Gas Exchange Flashcards
What is ventilation/breathing?
What product do we obtain from breathing?
What substance do we remove via breathing?
Removal/addition of gases, through the gas exchange system, involved in the chemical reaction necessary for life to take place.
Waste - CO2
Resource - O2
What muscles aid ventilation?
What bone structure aids ventilation?
external/internal intercostal muscles and diaphragm.
ribcage.
What are the 4 steps of inspiration?
- Ex.intercostal muscles and diaphragm contract; diaphragms flattens.
- Ribcage moves up and out.
- Volume increase, pressure decrease.
- Air moves in.
What are the 4 steps of expiration?
- Ex.Intercostal muscles and diaphragm relax; diaphragm curves up.
- Ribcage moves down and in.
- Volume decrease, pressure increase.
- Air moves out.
What is forced expiration?
Active process which requires energy.
Int.Intercostal muscles contract.
Ribcage pulled further down and in.
Pressure + Vol. increases further.
Air moves out forcefully.
Do inspiration and expiration require energy?
Inspiration does.
Expiration does not.
How does air travel to the alveoli?
Air -> Trachea -> Bronchi -> Bronchioles -> Alveoli
How are the lungs adapted for gas exchange?
Large surface area - loads of alveoli.
Good blood supply - capillary network outside of the alveoli.
Short diffusion distance - alveolar epithelial wall ONE CELL THICK -> Capillary outside it.
High conc. gradient - CO2 enters alveoli (co2 devoid)
O2 enters capillaries (O2 devoid)
How are fish adapted for gas exchange?
Gill structures which contain filaments which contain lamella - site of O2 diffusion, LARGE S.A.
GOOD BLOOD SUPPLY - large capillary system through gills.
SHORT DIFF DISTANCE - filaments V.thin.
HIGH CONC. GRADIENT OF GASES.
What is the counter current exchange?
Why is it an advantage?
Water enters mouth one way ->
Fish’ lamellae face against
Water O2
High conc. gradient; obtain a lot of O2 in to bloodstream.
What do insects use for gas exchange?
What are they?
How do they work?
Trachae.
Micro pipes filled with air.
- O2 travels down the conc. gradient into smaller pipes called trachioles.
How does air enter an insect?
Rhythmic abdominal movement allows gases to enter/leave spiracle pores.
How does air enter the systems of insects?
The gases (O2 for eg) diffuses through the thin cell walls.
Why do insects not need exchange systems?
Furthermore, why do insects not transport their gases via the circulatory system?
Small sa:v ratio, gases can reach all parts of the body.
What gases do plants need? Why?
O2 (respiration)
CO2 (photosynth)
