Chapter 7 Key Concepts Flashcards
Why are the amoeba able to rely on diffusion alone?
Low metabolic activity . So low oxygen demands and low CO2 production
Large SA: V
4 charateristics of a specicalised exchange surface
Increased SA
Thin layers
Good blood supply
Ventilation to maintain diffusion gradient
Why the increased SA for exchanged surfaces
Provides area needed for exchange
To overcome limitations of SA:V eg root hair cells and villi
Why the thin layers for exchanged surfaces
Short diffusion distances
Process is fast and efficient
Eg alveoli and villi
Why the good blood supply for exchanged surfaces
Steeper con grad means faster diff
Ensures substances constantly being removed and delivered to ex surface maiming steep con grad eg alveoli gills and villi
Why the ventilation for exchanged surfaces
For gases
Helps maintain steep con grad for increased efficiency
Eg alveoli and fish (flow of water carrying dissolved gas)
Adaptations of the nasal cavity
Large SA with good blood supply that warms air to room temp
hairy lining that secreted mucus to trap dust and bacterial protecting delicate lung tissue from irritation and infection
Moist surfaces, increase the humidity of incoming air to reduce Evap from the exchange surface
Adaptations of the trachea
Main airway carrying clean warm moist air from nose to chest
Strong flexible Incomplete Cartilage rings
-stop trachea collapsing
-incomplete so food can move down the oesophagus behind the trachea
Lined with ciliated epith cells with goblet cells between and below the cili epith
Adaptations of the bronchus
Left and right. Each leading to the lung.
Similar structure to trachea
Same supporting rings of cartilage but smaller
Adaptations of the bronchioles
No cartilage
Walls have smooth muscle
-smooth muscle contracts, the bronchioles constrict and vice versa
-some gas ex poss as they’re lined with thin layer of flattened epith
Adaptations of the alveoli
Epithelial cells, collagen, elastic fibres for elastic recoil so alveoli can stretch as air drawn in and they help squeeze air out Large SA Thin layers Good blood supply Good ventilation
Why does an alveoli need a large SA
If the lungs were like balloons SA nah big buff for amount of O2 needed to diffuse into the body
Why does an alveoli need thin layers
Alveoli and Capps have one epithiual cell thin
Thin diffuse distance entre blood and air
Why does an alveoli need good blood supply
Brings CO2 and carries away O2, maintain a steep con grad
Why does an alveoli need good ventilation
Breathing moves air in and out of the alveoli helping maintain steep diff gradients
Role of the lung surfactant
The inner layer of the alveoli is convered in a solution of water salts and lung surfactant
Surfactant makes it possible for alveoli to remain inflated
O2 dissolves in water before diffusing into the blood but also can Evap into air the in the alveoli
What happens to the tidal volume and breathing rate as you exercise
Tidal vol of air moved in each breath increase from like 15 to 50 percent of the vital capacity
Breathing rate increases too so incre
how is more SA exposed for gas exchange in an insect
when ox demand builds up, lactic builds up in tissues so water moves out of trachioles via osmosis
how do larger insects eg beetles locust and grasshoppers with very high energy demands supply the excess oxygen they need
mechanical ventilation of the tracheal system
collapsible enlarged tracheae or airs sacs that act as reservoirs
explain the use of collapsible enlarged tracheae or airs sacs that act as reservoirs in larger insects
used to increase amount of air moved thorough the gas ex system
usually inflated and deflated by the ventilating movements of the abdo and thorax
how does the mechanical ventilation of the trachael system
air actively pumped into the system by muscular pumping of the abdo and or thorax
pumping changes the vol of bod
as pressure of the tracheae and tracheoles changes air moved in or expelled out
why do fish need special respiratory systems?
water is viscous and has less o2 in it
it would use up too much energy to move viscous water in and out of lung like things
-SA V too small
-scales doesn’t allow gas ex
describe the process of ram ventilation
ram water past the gills. meaning they cant stop moving
in what primitive species does ram ventilation happen
cartilaginous fish eg sharks and rays
5 adaptations of the thin feathery gills
large SA for diff rich blood supply to maintain steep grad for diff thin layers so short diff distance countercurrent exchange system tips of adjacent gill filaments overlap
what does it mean if the tips of the gill filaments overlap?
increased resistance to flow of water over the gills
slows down movement of water
more time for gas ex to occur
