gas exchange in humans Flashcards
1
Q
draw and recall the structure of the lungs
A
- trachea
- bronchus
- bronchioles
- alveoli
- lungs + ribs
- internal and external intercostal muscles
- diaphragm
2
Q
surface area of alveoli
A
- lots of alveoli create high surface area to volume ratio
- surrounded by many capillaries
3
Q
how is the concentration gradient of the alveoli maintained?
A
- ventilation means air with a HIGH concentration of oxygen replaces air with low concentration of oxygen
- circulation of blood in capillaries means blood HIGH in oxygen is replaced with blood that is low in oxygen
4
Q
epithelium of capillaries and alveoli
A
- epithelium is very thin so diffusion distance is short
5
Q
tidal volume
A
volume of air breathed in or out per breath at rest
6
Q
breathing rate
A
number of breaths per minute
7
Q
pulmonary ventilation
A
total volume of air breathed in in a minute
8
Q
oxygen consumption
A
volume of oxygen used per minute (respiration)
9
Q
equation for pulmonary ventilation
A
pulmonary ventilation = tidal vol x breathing rate
10
Q
inspiration
A
- diaphragm contracts so it flattens
- external intercostal muscles contract so ribs move up and out
- so volume of thorax increases
- so pressure decreases
- so air moves IN from high to low pressure
11
Q
expiration
A
- diaphragm relaxes so becomes domed
- external intercostal muscles contract so ribs move down and in
- so volume of thorax decreases
- so pressure increases
- so air moves OUT from high to low pressure
12
Q
what happens in FORCED expiration?
A
as well as normal things
- internal intercostal muscles contract
- so ribs move down and in further
