Respiration During Exercise Part 2 Flashcards
The ventilatory response to constant load steady state exercise occurs in 3 phases:
- Immediate increase in Ve
2.exponential increase in Ve - Plateau
What is ventilatory threshold
When ventilation increases linearly with exercise.
Where does exercise induced arterial hypoxaemia occur
Occurs in highly trained male during heavy exercise and the majority of females regardless of fitness or exercise intensity
What is total work the sum of
Sum of elastic, flow resistive and inertial forces
What is oesophageal pressure
Is an estimate of pleural pressure and can be used to calculate the mechanical work of breathing during exercise
Where are the respiratory central pattern generators located
Pons and medulla
What are the 3 main groups of neurons
1.ventral respiratory group (inspiration and expiratory)
2. Dorsal respiratory group (inspiration)
3.pontine respiratory group (modulatory)
Location and function of chemoreceptors :
Located at the aortic arch and cartoid body.
Detects changes in po2 of blood perusing systemic and cerebral circulation
What do peripheral chemoreceptors relay
Sensory info to the medulla
What other stimuli activate peripheral chemoreceptors
Temp, adrenaline and co2
Central chemorespectors location:
Located in the ventral surface of the medulla.
Chemoreceptor feedback:
- Chemoreceptor detect error signals
2.central and peripheral ones increase afferent input to the brainstem in response to increasing paco2 of decreasing ph
3.predator neurons in the dorsal respiratory group are activated
4.inspiratory muscle contraction, increasing Ve
Do the lungs adapt to exercise training
With few exceptions, the lungs and airways do not adapt to physical training.
5 examples of how the pulmonary system may limit exercise performance:
- EIAH
2.exercise induced laryngeal obstruction
3.expiratory flow limitation
4.respiratory muscle fatigue - Intrathoracic pressure effects on cardiac output
