EduNinja• Describe the differences in composition between inspired and expired air, limited to: oxygen, carbon dioxide and water vapour
Fig. 1.1 shows two photomicrographs of a cross-section of trachea.
Fig. 1.1
The open space at the centre of the trachea is labelled A in Fig. 1.1.
Air travels into and out of the trachea through this open space.
State a gas that is at a higher concentration in expired air than in inspired air.
Table 1.1 compares the composition of inspired and expired air.
Table 1.1
Complete Table 1.1 by writing the names of gases B, C and D.
The concentration of atmospheric carbon dioxide has increased considerably in recent years.
When the scientists were working in the plot with a carbon dioxide concentration of 550 ppm , their breathing rates were higher than when they worked in the other plot.
Suggest why their breathing rates were higher.
Complete Table 3.1 by writing in the percentages of carbon dioxide and oxygen in inspired air and in expired air.
Table 3.1
A study estimated the number of people with chronic obstructive pulmonary disease (COPD) in India. Data were collected from two groups of people, those who lived in cities and those who lived in villages.
Fig. 2.1 shows the results.
State two ways in which the composition of inspired air differs from the composition of expired air.
1
2
What are the approximate percentages of oxygen and carbon dioxide in atmospheric air?
oxygen / %
carbon dioxide
/ %
16
4.00
16
8.00
20
0.04
20
4.00
Which row shows the approximate percentage of gases in expired air?
percentage of
carbon dioxide
percentage of
oxygen
12
9
4
16
24
24
27
20
What is the approximate percentage of oxygen contained in the air breathed out of the lungs?
0\%
4\%
16\%
20\%
The diagram shows some of the structures in a human lung.
Where is the carbon dioxide concentration highest?
Compared with inspired air, which description of expired air is correct?
It has less oxygen and less carbon dioxide.
It has less oxygen and more carbon dioxide.
It has more oxygen and less carbon dioxide.
It has more oxygen and more carbon dioxide.