Exchange Surfaces Flashcards
Why do large organisms have a specalised transport system
They have a small SA:V ratio as diffusion is slower for oxygen to be supplied thus requiring the need for a specalised transport system
What occurs during inspiration
Diaphragm contracts and flattens external intercostal muslces contract causing ribcage to move upwards and outwards
Abdominal muslces contract
What occurs during expiration
External intercostal mucscles relax
Vol. of thorax decreases + pressure increases to that above atmospheric pressure hence air moves out of the lungs
*Internal * intercotsal muscles contract –> pushing ribs down and inwards
Diaphragm moves upwards
What are tissues of the gas exhcange system and what are their functions
Smooth Muscle - Control flow of air
Cartillage walls - ensures air channels remains open at all times / prevents trachea from collapsing
Goblet cells - secrete mucus to trap pathogens
Cilliated epithillium - moves mucus to top trachea
Erythocrytes - provide a good blood supply
Elastic tissue –> Cause recoil of alveoli to return air sac to original size
What is a feature of cartillage
C shaped ring ensures air channel remains open at all times
What are the different adaptions of alveoli
Large network to provide large SA
One Cell Thick so thereis a short diffusuion pathwau
Small size so there is a* large SA:V Ratio*
Lined with squamous epithilium so there is a short diffusion pathway
Surrounded by network of capillaries –> Good blood supply which maintains steep conc. gradient
What is vital capacity
Max. vol of air that can be breathed out in one breath
What is tidal volume
Vol. of air that can be breathed out during normal breathing
What is oxygen uptake
Vol.of oxygen used by someone in a given time
What are precatuions a person should take when using a spirometer
Wash mouthpiece
Use fresh air
What is used to remove CO2 from spiroemeter
Soda Lime
Why is ther a small amount of air(residual vol). that is always retained in the lungs
Thorax cannot be fully compressed
Trachhea is held open by cartiallage
How do insects breathe
Through spiracles-openings in the exoskeleton
How do flying insects recieve rapid O2 intake during flight
Closing spiracles and using abdominal muscles as ventilation
How does more air during flight move into the lungs of insects
Muscle cells start to repsire anaerobically to produce lactae –> lowers water potential of cell therefpre water movs from tracheoles into cells by osmosis which creases vol. of liquid in tracheoles
