P1 14. The Respiratory System

Question 1

what are the two roles of the respiratory system

Answer 1

it brings oxygen into the body so that it can help produce energy aerobically

it gets rid of carbon dioxide as a waste product which is produced when we exercise

Question 2

what is in inhaled air

Answer 2

nitrogen 78%
oxygen 21%
carbon dioxide 0.03%
others 0.97%

Question 3

what is in exhaled air

Answer 3

nitrogen 78%
oxygen 16%
carbon dioxide 4%
other gases 2%

Question 4

what is the mechanics of breathing in
inhalation

Answer 4

1. diaphragm and inter coastal muscles contract
2. diaphragm flattens and pulls the bottom of the lungs down
3. intercostal muscles pull the ribs up and the lungs down
4. lung increases in size and air pressure inside the lungs is reduced
5. air pressure outside body is now higher than the air pressure inside body. air travels from high to low areas of pressure so air is pulled into the lungs

Question 5

the mechanics of breathing out
exhalation

Answer 5

1. diaphragm and inter coastal muscles relax
2. diaphragm moves back up into a dome shape
3. intercostal muscles relax and all ribs and lungs to move inward
4. lung decrease in size and air pressure inside the lungs is increase
5. air pressure outside body is now lower than the air pressure inside body. air travels from high to low areas of pressure so air leaves the lungs

Question 6

what’s the difference between inhaled and exhaled air

Answer 6

oxygen decreases from 21% - 16%

CO2 increase 0.04% to 4%

Question 7

why is there a difference in the air exhaled vs inhaled

Answer 7

oxygen is needed in aerobic respiration by working muscles releasing energy.

CO2 is a waste product coming from the working muscle