BIOL 225 Chapter Notes - Chapter 44: Aorta, Nephridium, Hairpin Turn
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Osmoregulation: regulation of solute concentrations and water balance by a cell or organism. Excretion: the disposal of nitrogen-containing metabolites and other waste products. Osmolarity = tonicity (conc of solute in solvent) Hyperosmotic = hypertonic (hyper=higher) solution a has a higher conc of solute than solution b. Hypoosmotic = hypotonic = lower conc of solute. Osmoconformer = an animal that is isosmotic with its environment. Osmoregulator = an animal that controls its internal osmolarity independent of the exernal environment. Stenohaline = referring to organisms that cannot tolerate substantial changes in external osmolality. Euryhaline = referring to organisms that tolerate substantial changes in external osmolarity. Most marine animals are osmoconformers (sponges, molluscs . ) Osmotic water loss through gills and other parts of body surface. Excretion of salt ions and small amounts of water in scanty urine from kidneys. Gain of water and salt ions from food and by drinking sea water. Active transport proteins actively pump out salt ions from gills.
