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
