Unit 11 - Breathing

Question 1

What is the equation for respiration? ( 1 )

Answer 1

Glucose + Oxygen —-> Carbon Dioxide + Water +ATP ( Energy )

Question 2

How are alveoli adapted for efficient gas exchange? ( 4 )

Answer 2

• They have a large surface area
• They have moist surfaces
• They are one cell thick ( short diffusion distance )
• They have a good blood supply ( to maintain a concentration gradient )

Question 3

What does the diaphragm do when you breathe in, and when you breathe out? ( 2 )

Answer 3

• When you breathe in: It contracts and flattens

- When you breathe out: It relaxes and is pushed up

Question 4

What does your chest do when you breathe in, and when you breathe out? ( 2 )

Answer 4

• When you breathe in: it expands

- When you breathe out: it contracts

Question 5

What does the volume and pressure inside the lungs do when you breathe in, and when you breathe out? ( 2 )

Answer 5

• When you breathe in: the volume increases, so pressure decreases
• When you breathe out: the volume decreases so pressure increases

Question 6

What happens to the air in your lungs when you breathe in, and when you breathe out, in terms of pressure? ( 2 )

Answer 6

• When you breathe in: air flows into lungs from high to low pressure
• When you breathe out: air flows out of lungs from low to high pressure

Question 7

What is the Vital Capacity? And what is the adult average? ( 1 )

Answer 7

• The maximum volume of air that your lungs can take in

- Adult average is 5 Litres

Question 8

How much air is inhaled and exhaled at rest? ( 1 )

Answer 8

-1.5 L of air

Question 9

Why do you breathe at a faster rate when doing exercise? ( 2 )

Answer 9

• This is because your muscles need more oxygen for aerobic respiration, and they produce more carbon dioxide
• By breathing faster, you inhale more oxygen and exhale more carbon dioxide

Question 10

Since breathing happens automatically, how does you brain know when to increase your breathing rate? ( 2 )

Answer 10

• Your brain can detect the pH of the blood

- Increased CO2 levels decrease the blood’s pH ( bc CO2 is acidic )

Question 11

How does your brain make you breathe faster?

Answer 11

• It sends nerve impulses to the diaphragm, making you breathe faster
• Breathing faster returns blood CO2 levels and pH back to normalcby removing it from the lungs

Question 12

In what ways is the “balloon lungs” model not 100% accurate

Answer 12

• The diaphragm needs to be directly below the lungs
• The diaphragm isn’t curved
• The expansion of the ribcage when inhaling is not shown

Question 13

What % of inspired air is Nitrogen? ( 1 )

Answer 13

79%

Question 14

What % of inspired air is Oxygen? ( 1 )

Answer 14

21%

Question 15

What % of inspired air is Carbon Dioxide? ( 1 )

Answer 15

0.04%

Question 16

What % of expired air is Nitrogen? Why? ( 2 )

Answer 16

79%

- It is not used up by body processes

Question 17

What % of expired air is Oxygen? Why? ( 2 )

Answer 17

16%

- It is used up in respiration

Question 18

What % of expired air is Carbon Dioxide? Why? ( 2 )

Answer 18

4%

-It is produced in respiration