Exchange Surface Flashcards
Name two types of epithelial tissue found in the lungs and airways
Ciliated
Squamous
Explain how alveoli create a surface for efficient gaseous exchange
- wall is one cell thick,shorter diffusion pathway
- elastic so RECOIL, aids ventilation
- maintains concentration gradient
- large number = SA
Why is it bad to have a low surface area of volume ratio
Difficult to exchange
High demand
Diffusion too slow
Define tidal volume
Volume of oxygen inhaled or exhaled
Define vital capacity
Maximum volume of air in one breath
What are the adaptions for squamous epithelium, alveoli, good blood supply and ventilation to improve efficiency of gaseous exchange
SE-short diffusion pathway
Alveoli-larger SA
Good blood supply and ventilation - maintain concentration gradient
Define the name given to the trace showing electrical activity of the heart
Electrodiagram
How do we inhale oxygen
Physical -external intercostal and diaphragm contract
Volume -increases
Pressure-decreases
Moved via pressure gradient
How do we exhale
Physical- external intercostal and diaphragm relax
Volume- decrease
Pressure -increase
Moved via pressure gradient
Describe the structure of the insect gaseous exchange system
Insects uses trachEAE to exchange gases
Air diffuses into the trachea via spiracles
Trachea branch into smaller tubes called trachEOLES where it dissolves to tissue
TrachEOLES - contain fluid, for oxygen to dissolve
How do particularly active insects ventilate during periods of high metabolic demand
Movement of thorax and abdomen causes the change in volume which changes in pressure
How do insects maintain aerobic respiration even in increasingly anaerobic conditions
TrachEOLES contain tracheal fluid which contain water
Aerobic respiration causes the increase in lactic acid in tissues
Water moves out of trachEOLES via osmosis
Exposes more surface area for gaseous exchange
Describe how fish ventilate
Fish opens mouth - lowers buccal cavity, V increase P decreases, water sucked in
Fish closes mouth- rises buccal cavity, V decreases P increases, water forced out of across the gill filaments
What is the name given to the mechanism that maximises gas exchange in the gills
Countercurrent flow
Explain why this mechanism allow more oxygen to enter the blood than when the blood and water flow parallel to each other
Counter current system
blood flows in one direction and water in another
-maintains a large concentration gradient
-concentration of oxygen in the water is always higher than that in blood
Parallel system
-water and blood flow in same direction
-meets equilibrium
