L7-9 quiz

• volume of blood ejected from the heart during one heart beat is the

  stroke volume
• PQ segment of ECG trace is

  AV nodal delay
• T wave of ECG trace is

  ventricular repolarisation
• TQ interval of ECG trace is

  ventricular diastole
• QRS complex of ECG trace is

  ventricular depolarisation
• P wave of ECG trace is

  atrial depolarisation
• QT segment of ECG trace is

  ventricular systole
• stroke volume is calculated by

  end diastolic volume (EDV) - end systolic volume (ESV)
• digitalis:

  • is a potent inhibitor of the sodium-potassium pump
  • leads to accumulation of intracellular calcium ions in heart muscle
  • is a natural product produced by the foxglove plant
  • stimulates increased contractility of the heart muscle
• nitro glycerine is used to treat angina by


  acting as a prodrug and being converted to nitric oxide
• the heart is made up of specilised cardiac muscle tissue which sets its own rhythm, is described as being myogenic
• advantages for organism living in water:

  • good buoyancy and support for external respiratory structures
  • no need to conserve water
  • counter-current system can be used to maximise the exchange of oxygen
• congestive heart failure is a condition where the heart is unable to pump blood around the body
• congestive heart failure :

  • decreases pumping pressure to systemic circulation
  • results in pulmonary oedema (swelling)
  • can result in swelling of legs and ankles
  • can be treated with digitalis
• pulse pressure can be calculated by:

  systolic blood pressure - diastolic blood pressure
• path of blood flow starting at the vena cava:

  • right atrium
  • tricuspid valve
  • right ventricle
  • pulmonary valve
  • pulmonary arteries
  • pulmonary veins
  • left atrium
  • bicuspid valve
  • left ventricle
  • aortic valve
  • aorta
• cardiac cycle:

  • passive ventricular filling
  • atrial contraction
  • atrioventricular valves close
  • isovolumetric contraction
  • semilunar valves open
  • ventricular ejection