Oxygen dissociation Curve and re distribution of blood Flashcards
What does the Oxygen dissociation curve help us to understand?
How haemoglobin in our blood transports and relaeses oxygen.
Where is the blood fully saturated with oxygen
At the lungs
What percentage of Oxygen is given up to the muscles?
23%
Why does the oxygen dissociation curve shift to the right during exercise?
It shifts to the right when more oxygen is required by the muscle tissues. The oxygen dissociates more readily. It is called the BOHR SHIFT
What are the 3 factors that cause the Bohr shift to occur?
1)Increase in Blood Temperature2)Increase in Partial Pressure of Carbon Dioxide3)PH decreases because more co2 will lower the PHAll 3 factors cause the oxygen to dissociate faster and more readily.
What is the vascular shunt mechanism?
The redistribution of cardiac output.
Where is the blood redistributed from during exercise and why?
Distributed from the intestine and kidneys to the muscle tissue to meet the increase demand for oxygen
Why should a performer not eat within 2 hours of competing?
A full gut would result in more blood being directed to the stomach instead of the working muscle and this would have a detrimental effect on performance.
Why does the blood flow to the brain remain constant?
To ensure the brain function is maintained as the brain needs oxygen for energy.
What controls the both the blood pressure and the blood flow?
Vasomotor centre in the medulla oblongata of the Brain
What is vasodilation
The widening of the blood vessels to increase the flow of blood to the capillaries
What is vasoconstriction
The narrowing of the blood vessels to reduce blood flow into the capillaries.
How is blood re-distributed during exercise?
Chemical changes, such as an increase in carbon dioxide and lactic acid, are detected by chemoreceptors this causes the vasomotor centre to redistribute the blood through vasodilation and vasoconstriction. During exercise Blood is needed at the working muscles so the capillaries vasodilate (widen) to allow more blood to flow into the arterial capillaries , supplying the muscles with oxygen and vasoconstriction will occur in the arterioles supplying the non essential organs (ntestine and kidneys)
What is the function of pre capillary sphincters?
Tiny rings of muscles located at the opening of capillaries. When they contract blood flow is constricted through the capillaries and when they relax blood flow is increased.
Why is re-distribution of blood important?
1)Increase the supply of oxygen to the working muscles.2)Remove waste products from the muscles, such as carbon dioxide and lactic acid.3)Ensure more blood goes to the skin during exercise to regulate body temperature and get rid of heat through radiation, evaporation and sweating.4)Blood flow to the brain remains constant as it needs oxygen for energy and to maintain function.
