Osmoregulation Flashcards
why is osmoregulation important
concentrations need to be suitable for biochemistry
some metabolic wastes are toxic
what are osmoconformers
dont regulate internal conc
most marine invertebrates are
osmoconformers
most marine vertebrates are
osmoconformers but ionoregulators
what are osmoregulators
can adjust internal concentration
elasmobranchs (sharks and rays)
use urea to regulate internal concentration
how do air breathing marine vertebrates maintain concentration
- mammals: kidneys excrete salt
- birds and reptiles: salt glands as kidneys are inefficient
problems with living in freshwater env?
hypoosmotic
how can hypoosmotic freshwater be overcome?
ion uptake proteins in gills
reducing permeability to water (slime)
having active transport
where is ammonia formed
in kidney - deamination of proteins and nucelic acids
describe ammonia
toxic
in fish as water soluble and easily diffusible through gills
describe urea
water soluble
low toxicity
some energy needed to form
describe uric acid
a lot of energy
water insoluble; paste
low toxicity
general steps in renal shit?
filtration: filtrate from afferent renal arteriole goes into glomeruli/bowman’s capsule. enables water and salts to pass but not other things.
reabsorption: blood reabsorbs useful substances from
secretion (unwanted substances from blood put into distal tubule)
excretion
describe how a hyperosmotic region is formed
in ascending region of loop of Henle, NaCl leaves but water cant. this creates hyperosmotic region. causes water to leave distal tubule and enter vas erecta.
