Non Human Gas Exchange Flashcards
How is the tracheal system in insects adapted?
Thin- short diffusion pathway
Highly branched- increases SA:V
How is a concentration gradient maintained in inscets?
Rythmic abdominal movements- compresses tracheal tubes facilitating ventilation- increases the amount of fresh oxygen rich air that reaches the gas exchange surface- tracheoles- maintains an oxygen concentration gradient
Mechanism for gas exchange in insects
Oxy used up and CO2 produces in areboic respiration in tissues
Air moves into spiracles
Into tracheae
Gas exchange occurs at tracheoles directly to cells
Oxygen difusses down concentration gradient into respiring cells
Adaptations in fish
Gill filaments covered in many lamella- large SA
Lamella one cell thick- short difussion pathway
Counter current mechanism- blood oxy flow opposite over lam main conc grad
Vast network of capillaries- maintenance of conc grad
Adaptations of insects to prevent water loss
Thick waxy cutticle
Spiracles can open and close
Adaptations of leaves for efficient gas exchange
Interconnected air spaces in mesophyll layer ( gases come into contact with mesophyll cells)
Many stomata close together
Thin
Flat
Usefulness of stomata that are close together/ many of them
Large surface area for gas exchange
Adaptations of xerophytes to reduce the rate of transpiration
Spines/needles instead of leaves
Hairs, pitted/ sunken stomata, rolled leaves
Thick waxy cuticle
What is the advantage of one way flow?
Requires less energy
Describe the countercurrent exchange mechanism
Blood flows over the gills (lamellae) in opposite directions
Blood always passes water with a higher oxygen concentration
A concentration gradient of oxygen is maintained across the entire length of the lamellae- diffusion is able to take place across the entire length
