CS - Heart

• Heart Structure


  Epicardium

  Myocardium

  Endocardium
• Epicardium


  Outside walls - visceral pericardium
• Myocardium


  Compact with cardiac muscle tissue - contracts
• Endocardium


  Thin white layer of epithelial tissue
• Pressure Movement in heart

  High to low
• Septum


  Divides heart into left and right
• Atria


  Low pressure - receiving chambers of blood from circulation around body
• Ventricles


  Inferior chambers - discharge blood each contraction
• Arteries


  Away From body, Red in colour
• Veins


  Towards heart , Blue in colour
• Pulmonary Circulation Loop


  Right ventricle pumps blood through semi-lunar valve to the pulmonary trunk. disperses into lungs and becomes oxygenated by capillaries
• Systemic Loop


  Left Ventricle flexes, Forces blood through semilunar valve into Aaorta and throughout body. Once oxygen-depleted, enters through superior/inferior vena cava
• Systolic BP


  Peak Blood Pressure produces by contracting ventricles
• Diastolic BP


  pressure in arteries when relaxed
• Blood Vessels


  Tunica Intima

  Tunica Media

  Tunica Externa
• Tunica Intima


  Contains Endothelium
• Tunica Media


  Smooth Muscle Cells
• Tunica Externa


  Made of Collagen
• Capillary Walls


  Single epithelial wall, only tunica intima. oxygen & nutrients delivered through diffusion
• Capillary Beds


  Exchange gases, nutrients & thermoregulation
• Action Potential


  Signals along membrane of a cell called impulses
• Pacemaker Cell


  Make action potentials through contractile cells of heart - coordinated contraction
• Depolarisation


  SA Node - AV Node - AV Bundle - Purkinje Fibers
• SA Node


  impulses 75 per minute
• Purkinje Fiber


  depolarises cell in both ventricles
• AV

  Slows Impulse Down - allows fewer gap junctions giving Atria time to contract
• P Wave


  Atrial Depolarisation
• QRS Complex


  Ventricular Depolarisation
• T Wave 


  Ventricular Repolarisation
• EDV


  Volume of blood after relaxation
• ESV


  Volume of blood after contraction
• Cardiac Output


  Amount of blood pumped by each ventricle per one minute
• Stroke Volume


  Volume of blood in each ventricle after each contraction
• Parasympathetic System


  Decreases HR
• Sympathetic System


  Increases HR
• Affects on SV


  Pre-load

  Contractility

  After-Load
• Preload


  amount of ventricular stretch caused by diastolic volume. More EDV, more preload
• Contractility Force


  Force of contraction ay any EDV - Increases sympathetic creates more contractility.
• Afterload


  Aaortic Pressure in left ventricle, decreases SR