bevan Flashcards
why do animals lose heat more quickly in water than in air
water has a higher thermal conductivity
what happens when water temperature increases
body temperature increases, oxygen demand increases BUT oxygen content decreases
why does aquatic ventilation use passive through through systems and not tidal
discuss some examples of flow through systems
because too much energy would be required to accelerate and deaccelerate water into an organism (tidal)
polycheate worms have external tenticle fans or external gill tufts
sea stars have tubed feet with gill function
discuss an aquatic animal which performs tidal ventilation
sea cucumber (Holothurian echinoderm) draws water in, oxygen diffuses across respiritory trees before water is pushed back out of the same whole
discuss an aquatic animal that does active oxgen extraction using a through flow system
cephalopods.
squids are hard to work with so octopuses are used for experimentation
water in drawn in over gills through a slit before being forced out of a siphon
what is the process by which fish do respiritory exchange
opercular pumping
water is gulped into mouth, which moves into the operculum cavity. when the cavity is compressed the water is forced out through gills.
discuss the structure of fish gills
gills consist of many tube like structures called filaments, which have folds on their surface called lamellae. blood flows through the lamellae in a counter current direction to water
what ventilaiton method is done by fish swimming at high speeds
how is this different to normal ventilation
ram ventilation
operculum cavity doesnt need to be compressed
this process is less metabolically demanding than normal ventilation
which fish have a large SA;weight ratio
those who are very active, such as mackral
how do terrestrial animals ensure their respiritory surfaces are always kept moist
stay in mosit humid areas or fully enclose their respiritory structures
do terrestrial animals perform through flow or tidal ventilation
mostly tidal
discuss different ventilation methods displayed by terrestrial animals
insects have tracheae and spiricles.
lungfish, amphibians and some reptiles use positive pressure systems. compressing a buccel cavity to force air through respiratory surface
crocodiles and mammals contract muscles which increases the volume of the lungs and create negative pressure which draws air in.
what is a possibly explanation for the fact that birds are better at oxygen extraction compared to similar sized mammals
this system evolved perhaps due to the fact that birds fly at higher altitudes than mamals (over mountains etc)
apart from birds, which is one other group of animals which also perform uni directional ventilation
crocodiles have areas of unidirectional flow
what are the 4 types of circulatory system
systemic; to and from body tissues (high pressure)
pulmonary; to and from lungs (low pressure)
open; blood not contianed in blood vessels or only partially contained in blood vessels
closed; the blood is always contained in the heart or pumping systems
what is an auricle
a cone shaped pouch is the atrium of vertebrates that increases blood holding capacity
describe structural differences between the vessels in the arterial and venous sytems
arterial system vessels have a narrow lumen to maintain high pressure, and a thick layer of smooth muscle, elastin and collagen for stregth to withstand the pressure
the vessels in the venous systems have a wide lumen, and thin walls containing little smooth muscle etc because high pressure is not needed
the venous system has valves present to prevent backflow
how is the flow of blood altered
changing pressure or resistance, for example changing the lumen diameter of the vessel by vasoconstriction or vasodialation
how did the heart evolve
a muscular tube elongated and bent back against itself and certains regions evolved spatially
name how vasodialation can be brought about
a tissue that is doing a lot of metabolic work will have high concentrations fo CO2 and therefore decreased pH, which signals for vasodialation and therefore increased blood flow which replensihes oxygen concentration and removes waste products
why are respiritory pigments used
respiritory gasses need to be transported, and transport in solution is not efficient
what is something all respiratory pigments have in common
they are metalloproteins (proteins with a metal element)
have more than one subunit and are allosteric
fe
they bind reversibly to oxygen
there is a positive correlation between pO2 and % saturation
name some of the adaptions animals thts fly have
they ventilate quickly, but this doesnt cause hypocapnia (loss of co2 leafing to vasoconstriction and anoxia)
relatively large hearts comapred to similar sized mammals
small muscle fibres so oxygen diffuses quickly
many capillaries
very good at fat metabolism, which mammals arent
unique features to high flyers
large lungs to increase surface area for diffusion
more effective breathing pattern
haemoglobin has a higher affinity for oxygen
mitochondria have been redistributed and are close to the capillaries so Atp can be used to increase rate of oxygen diffusion
discuss isotonic, hypotonic and hypertonic environments
isotonic; ion concentration insode and outside of RBC’s is the same
hypertonic; ion concentration outside RBC’s is higher than inside them; water leaves RBC’s
hypotonic; ionic concentration outside a RBC is lower than inside the RBC; water moves into RBC’s and causes rupture
what are 2 general methods of osmoregulating
changing the permeability of membranes
actively transporting ions
why are rockpools are difficult environment
salinity changes as water evaporates and sea water hits etc
where can soft and hard water be found
soft water; lakes
hard water; rivers
what is the primary osmoregulation organ
kidney
why can the waxy monkey frog and the chiromantis frog survive long periods of time in dry environment
they have impeareable skin with a waxy substance on it. it melts when its hot
what part of a reptile is impeareable to water loss
scales
which animal has 90% of its water gain from metabolic water (breakdown of sugars etc)
kangaroo rat
how do animals have to modify air thats being breathed in order to extract oxygen from it
air must be heated up to 38 degrees and water must be added to increase the relative humidity to 100%
air that is breathed out has water in it, how do kangaroo rats minimise this water loss
their nasal structures have swirled bones that increase the surface area for water extraction via the counter current blood system
how do marine vertebrates osmoregulate differently to terrestrial vertebrates
reniculate kidney (many small lobes)
