Breathing and effects of smoking

Question 1

Why do complex multicellular organisms require specialised breathing systems

Answer 1

This is because the human body contains so many different types of cells and organs that work together and need to keep the body stable

Question 2

Composition of inhaled air (oxygen, nitrogen, carbon dioxide)

Answer 2

Oxygen: 21%
Nitrogen: 79%
Carbon dioxide: 0.04%

Question 3

Composition of exhaled air (oxygen, nitrogen, carbon dioxide)

Answer 3

Oxygen: 16%
Nitrogen: 79%
Carbon dioxide: 4%

Question 4

What are the alveoli’s

Answer 4

The site of gas exchange

Question 5

How are the alveoli’s adapted to form the function of gas exchange (3 reasons)

Answer 5

• contain blood capillaries
• have thin and moist walls
• have a high diffusion gradient

Question 6

What is CHD?

Answer 6

Community human development

Question 7

Breathing in process (inhalation)

Answer 7

• Diaphragm contracts
• External intercostals contract
• Chest cavities increases in volume pressure inside decreases
• Atmospheric pressure is higher than in the lungs
• Air flows from high to low pressure into the lungs

Question 8

Breathing out process (exhalation)

Answer 8

• Diaphragm relaxes
• Internal intercostals contract
• Chest cavity decreases in volume
• Pressure inside increases
• Atmospheric pressure is lower than in the lungs
• Air flows from high to low pressure exits the lungs