Theme 17: Osmo 2 Flashcards
How do marine reptiles get rid of the excess NaCl that their bodies cant handle?
compound tubular glands and salt glands are in their nostrils and eyes are lined with special endothelial cells that secrete hightlyh concentration into tubules, their skin is impermeable to seawater
How do endothelial cells take salt our of the blood?
they use a Na/K pump into the lumen tubule against a concentration gradient
in what form do reptiles and birds get rid of salt out of their bodies?
they cry it out
is it a good idea to drink seawater if you lack salt glands?
No, seawater has a very high concentration, a human kidney can only pee out 2% and the water is 3%
What is the problem with nitrogen waste?
it is xtremely toxic and affects the membrane, uncouples oxidative phosphorylation if abolishes H+ gradient across inner mitochondrial membrane
what is the product of metabolism or proteins and nucleic acid?
nitrogenous waste
what does nitrogenous waste produce?
ammonia
What does nitrogenous waste increase?
glutamate synthesis and effects the CNS
what would accumulation of NH3 result in and how is this avoided?
results in: convulsion, coma, death
must be excreted
What do animals strategies to rid themselves of ammonia differ by?
difference is the water availability that they have
In which order are: a) ammonia b) urea c) uric acid toxic in?
ammonia - hghly toxic
urea - less toxic
uric acid - not toxic at all
How do invertebrates and fish get rid of ammonia?
Invertebrates: diffuse out of the body surface into surrounding water
fish: excreted out of gills from kidney
what do mammels use as a molecule of choice instead of ammonia?
urea
how is urea diluted?
by drinking lots of water to make it less concentrated and lighter colored
why is urea better than ammonia?
tolerated in a more concentrated form
sacrifice less water
healthier for fetus
What animals have nitrogenous waste in the form of uric acid?
birds
insects
most reptiles
What are the advantages of uric acid?
adaptation to limited availability of water
doesnt make the bladder too full
non toxic
What is the relationship between sharks and urea?
they retain urea in blood so that thir body fluids are slightly more concentrated than sea water
Are sharks body fluids __ to seawater?
a) hypertonic
b) hypotonic
c) isotonic
hypertonic
what do kidneys eliminate from sharks?
excess water - urine
do sharks have a lower concentration or higher concentration of Na+Cl- in their blood than the seawater?
higher concentration in blood
what glands excrete NaCl using active transport in Sharks
rectal glands
What is the term for only being able to come with small changes in seawater salinity?
stenohaline
Sharks are stenohaline, what does that mean?
they are only able to cope with small changes in seawater salinity
Are sharks osmoconformers or osmoregulators?
some are regulators and some are conformers
What does euryhaline mean?
able to live in a wide range or salinities
What type of sharks can penetrate fresh water
bull sharks
What glands do active transport in marine birds and reptiles?
salt glands
What do salt glands do?
remove NaCl from the blood against a concentration gradient to produce concentrated tears
What does ammonia come from?
the breakdown of proteins
true or false: NH3 is not very soluble in water so it is not easily removed from fish gills by diffusion.
false, NH3 iis very soluble so it is easily removed from fish gills by diffusion
what species need uric acid and why?
species that need to conserve water
