in the previous video we talked about lung volumes and capacities today we're going to take a closer look at them as we mentioned previously lung volumes and capacity is measured by spirometry the first thing that we're going to take a look at is called the TLC or the total lung capacity total lung capacity is the amount of gas in the lungs after a maximal inspiration so if you take a deep breath in and hold it the volume of gas in your lungs is the total lung capacity normally it's six liters for adult males and 4.2 liters for adult females next we're going to take a look at vital capacity or VC vital capacity is the amount of gas that can be exhaled after a maximal inspiration so what you do is take a deep breath all the way in and then blow it all the way out and that would be your vital capacity the residual volume is the amount of gas remaining in the lungs after a maximal expiration so as you're sitting there and you blow all the way out as far as you can the amount of gas that remains in the lungs is the residual volume normally it makes up 20% of the total lung capacity vital capacity plus residual volume equals total lung capacity tidal volume is the amount of gas an individual inspires or expires during normal quiet breathing so as you sit there breathing normally in and out that's your tidal volume it is seven to eight percent of the total lung capacity the inspiratory reserve volume is the amount of gas that an individual can inhale above a tidal inspiration so as you're sitting there and you make a normal tidal inspiration and then take a deep breath all the way in as far as you can that's your in fitori reserved volume normally it's 60% of the total lung capacity the expiratory reserve volume is the amount of gas that an individual can exhale beyond a title expiration so as you're sitting there and exhale normally and then push all the gas out that you possibly can that's your expert or e-reserve volume normally it's 20% of total lung capacity tidal volume plus inspiratory reserve volume plus expert ory reserve volume equals vital capacity FRC or the functional residual capacity is the amount of gas remaining in the lungs after a title expiration normally it is 40% of the total lung capacity there are three different types of capacities the first is the lung capacities it includes inspiratory capacity which we're going to discuss next the functional residual capacity vital capacity and total lung capacity the inspiratory capacity is the amount of gas that an individual can inhale starting at a title expiration so as you breathe out normally and then take a deep breath all the way in that's the inspiratory capacity therefore it includes the tidal volume and the inspiratory reserve volume for instance it would be smart to take an inspiratory capacity before jumping in water so that you can stay underwater longer normally it is 60% of the total lung capacity and finally going back to the functional residual capacity this cannot be measured directly with spirometry because the residual volume or RV cannot be exhaled the functional residual volume is measured indirectly using helium dilution or nitrogen washout the functional residual volume includes expert ory reserve and the residual volume thank you for tuning into biology made simple please don't forget to subscribe like and comment [Music]