Osmotic Regulation Flashcards
What are osmoconformers?
organisms whose body fluid is the same osmolarity as their environment
What type of organisms are osmoconformers typically?
most marine invertebrates
What exactly is osmolarity?
total number of solute particles in a solution
What are osmoregulators?
organisms whose body fluid is not the same as their environment
What type of organisms are osmoregulators?
most marine vertebrates and everyone else
Why is it hard to maintain osmolarity?
because our cells are constantly breaking down amino acids, so ammonia is formed (which is toxic)
What do organisms that live in the water do to get rid of the ammonia?
they use gills and do diffusion to get the ammonia out of the body
What do mammals, fish, and amphibians do to the ammonia?
ammonia is converted to urea in the liver and is excereted via the kidneys
What is a disadvantage to converting ammonia to urea?
it requires a lot of water
What do reptiles, birds, and insects do to the ammonia?
they convert ammonia to uric acid in order to save water
What is a disadvantage to converting ammonia to uric acid?
high energy cost
What is the purpose of bird and mammal kidney?
to produce urine more concentrated than body fluids
What transports the blood to the kidney?
renal artery
What are the three levels of the kidney (start from the top)?
- renal cortex
- renal medulla
- renal pelvis
What part of the kidney conducts the filtration?
nephron
What are the two types of nephron?
juxtamedullary and cortical
What kind of urine do freshwater fish make and why?
they make dilute urine because they use the kidney to excrete excess water not waste (they remove waste by passive diffusion)