cardiovascular system

• Deoxygenated blood

  blood depleted of oxygen
• oxygenated blood

  blood loaded with oxygen
• pulmonary circuit

  circulation of blood through the pulmonary artery to the lungs as pulmonary vein back to the heart
• systemic circuit

  The circulation of blood through the aorta, to the body and vena cava, back to the heart
• Myogenic

  The capacity of the heart to generate its own electrical impulse which cause the cardiac muscles to contract
• Conduction system

  A set of structures in the cardiac muscle which create and transmit an electrical impulse forcing the atria and ventricles to contract
• What does the SA (sino - atrial) node do?

  Initiates heartbeats.
• What does the AV (atrio - ventricular) node do?

  Collects the impulses and delays the impulse slightly allowing the atria contraction to finish
• Where is the bundle of his located?

  in the septum
• How does the heart complete a full contraction?

  • SA node (pacemaker) initiates the impulse and travels through the left and right atria
  • The AV node collects the impulses and delays them slightly to allow the atria contraction to finish
  • Both atria contract and the impulse is passed into the bundle of HIS in the septum
  • The impulse travels down to the bottom of the heart via the purkyne fibers
  • Both ventricles contract
  • Once the journey is complete, the atria and ventricles relax and the heart refills with blood
• What is the definition of heart rate?

  Amount of times the heart beats per minute
• What is the average heart rate?

  70-72 BPM
• What is a persons max heart rate?

  220 - age
• What happens if a resting heart rate is below 60 BPM?

  This is labelled as bradycardia which is generally seen in trained athletes
• What is the definition of Bradycardia?

  It is a result of an increase in stroke volume due to hypertrophy that is an increase in size of muscle in the heart
• What is the definition of stroke volume?

  The volume of blood ejected from the ventricles per beat
• What is the definition of venous return?

  The return of blood back to the right atrium through the veins (vena cava)
• What is Diastole?

  Ventricular relaxation and filling
• What is systole

  Ventricular contraction and ejection
• what is the average stroke volume?

  80 - 120 ML/Beat
• What two factors is stroke volume dependent on?

  1. Venous return is the volume of blood returning to the heart. The greater the return of blood to the heart, the greater the volume of blood available for ejection.
  2. Ventricular elasticity and contractility refers to the the degree of stretch in the cardiac muscle fibers. The greater the stretch, the greater force of contraction.
• What is the definition of Cardiac Output?

  The volume of blood ejected from the heart per minute
• what is the average Cardiac Output?

  6.3 L Per minute