gas exchange Flashcards
how are the gills adapted for efficent gas exchnage
- gill filaments (Stacked up ontop) increasing SA
- gill lamellae are at right angles to filaments to increase SA
- lots of lamellae SA
- lamellae are thin - short diff pathway
- gills have lots of capillaries - maintain concentration gradient
- gill arch made of cartilage - prevent collapsing
how does water move through the gills
water taken in through the mouth and forced over gills then out through an opening on each side of the body
how counter current flow work?
blood and water flow in opposite directions;
concentration gradient is maintained along the whole of the gill
how are insects adapted for gas exchange
- tracheoles have thin walls - short diff distance
- tracheoles are highly branches - LSA:V
- surrounded by muscles- contract when move, maintain conc gradient
- tracheoles are full of air which increases diff
rings around trachea : stop collapsing - fluid at the end of tracheoles -> faster diff of 02/ co2
how do the respiratory gases move in insect
- along diff gradient;
- respiration occurs more at end of trachea
- conc of CO2 is higher
- net movement is out
- Conc at start of CO2 of trachea is greater
- so net moment to other end - mass transport:
- muscles contract,
- squeezing trachea,
- increasing pressure,
- causing CO2 to be pushed out - end of tracheloes filled with water:
- anaerobic respiration occurs in cells,
- lactate is soluble,
- water conc decreases,
- water moves out of trachea,
- increasing volume of air - diff faster
what are spiracles
tiny pores on surface of insect, allows respiratory gases in and out
how do insects control water loss
they open and close spiracles by a valve
how are plants adapted for gas exchange
- broad leaves, large SA absorb as much light
- arranged to avoid overlap of cells -> prevent shadowing
- thin - most light absorbed first few micrometers
- ## palisade layer contains lots of chloroplasts, near to surface, maximum light
how do plants reduce water loss
- stomata open and close by guard cells
- roll up leaves (increase humid)
- sunked stomata (increase humid)
- thick cuticle - large diff pathway
- lots of hair - increase humid
what happens during inspiration
external intercostal and diaphragm contracts
external intercostal muscles move up and out
diaphragm flatten
increasing volume of thoracic cavity
decreasing pressure
air moves down pressure gradient into lungs
expiration
external intercostal relax diaphragm relax diaphragm dome shape decrease volume of thoracic cavity increase pressure air moves down pressure gradient out of lungs
forced expiration
external intercostal and diaphragm relax
internal intercostal contract
pulls ribcage further down and in
decrease thoracic cavity and increase pressure
air forced out along pressure gradient
how does O2 move in alveoli
air moves from epithelial in alveoli to endothelial cells in capillaries
how are alveoli adapted for efficient gas exchange
- elastic fibres allow alveoli to stretch, fill with air and spring back during expiration to expel carbon dioxide rich air
- lots of alveoli - large SA
- thin walls - short diff pathway
- lots of capillaries - maintain conc gradient
- thin capillaries - RBC flattened against cap walls - short diff, RBC slowed down, more time for diff
tidal volume
volume of air each breath in
