Gas Exchange Flashcards
Respiration
A chemical reaction that releases energy from organic molecules and transfers it to ATP
Gas exchange
A consequence of respiration/ photosynthesis
Ventilation
Forcing water or air in or out so that a diffusion gradient is maintained
(In animals)
Gas exchange in single cell organisms like bacteria and algae
Via diffusion
As they are small so have a large SA:V
Gas exchange in insects
Air enters through spiracles in the abdomen and thorax which open and close according to the insects needs
Coverings ensure an unidirectional flow of air
Spiracles open to trachea that branch into tracheoles that are kept open by rings of chitin
The walls of the tracheoles are very thin and pass close to the muscle fibres or enter cells which allows for. Avery short diffusion pathway
Diffusion of O2 in the gaseous phase is a lot quicker than if the O2 were dissolved in water
Abdominal pumping
During ventilation art rest the muscles contract drawing air in through spiracles
To maintain a concentration gradient when the insect is active the air is expired through different spiracles to those of which it entered through
Maximising SA
- gas exchange in insects
When at rest the tracheoles are filled with fluid. When active this water moves into the muscle cells via osmosis inc the SA in the thracheole this is bc. The muscle cells respire anerobically and therefore decrease the W.P. Allowing a concentration gradient for the water to move int the cell via osmosis
Therefore there is more space for more air to be drawn in
How is CO2 removed in insects
It diffuse into the blood and out through the cuticle
However some does escape through spiracles
How is water loss dec in insects
Small SA:V
Waterproof layer and right chitin exoskeleton
Spiracles close
O2 in water
1% in water- 20% in air Not very stable Slower diffusion More dense so harder to move Nit enough O2 to support endothermy
Best O2 content in water
Water is
Cold- more O2 can dissolve
Clean- no bacteria respiring
Turbulent- maintained conc gradient
Gas exchange in fish
Water passes over flat plates called filaments in the gills
On top of the surface of these filaments are projections called lamellae that increase the SA
There is a short diffusion pathway as only membrane between blood and water
There is a counter current flow
Counter current flow
Maintains the diffusion gradient by inc the opportunity for O2 to diffuse and avoiding equilibrium
Gas exchange in mammals
- anatomy
Nasal cavity Epiglottis Trachea Bronchus- w/ rings of cartilage Lung ( pleural membrane - 1covers ribs, 1 covers lung w/ pleural space between the two ) Bronchioles- w/ rings of cartilage Terminal bronchioles - smooth muscle Alveoli
Where does Asthma occur
Bronchioles
What can trigger the allergic reaction ( asthma )
Dust
Pollution
Pollen
Exercise
Asthma cause the bronchioles to have
More mucus and thicker muscle
The alveoli is made up of
This cells - squamous epithelium ( alveolar epithelium )
tissue that lines bronchi and bronchiole is made up of
- what does it do
Ciliates columnar epithelium
- stops dust and bacteria penetrating the lungs
