Semester 2: L2 - Ventilation of the lungs - inspiration and expiration

Question 1

what affects partial pressure?

Answer 1

temperature and the number of molecules present

Question 2

Air is a mixture of ___ gases, each with its own _____ ______

Answer 2

1. several
2. partial
3. pressure

Question 3

what gases make up air?

Answer 3

N2 - 79.6
O2 - 21.2
CO2 - 0.004
H2O - 0.5

Question 4

flow =

Answer 4

pressure difference/ resistance

Question 5

pressure difference =

Answer 5

atmospheric pressure - alveolar pressure

Question 6

what’s Boyle’s law?

Answer 6

P1V1 = P2V2

Question 7

whats the process of inspiration?

Answer 7

1. Diaphragm and ext. intercostals contract and chest expands
2. “Pull” makes intrapleural pressure more subatmospheric
3. Increases transpulmonary pressure
4. Lungs expand
5. Alveolar pressure subatmospheric
6. Air flows into alveoli

Question 8

whats the process of expiration?

Answer 8

1. Diaphragm and ext. intercostals relax
2. Intrapleural pressure less subatmospheric
3. Decreases transpulmonary pressure
4. Lungs recoil
5. Alveolar pressure increases
6. Air flows out

Question 9

Expiration results from ……

Answer 9

passive recoil of lungs and ribcage

Question 10

What happens if intrapleural pressure = atmospheric pressure?

Answer 10

This would happen if a hole was inserted in the chest, so that there was continuity between the outside and the intrapleural cavity.

Question 11

what are Two determinants of lung compliance?

Answer 11

elasticity
surface tension (ST) forces

Question 12

what is Pulmonary Surfacant ?

Answer 12

mixture of lipids and proteins which is secreted by the epithelial type II cells into the alveolar space

Question 13

what does pulmonary steps?

Answer 13

Lowers surface tension at air-liquid interface in alveoli