gas exchange

Question 1

what is gas exchange?

Answer 1

the exchange of o2 and co2 in the alveoli

Question 2

what are all features in gas exchange surfaces limited to?

Answer 2

• large surface area
• thin wall/membrane
• good blood supply
• good ventilation with air

Question 3

what experiments are used to test for co2 levels in air?

Answer 3

• hydrogen carbonate
• limewater

Question 4

what is the positive result to a hydrogen carbonate test?

Answer 4

pink/red to yellow

Question 5

what is the negative result to a hydrogen carbonate test?

Answer 5

pink/red to purple

Question 6

what is the positive result to a limewater test?

Answer 6

clear to milky

Question 7

what is the negative result to a limewater test?

Answer 7

remains clear

Question 8

what is the % of o2 in inspired air?

Answer 8

21%

Question 9

what is the % of o2 in expired air?

Answer 9

16%

Question 10

what is the % of co2 in inspired air?

Answer 10

0.04%

Question 11

what is the % of co2 in expired air?

Answer 11

4%

Question 12

what is the % of water vapor in inspired air?

Answer 12

0.2 - 4%

Question 13

what is the % of water vapor in expired air?

Answer 13

5 - 7%

Question 14

what is the % of nitrogen in both inspired and expired air?

Answer 14

78%

Question 15

when is the composition of oxygen highest?

Answer 15

in inspired air

Question 16

when is the composition of carbon dioxide highest?

Answer 16

in expired air

Question 17

when is the composition of water vapor the highest?

Answer 17

in expired air

Question 18

what is the order of the pathway of air?

Answer 18

nasal cavity → pharynx → trachea → bronchus → bronchioles → alveoli

Question 19

when breathing in, the internal intercostal muscle ______, the external intercostal muscle and diaphragm ______, and the pressure in the alveoli _____

Answer 19

relaxes, contracts and decreases

Question 20

when breathing out, the internal intercostal muscle ______, the external intercostal muscle and diaphragm ______, and the pressure in the alveoli _____

Answer 20

contracts, relaxes and increases

Question 21

why is does the trachea have c-shaped rings?

Answer 21

to accomondate the oesophagus when peristalsis is taking place (the gaps/open part allow the lumps of food to pass through)

Question 22

how does the breathing system protect itself from pathogens and bacteria?

Answer 22

• goblet cells: produces mucus
• mucus: sticky substance that traps pathogens
• ciliated cells: moves the mucus away from the part of the organ up into the mouth to be swallowed.

Question 23

what are the effects of physical activity on breathing?

Answer 23

• increased frequency of breathing
• increased depth of breathing

Question 24

why is there increased depth and frequency of breathing during physical activity?

Answer 24

bc the muscles are working harder and aerobically respire more bc they need more oxygen to be delivered to them.

(this is also to avoid the production of lactic acid, which can lower the pH of cells and denature enzymes)

Question 25

what is oxygen debt?

Answer 25

a temporary oxygen shortage in the body tissues arising from exercise.