Ventilation

Question 1

What is the importance of ventilation?

Answer 1

Ventilation (breathing) ensures that the concentration gradients of CO2 and O2 are maintained

Question 2

Describe what happens during inhalation

Answer 2

• the external intercoastal muscles contract
• the internal intercoastal muscles relax
• ribs move up and out
• the diaphragm contracts
• diaphragm moves up
• pressure decreases
• volume increases

Question 3

Describe what happens during exhalation

Answer 3

• internal intercoastal muscles contract
• external intercoastal muscles relax
• the ribs move down and in
• the diaphragm relaxes and returns to a dome shape
• the pressure increases
• the volume decreases

Question 4

What is the direction of air moving in the lungs?

Answer 4

Air moves down a pressure gradient in and out of the lungs

Question 5

Define tidal volume

Answer 5

The volume of air normally inspired at rest

Question 6

Define ventilation rate

Answer 6

Number of breaths in one minute

Question 7

Define pulmonary ventilation rate

Answer 7

The total volume of air moved in and out of the lungs during one minute

Question 8

Equation which includes pulmonary ventilation, tidal volume and ventilation rate

Answer 8

Pulmonary ventilation rate (dm3 min-1) = tidal volume (dm3) x ventilation rate (breaths per minute)