# Determining Lung Capacity

Topics: Respiratory physiology, Lung volumes, Lung Pages: 5 (803 words) Published: May 12, 2010
Determining lung capacity

Experiment:

This is the experiment of determining lung capacity. All the students in the group measured three types of different parameters: vital capacity, expiratory reserve and tidal volume. “Lung volumeizing refer to physical differences in lung volume, while lung capacities represent different combinations of lung volumes, usually in relation to inhalation and exhalation.The average pair of human lungs can hold about 6 liters of air, but only a small amount of this capacity is used during normal breathing. Several factors affect lung volumes, some that can be controlled and some that can not. Lung volumes can be measured using the following terms[1]:

Table 1

|Larger volumes |Smaller volumes | |males |Females | |taller people |shorter people | |non-smokers |smokers | |athletes |non-athletes | |people living at high altitudes |people living at low altitudes |

The results that were measured during the experiment are showen in the table.

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1. Vital capacity is the amount of air that can be forced out of the lungs after maximal inspiration. The precise formula for measuring vital capacity is: Inspiratory reserve volume( IRV) + Tidal volume( TV) + Expiratory reserve volume (ERV).[2] My calculations showed next values of diameter of the balloon: First measurement = 19 cm

Second measurement = 20 cm
Third measurement = 21 cm
Fourth measurement = 21 cm

Average one is = 20. 25
However, the only formula that we used in this experiment to calculate the volume in balloon is next one: VOLUME = 1.33 [pic] r[pic], where r = [pic] of the average diameter of the balloon and [pic]= 3.14.

So in this case, vital capacity is:
r = 10.125
V= 1.33 [pic] 3.14 [pic]( 10.125)[pic]
V= 4334.77

2. Expiratory reserve capacity is the amount of additional air that can be breathed out after the end expiratory level of normal breathing.[3] Expiratory reserve that was measured showed next values:

First measurement =13.5 cm
Second measurement = 14 cm
Third measurement = 13.5 cm
Fourth measurement = 14 cm

Average one is = 13.75
r = 6.875
V = 1.33 [pic] 3.14 [pic]( 6.875)[pic]
V = 1357.06
3. Tidal volume is the amount of air breathed in or out during normal respiration[4]. Tidal volume that was measured showe next results:
First measurement = 15 cm
Second measurement = 15.5 cm
Third measurement = 15.5 cm
Fourth measurement = 15 cm...