Which blood vessel does systemic arterial blood come from?
The aorta
What type of receptors monitor oxygen tension?
Carotid bodies
What type of receptors monitor carbon dioxide tension?
Medullary CSF receptors
How does exercise affect oxygen consumption/carbon dioxide production?
It increases oxygen consumption and increases carbon dioxide production
True or false: during light exercise there is not much change in arterial oxygen and carbon dioxide tensions?
True: there is not any change in blood gas variables until you start getting into heavy exercise
What are the main triggers for the variations in gas blood variables?
Anaerobic respiration i.e. the production of H+ ions and lactate
With regards to minute expired volume (VE) what happens at the start of exercise?
At the start of exercise there is a sharp increase in minute expired volume
What part of the body is responsible for this sharp rise in VE at the start of exercise?
The CNS - the brain and higher centres drive the respiratory centre in the medulla to increase respiratory and heart rate. This is an anticipatory event.
What is the term used to describe the anticipatory event caused by the CNS?
"Central command"
What mechanisms control the gradual upward adjustment of VE during exercise?
Homeostatic mechanisms
While oxygen demand outstrips supply the body goes into ...?
oxygen debt
What type of respiration occurs during oxygen debt?
Anaerobic respiration
Why is there still a period of increased ventilation rate after exercise?
This is the period where the oxygen debt is being repaid. During this process oxygen is being consumed to reverse the metabolic processes that were occurring anaerobically and yielding anaerobic byproducts.
True or false: the 'repayment period' precisely matches the oxygen debt incurred by exercise?
True
True or false: you can repay the oxygen debt during exercise?
False - you cannot pay back the oxygen debt until you stop exercising