Transport Of Blood Gases Flashcards
Explain the cause of the Bohr shift AND how it increases oxygen delivery to the working muscles (3 marks)
- exercise increases temperature
- exercise causes increased acidity in blood
- ## curve shifts to the right
Describe how running affects the venous return mechanism (3marks)
- venous return increases
-heart rate increases - ## increased muscle contractions pushes blood from veins towards heart
Explain how redistribution of blood occurs during exercise (3 marks)
- increased blood acidity is detected through chemoreceptors
- message sent to the medulla
- tells the sympathetic nervous system to cause either vasodilation or vasoconstriction
- vasodilation occurs to areas needing blood
- vasoconstriction of areas not needing as much blood
Explain why blood flow to the brain remains the same during rest and maximum effort (2 marks)
Brain function is maintained during exercise so oxygen is required
Describe 2 characteristics of veins which assists the transport of blood (2 marks)
- valves
- wider lumen
- thinner muscle layer
Where is myoglobin found in the body and what is its role during exercise (2)
- found in muscles
- carries oxygen
3 characteristics or functions of arteries
- thick elastic walls
- small lumen
- smooth muscle layer
- carry blood away from the heart
What is the significance of the arterio-venous oxygen increase
- difference between oxygen content of arterial and venous blood
- more oxygen is needed
- oxygen needed for energy
- aerobic exercise so stamina needed
- leads to improved performance
- increased oxygen diffusion at lungs
- more oxygen in the blood
What factors determine blood pressure in arteries (3)
- increased blood flow / cardiac output
- sweating
- age/ fitness level
- health e.g. Diet
Explain why aerobic training improves the performers ability to transport oxygen
- more blood haemoglobin
- more oxygen extracted by muscles
- more capillaries
2 ways in which co2 is transported by the blood
- dissolved in plasma
- forms carbaminohaemoglobin
- as bicarbonate
Explain how oxygen is taken up by haemoglobin from the lungs and released at the muscle site
- forms oxyhemoglobin
- at lungs, high partial pressure of O2 but low partial pressure in blood
- haemoglobin becomes saturated
How does running assist the venous return mechanism
- muscles contract to compress veins
- veins have one way valves to prevent back flow
- change in pressure
- blood pushed towards heart
Explain how this redistribution of blood is achieved when running
- increased blood acidity
- detected by chemoreceptors
- message sent to the medulla
- vasoconstriction to organs
- vasodilation to muscles
How to work out cardiac output
Stroke volume x heart rate
