Breathing

Question 1

Explain the steps of inhalation (use the acronym DECPAA)

Answer 1

• Diaphragm contracts
• External intercostal muscles contract
• Chest cavity increases in volume
• Pressure inside the lungs decreases
• Atmospheric pressure is higher than in the lungs
• Air flows from high to low pressure, into lungs

Question 2

Explain the steps of exhalation (use the acronym DICPA)

Answer 2

• Diaphragm relaxes
• Internal intercostal muscles contract
• Chest cavity decreases in volume
• Pressure inside the lungs increases
• Air flows from high to low pressure, exit lungs

Question 3

Put these terms in order to show the pathway of oxygen to the blood cell:
red blood cell, bronchioles, capillary wall, alveoli, nostril, epiglottis, pharynx, bronchus, trachea

Answer 3

Nostril -> Pharynx -> Epiglottis -> Trachea -> Bronchus -> Bronchioles -> Alveoli -> Capillary wall -> Red blood cell

Question 4

Give the percentage of oxygen in the atmosphere in:
a) inhaled air
b) exhaled air

Answer 4

a) 21%
b) 17%

Question 5

Give the percentage of carbon dioxide in the atmosphere in:
a) inhaled air
b) exhaled air

Answer 5

a) 0.04%
b) 4%

Question 6

Why is there less oxygen in exhaled air vs inhaled air?

Answer 6

There is less oxygen because it is used up during respiration.

Question 7

Why is the more carbon dioxide in exhaled air vs inhaled air?

Answer 7

There is more carbon dioxide because it is produced during respiration.

Question 8

What sweeps bacteria out of the lungs?

Answer 8

Cilia cells

Question 9

What traps bacteria and viruses in the lungs?

Answer 9

Mucus/phlegm