heart

• what muscle is the heart made out of?

  cardiac
• cardiac muscle is myogenic meaning it automatically contracts and relaxed without fatigue
• what supplies the cardiac muscle with oxygenated blood?

  Coronary arteries
• the left ventricle has a thicker muscular wall so that it can contract with more force and pump the blood at higher pressure
• the right ventricle has thinner muscle because it pumps blood to the lungs which are closer and requires blood to flow slowly to allow time for gas exchange and so it doesn't damage the capillaries
• why does the atria have thinner muscular walls than ventricles?

  dont need to contract as much
• three stages of cardiac cycle?

  Atrial systole, ventricular systole, diastole
• how many heartbeats are required to pass the cardiac cycle once?

  1
• diastole?

  atria and ventricle relax, blood enters atria via vena cava and pulmonary vein, pressure in atria increases
• atrial systole?

  the SAN sends a wave of depolarisation through the atria causing to contract, increasing pressure, AV valves forced open, blood enters ventricles, ventricles are relaxed
• what is the long name of AV valves?

  Atrioventricular valves
• SAN stand for?

  sino-atrial node
• AVN stand for?

  atrio-ventricular node
• where is the SAN found?

  upper left wall of right atrium
• what do SAN and AVN do?

  send electrical impulses to coordinate heart muscle contractions
• ventricular systole?

  the AVN receives the wave of depolarisation from the SAN and sends a wave of depolarisation down the bundle of His into the purkyne tissues. After this short delay, the ventricles contract, increasing pressure causing AV valves to close and semi-lunar valves to open. Blood forced out of the ventricles into the pulmonary artery and aorta
• cardiac output?

  volume of blood which leaves one ventricle in one minute
• cardiac output calculation?

  Stroke volume * heart rate
• stroke volume?

  volume of blood that leaves the heart with each beat dm3
• the pacemaker is aka the SAN
• where is the sinoatrial node located?

  Right atrium
• where is the bundle of His?

  septum
• where is the atrioventricular node located?

  border of right and left ventricle but still in atria
• where are the purkyne fibres located?

  walls of ventricles
• diastole is when repolarisation occurs
• ECG = electrocardiogram
• what does ECG measure?

  waves of depolarisation
• the sound of a heartbeat is the sound of valves closing
• what happens at P wave?

  Atrial depolarisation (leads to atrial systole)
• what happens at QRS wave?

  ventricular depolarisation (leads to ventricular systole)
• what happens at T wave?

  repolarisation (leads to diastole)
• what are the waves of an ECG?

  P, QRS, T
• tachycardia?

  resting heat beat over 100bpm
• bradycardia?

  resting heart rate below 60 bpm
• atrial fibrillation?

  irregular rhythm of heart
• ectopic heartbeat?

  extra heartbeats that are out of rhythm
• c?

  c