Lecture 13 - Control of Breathing during Exercise Flashcards
1
Q
what is hypernea?
A
- an increase in ventilation that is proportional to metabolic demands
- blood gases remain normal
- during moderate-to-heavy intensity exercise
2
Q
what is hyperventilation?
A
- an increase in ventilation that exceeds metabolic demands
- blood gases deviate from normal
- during intense exercise
3
Q
why does exercise impact breathing?
A
- increase muscle work causes increase metabolism (ATP)
- increased ATP causes increased oxygen uptake and carbon dioxide production
- this causes increased breathing (alveolar ventilation)
4
Q
why do we breathe during exercise?
A
- to clear CO2 (to avoid acidosis)
- to replenish O2 (to keep saturation and pressure the same)
5
Q
How do changes in PaCO2 affect the body?
A
- even small changes cause acidosis
- the body does not work well in acidotic conditions
6
Q
what is dead space?
A
- not all air participates in gas exchange ( some doesn’t reach the alveoli)
7
Q
what are the 3 mechanisms for controlling exercise hypernea?
A
- neural feed-forward
- neural feedback
- humoral feedbacl
8
Q
what is neural feed-forward? (aka central command)
A
- learned response
- we know how much to breathe from learned experience
9
Q
what is neural feedback?
A
- like a thermometer
- can sense changes in the muscles and regulate them
- change in length, chemical concentration, etc.
10
Q
what is humoral feedback?
A
- located in the arteries/circulatory system
- detects changes in H concentration
- detects metabolic by-product changes in the arteries
- regulates the detected changes
