How is breathing rate regulated by the body to meet the increasing demands of exercise?

The command word is ‘how’ and so the question is asking by what means the body meets the increasing demands of exercise.As we all know, breathing rate increases when the body exercises, and so your answer should address the ways in which an increased breathing rate is achieved.Firstly, an increase in carbon dioxide levels in blood occurs once you begin exercising.This in turn causes an increase in blood acidity – remember, on the pH scale, the more acidic a substance is the lower its numeric value; if you refer to the pH do not write ‘an increase in pH value’ as this is incorrect (it implies the blood is becoming more alkaline).This change is detected by chemoreceptors, sensory receptors that detect certain chemical stimuli in the body’s environment – in this case an increase in blood acidity.A small cluster of chemoreceptors operates in the aortic arch (part of the upper heart) and so this is where the changes are detected.Chemoreceptors then send a nervous impulse to the Respiratory Control Centre (RCC), located in the medulla oblongata – positioned at the base of the brain.After receiving this information, the RCC sends nervous impulses to the intercostal muscles (muscles involved in the mechanical aspect of breathing).This occurs via the phrenic nerve, which is located in the neck and plays an important role in breathing control.Finally, once these impulses reach the intercostal muscles, the muscles are stimulated to perform deeper and faster breathing – remember to include both ‘deeper’ and ‘faster’, as the muscles causes both, not just one.And this is how breathing rate is regulated by the body to meet the increasing demands of exercise!Although not relevant to the question, it is also worth noting that the reverse occurs when exercise stops. Chemoreceptors detect a decrease in bloody acidity, which results in the muscles being stimulated to perform shallower and slower breathing.