HEART AND PERIPHERAL

• Cardiovascular system


  Also known as Circulatory System, an organ system that permits blood to circulate and transport nutrients, oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body. It provides nourishment, helps in fighting diseases, stabilizes temperature and pH, and maintains homeostasis.
• Components of the cardiovascular system

  • Heart
  • Blood vessels
  • About 5 liters of blood
• Heart


  A muscular pump that forces blood through a system of vessels made of arteries, veins and capillaries
• Heart


  • Broad, flat base about 9 cm wide and directed toward the right shoulder, extending vertically from the left second and fifth intercostal space and horizontally from the right edge of the sternum to the left midclavicular line. Its apex points inferiorly toward the left hip.
• Mediastinum


  The central compartment of the thoracic cavity surrounded by loose connective tissue, as region that contains a group of structures within the thorax.
• Precordium


  The part of the front of the chest wall that overlays the heart and the epigastrium.
• Pericardial cavity


  Formed by the Pericardium, which surrounds the heart and anchors it within the mediastinum.
• Layers of the pericardium

  • Fibrous pericardium
  • Serous pericardium
• Fibrous pericardium


  Layer of connective tissue that provides support and protection for the heart, with attachments to the diaphragm, the sternum, and the vertebral column. It holds the heart in place.
• Serous pericardium

  Contains the pericardial fluid. It has two layers: the parietal pericardium that lines the fibrous pericardium, and the visceral pericardium (epicardium) that lines the surface of the heart.
• Layers of the heart

  • Epicardium (visceral pericardium)
  • Myocardium
  • Endocardium
• Myocardium


  Cardiac muscles responsible for the contraction of the chambers.
• Endocardium


  Lines the inner surface of the heart which allows blood to move easily through the heart.
• Chambers of the heart

  • Right Atrium
  • Right Ventricle
  • Left Atrium
  • Left Ventricle
• Heart valves

  • Atrioventricular Valve (Tricuspid Valve, Bicuspid/Mitral Valve)
  • Semilunar Valves (Pulmonic, Aortic)
• Chordae Tendinae


  Tendon-resembling fibrous cords of connective tissue that connect the papillary muscles to the tricuspid valve and the bicuspid valve in the heart.
• Coronary system


  Circulation of blood that supply oxygen to the myocardium, including coronary arteries and coronary veins.
• Sequence of systemic blood circulation

  Not provided
• Heart conduction system


  Special electrical cells that generate and coordinate electrical impulses to the myocardial cells, including properties like rhythmicity, automaticity, conductivity, contractility, and excitability.
• Components of the heart conduction system

  • Sinoatrial Node (SA Node)
  • Atrioventricular Node (AV Node)
  • Bundle of His/Atrioventricular Bundle
  • Left and Right Bundle Branches
  • Purkinje Fibers
• Arrhythmias

  • Not provided
• Electrocardiogram (ECG/EKG)


  Procedure that measures electrical signals in the heart. It can show if the heart is beating at a normal rate and strength, and help determine the size and position of the heart's chambers.
• Normal heart beat

  60-100 beats per minute
• Normal heart sounds

  • Lubb (S1)
  • Dubb (S2)
• Lubb (S1)


  Lower in pitch, occurs at the beginning of ventricular systole and results from closure of AV valves.
• Dubb (S2)


  Occurs at the beginning of ventricular diastole and results from closure of the semilunar valves.
• Cardiac cycle


  The filling and emptying of heart chambers, with two phases: diastole (filling, relaxation of ventricles) and systole (emptying, contraction of ventricles).
• Phases of the cardiac cycle

  • Atrial Systole
  • Ventricular Systole
  • Atrial Diastole
  • Ventricular Diastole
• Cardiac output

  Volume of blood pumped by either ventricle per minute, calculated as stroke volume (volume of blood pumped per ventricle each time the heart contracts) multiplied by heart rate.
• Points of auscultation

  • Aortic Area
  • Pulmonic Area
  • Erb's Point
  • Mitral (Apical) Area
  • Tricuspid Area
• S1 (Lubb)


  Occurs at the beginning of ventricular systole and results from closure of AV valves. A normal heart sound.
• S2 (Dubb)


  Occurs at the beginning of ventricular diastole and results from closure of the semilunar valves. A normal heart sound.
• S3 (Ventricular gallop)


  Occurs just after S2 when the mitral valve opens, allowing passive filling of the left ventricle. Can be a normal finding in children, pregnant females and well-trained athletes, but can also be a sign of heart failure.
• S4 (Atrial gallop)


  Occurs during active LV filling when atrial contraction forces blood into a noncompliant LV. Always an abnormal finding, can be a sign of heart failure or left ventricular hypertrophy.
• Blood vessels

  • Tubular structures carrying blood, with layers including tunica adventitia/externa, tunica media, and tunica intima. Capable of vasoconstriction and vasodilation.
• Artery

  Carries oxygenated blood away from the heart, classified as elastic arteries, muscular arteries, and arterioles.
• Capillary


  Extremely small blood vessel located within the body tissues, where gases, nutrients, and fluids are exchanged.
• Capillary exchange


  Most exchange across the capillary wall occurs by diffusion, affected by blood pressure, capillary permeability and osmosis. Fluid gained by the tissues is removed by the lymphatic system.
• Vein


  Carries deoxygenated blood back to the heart. Veins with more than 2mm diameter contain valves to prevent backflow.
• Types of veins

  • Large veins
  • Small veins
  • Venules