Ventilation

Question 1

What is ventilation? How does it occur?

Answer 1

Ventilation is the exchange of air between the atmosphere and the alveoli. Air moves via bulk flow from an area of high pressure to an area of low pressure.

F=ΔP/R
flow (F) is proportional to the pressure difference (ΔP) between two points and inversely proportional to the resistance (R)

Question 2

What is pulmonary circulation/What is systemic circulation?

Answer 2

pulmonary circulation - O2 into blood from alveoli, CO2 into alveoli
systemic circulation - O2 passes into cells from the capillaries, co2 passes out of cells into capillaries

Question 3

What is the minute ventilation? V E

Answer 3

The total ventilation per minute = the tidal volume multiplied by the respiratory rate
minute ventilation (ml/min) V E = total volume (ml/breath) Vt X respiratory rate (breaths/min) f
eg. 500ml/breath X 12 breaths/min = 6000ml/min

Question 4

What is dead space?

What is anatomical dead space

Answer 4

Spaces in the airways that do not permit gas exchange with the blood
…The new atmospheric air that enters the respiratory system during each respiration that does not ever reach the alveoli before it is exhaled

Question 5

What is alveolar ventilation?

Answer 5

The volume of fresh air entering the alveoli per minute

• This is tidal volume minus the volume of air in the anatomical dead space
• This is the most important factor in the effectiveness of gas exchange

Question 6

What is alveolar dead space?

Answer 6

This is when alveoli have little or no blood supply

quite small in healthy people. may be large in people with lung disease

Question 7

What is physiological dead space?

Answer 7

anatomical dead space plus alveolar dead space

-areas in the airways that have no gas exchange, this is wasted ventilation