Gas Exchange Flashcards
Name two features of a gas exchange surface
Thin- short diffusion distance
Large surface area
Name two adaption of gills for gas exchange
Llamella give large surface area
Counter current flow maintains conc gradient
What do hairs do
Trap water vapour
why do single celled organisms not need specialised exchange surfaces?
as the substances can diffuse directly in or out of the organism due to a short diffusion distance
outline the order of the structures in the respiratory system
Trachea —> bronchi —> bronchioles —> alveolar ducts —> alveoli
how does the alveoli structure maximise gas exchange?
there are many alveoli
-so large surface area
they are one cell thick
-so short diffusion distance
Describe how oxygen from the air in the alveolus enters the blood
Diffuses across the capillary epithelium and the capillary endothelium into the blood
why is breathing out difficult in fibrosis
as there is Loss of elasticity
so Less recoil of alveoli
outline the process of inspiration
Diaphragm contracts and moves down External intercostal muscles contract ribs move up and out. Volume increases, pressure decreases Air moves in down pressure gradient
what is different in forced expiration from regular expiration
the internal intercostal muscles contract
outline the process of expiration
Diaphragm relaxes and moves up External intercostal muscles relax ribs move down and in Volume decreases, pressure increases Air moves out down pressure gradient
what is tidal volume
The volume of air moved in/out of lungs with each breath
what do gill fillaments provide?
a large surface area for exchange of gases
what do lamellae do to gill fillaments
further increase the surface area for gas exchange
explain the advantage of the one way flow of water over the gills
it needs less energy
what do tracheoles provide
a short diffusion pathway for oxygen to directly diffuse into a body cell
how do gases diffuse into insects down a diffusion gradient
oxygen used up in respiration creating diffusion gradient for oxygen diffuses into cells from atmosphere down trachea down tracheoles
carbon dioxide produced in respiration so it diffuses out of cells out of tracheoles and out trachea
how do insects move air in and out of the spiracles
insects use rythmic abdominal movements to move air in and out of the spiracles
where does gas exchange occur in an insect
between gas in the tracheole and the tracheal fluid
what can insects do to their tracheal fluid to increase surface area for gas exchange
they can retract their tracheal fluid to increase surface area for gas exchange
what are the pores on an insects body called
spiracles it is where gases enter and leave the insect
why do small organisms not have specialised exchange surfaces
as they have a large enough surface area
compared to their volume
to allow effcient exchange to occur
how do insects reduce water loss
by closing their spiracles
waterproof waxy cuticle around their body
tiny hairs near spiracles which both reduce evaporation
