Respiratory Adjustments during Exercise (Nursing)

00:01 So how do we adjust when we are undergoing exercise and other things.

00:08 So a lot of what we've talked about on this topic has referred to respiration at rest, but what happens during exercise? So during exercise, adjustments are going to be geared both toward the intensity as well as the duration of the exercise.

00:28 Hypercapnia is an increase ventilation and response to our metabolic needs.

00:35 So as our metabolic needs increase our ventilation can increase up to 20 fold.

00:44 The ventilation increase happens in kind of a stepwise manner where first it increases abruptly and then it's a more gradual increase and then it reaches a steady state where it pretty much plateaus.

00:59 Once we stop exercising, again, we have a very abrupt decline in our ventilation followed by a more gradual decrease in ventilation.

01:10 Interestingly during exercise our partial pressures of carbon dioxide and oxygen as well as our pH remain pretty constant because our body has all of these compensatory mechanisms that allow for us to not really change these levels even though we're going from rest to something really intense that involves a lot more metabolism or metabolic activity.

01:39 Abrupt increases in ventilation at occurs as exercise begins involves three neural factors.

01:46 First, you have the psychological stimuli.

01:49 So your body is anticipating that you're about to exercise and that may actually get you to start breathing a little faster.

01:57 So right before a race you actually start to increase your ventilation.

02:02 Also simultaneous cortical motor activation of your skeletal muscles and your respiratory centers also occurs.

02:10 So as our skeletal muscles are being stimulated or activated, our respiratory centers are also being stimulated and activate in.

02:20 Also, we have excitatory impulses to these respiratory centers from proprioceptors and are moving muscles or call proprioceptors help our body understand our orientation with space.

02:34 And so these proprioceptors are found in our tendons and joints and these are all going to send messages to the respiratory centers saying hey, the body is moving we need to respond.

02:48 After this abrupt increase we have a more gradual increase until we eventually plateau.

02:54 And this is caused because of the increased rate of carbon dioxide that is now being delivered to the lungs.

03:02 So now we have more carbon dioxide being delivered to a lungs because we have more metabolic activity and because of that we actually need to get rid of this carbon dioxide.

03:15 So we need to go through respiration a little bit more but we start to just kind of plateau at a certain point.

03:25 So ventilation is going to decline suddenly when we stop exercising.

03:31 So let's say we've got to the end of the race, now we're going to stop breathing extremely fast.

03:37 And this happens because three neural factors are shut off.

03:42 Then from there, we have the gradual decline to the baseline and this is due to the fact that we're now starting to decline the carbon dioxide flow from the tissues into our blood.

03:57 Sometimes exercise can lead to anaerobic respiration and the formation of lactic acid.

04:04 This happens because of a lack of oxygen in the muscles, but this lack of oxygen is not because we're not breathing enough, but rather it is because of inefficient cardiac output as well as the fact that our skeletal muscles and all of the metabolic activity that is occurring in these skeletal muscles just cannot keep up with the amount of oxygen that we're taking in during these exercises.