cardiovascular drift Flashcards
what is cardiovascular drift
why does your heart rate climb during steady state
after at least 10 minutes in a warm environment
- stroke volume and arterial pressure progressively decrease
- a progressive rise in heart rate
cardiovascular drift
occurs after period of exercise –> heart rate increases–> stroke volume decrease–> fluid lost as sweat–> results in reduced plasma volume– reduced venous return–> cardiac output also increases due to more energy needed to cool the body and sweat
what is arterio - venous difference ( A - V02)
difference between oxygen content of arterial blood arriving at the muscles and the venous blood leaving the muscles
good way to see how much oxygen is delivered and used by muscle
why at rest is the A - V02 difference low
not much oxygen is required by the muscles
what happens to A-VO2 during exercise
more oxygen is needed from the blood fo the muscles so the arterio-venous difference is high
what will happen if there is in an increase in A-VO2
will affect gaseous exchange at the alveoli so more oxygen is taken in and more carbon dioxide is removed
how does training increase A-VO2 difference
trained performers can extract a greater amount of oxygen from the blood
why is a trained footballers A-VO2 difference increases during a match and why a trained footballer has a greater A-VO2 difference than an untrained one
- A-VO2 difference is the difference between oxygen content of arterial blood arriving at the muscles and the venous blood leaving the muscles
- an increase in A-VO2 results in more blood being pumped to active muscles especially slow twitch so the trained footballer needs more blood being pumped to their active muscles in order for them to have enough energy to perform
- muscle fibres better at extracting and processing oxygen as a result of increased mitochondria numbers, more oxidative enzymes and increased levels of myoglobin
- all of this is due to the oxygen demands required by the trained footballer
