ventilation, lung anatomy

Question 1

alveoli structure

Answer 1

• large SA
• dense capillary network
• large cg

Question 2

describe the gross structure of the human gas exchange system and how we breathe in and out

Answer 2

trachea, bronchi, bronchioles, alveoli
- breathing in: diaphragm contracts and external intercostal muscles contract
- thoracic cavity volume increase
- pressure in lungs lower than atmospheric pressure
- air moves in
breathing out: diaphragm relaxes
internal intercostal muscles contract
- thoracic volume decreases and pressure inside lungs greater than atmosphere
- air moves out

Question 3

how does oxygen enter the blood?

Answer 3

• O2 diffuses across the squamous EPIthelial membrane and ENDOthelial wall of the capillary
• higher to lower conc

Question 4

pulmonary ventilation

Answer 4

Pulmonary ventilation rate (dm2/min) = tidal volume (dm3) x breathing rate (min-1)