cardiac volumes

• Heart


  Muscular pump that sits behind the sternum inside the thoracic cavity
• Aortic arch


  Main artery leaving the left ventricle, carries blood through the systemic circuit to working muscles during exercise
• Cutting the aorta


  Blood departing the aorta
• Stroke volume


  Volume of blood leaving the left ventricle per contraction
• Heart rate


  Number of times the heart beats per minute
• Typical resting stroke volume is around 70 millilitres
• Typical resting heart rate is around 70 beats per minute
• Cardiac output


  Volume of blood leaving the left ventricle per minute
• Cardiac output is measured in litres per minute
• Stroke volume is measured in litres or millilitres
• Heart rate is measured in beats per minute
• Resting cardiac output is around 5 litres per minute
• Sub-maximal exercise


  Non-maximal exercise, e.g. marathon running, 30-minute cycling
• During sub-maximal exercise, stroke volume may increase to around 100 millilitres and heart rate may increase to around 150 beats per minute
• During sub-maximal exercise, cardiac output may increase to around 15 litres per minute
• During maximal exercise, stroke volume may increase to around 140 millilitres and heart rate may increase to around 200 beats per minute
• Heart operates by the all-or-none law


  Heart beats maximally or not at all
• Heart rate is controlled through neural, hormonal, and intrinsic factors
• Left Atrium


  Upper chamber of the heart that receives oxygenated blood from the lungs via the pulmonary veins
• Left Ventricle


  Lower chamber of the heart that pumps oxygenated blood to the rest of the body through the aorta
• Cardiac Output


  Volume of blood leaving the left ventricle per minute