Zusammenfassung der Ressource
Alveoli Features
& Breathing
- Alveoli features
- Diffusion distance
- Single layer of cells - rapid gas
exchange
- Increased surface area
- Great number of alveoli
- Dense network of capillaries
- Supply of blood with low O2 & high
CO2 concentration
- Secretion of fluid
- Allows gases to dissolve & prevent
sides of alveoli sticking
- Cilia
- fine 'hairs' on cell surface
- Beat in a co-ordinated way to carry
mucus ( with trapped microbes & dust)
away from the lungs
- Goblet cell
- Produces sticky mucus &
releases it onto the cell surface
- Breathing
- At rest
- CO2 level & blood pH are kept at safe level
- During exercise
- more air must be breathed in & out
as muscle have to work harder
- Deeper more rapid breathing
- More CO2 lost from lungs
- Deeper more rapid heartbeat
- More blood pumped to tissues to
carry CO2 away