Human Gas Exchange System

Question 1

Inspiration - EIM

Answer 1

• external intercostal muscle contracts
• pull ribs up and out

Question 2

Inspiration - IIM

Answer 2

internal intercostal muscle relaxes

Question 3

Inspiration - Diaphragm

Answer 3

Contracts, moves down and flattens

Question 4

Inspiration - Air pressure

Answer 4

air pressure in lungs drops then rises above atm pressure
as air moves in

Question 5

Inspiration - Lung volume

Answer 5

lung volume increases

Question 6

Inspiration - Air movement

Answer 6

air moves into lungs atm pressure is higher than thorax
pressure

Question 7

Expiration - EIM

Answer 7

Relaxes

Question 8

Expiration - IIM

Answer 8

Contract to pull the rib down and in

Question 9

Expiration - Diaphragm

Answer 9

Relaxes to move up and dome

Question 10

Expiration - Air pressure

Answer 10

Initially greater than atm pressure, drops as air moves out

Question 11

Expiration - Air movement

Answer 11

Air moves out of lungs at thorax pressure is higher than atm pressure

Question 12

Pulmonary ventilation

Answer 12

Total volume of air moved into the lungs during 1 min
PV = tidal volume dm-3 * ventilation rate min-1