Blood pumped through aortic semilunar valve to ascending aorta and body
• Tricuspid valve


  Found between the right atrium and the right ventricle, made of three cusps or flaps
• Bicuspid or mitral valve


  Found between the left atrium and the left ventricle, made of two cusps or flaps
• Valves of the heart

  • Tricuspid valve
  • Bicuspid or mitral valve
  • Pulmonary semilunar valve
  • Aortic semilunar valve
• Pulmonary semilunar valve


  Found in the right ventricle where the pulmonary trunk exits the heart, made of three cusps or flaps
• Aortic semilunar valve


  Found in the left ventricle where the ascending aorta leaves the heart, made of three cusps or flaps
• Blood flow through the heart

  1. Deoxygenated blood returns to the right atrium via superior and inferior venae cavae

  2. Blood is squeezed through the tricuspid valve into the right ventricle

  3. Blood is pumped through the pulmonary semilunar valve to the pulmonary trunk

  4. Oxygenated blood returns to the left atrium through four pulmonary veins

  5. Blood is squeezed through the bicuspid or mitral valve into the left ventricle

  6. Left ventricle pumps blood through the aortic semilunar valve to the ascending aorta
• Sinoatrial (SA) node


  Also known as the pacemaker, initiates each cardiac cycle, found in the superior wall of the right atrium
• Atrioventricular (AV) node


  In the lower part of the right atrium, sends electrical impulses through the atrioventricular bundle or bundle of His to the top of the interventricular septum
• Conduction system of the heart

  1. SA node initiates each cardiac cycle and spreads electrical impulses over both atria

  2. AV node sends electrical impulses through the bundle of His

  3. Bundle of His distributes the electrical impulses over the medial surface of the ventricles

  4. Purkinje's fibers distribute the impulses to the cells of the myocardium of the ventricle causing actual contraction
• Cardiac cycle


  • Atria contract simultaneously while ventricles relax, ventricles contract simultaneously while atria relax
  • Contraction is called systole, relaxation is called diastole
  • Average cardiac cycle takes 0.8 second
• Layers of artery and vein walls

  • Tunica intima (innermost, made of endothelial cells)
  • Tunica media (middle, made of smooth muscle)
  • Tunica adventitia (outer, made of white fibrous connective tissue)
• Lumen


  Cavity of blood vessels
• Arteries


  • Thicker and stronger than veins, elastic and can contract
• Arterioles


  Small arteries that deliver blood to capillaries