Urinary Systems and Electrolytes II

Question	Answer
Osmoregulation	Maintenance of constant/near constant blood plasma OSP
Osmoconformer	Follow isosmotic line by matching blood OSP to enviro OSP
Ionic regulation	Ionoregulators ionoconformers
Volume regulation	self explanatory
FW crab kidneys (4)	1. Regulate volume only 2. water by osmosis = urine excreted 3. Haemolymph isotonic w urine 4. Haemolymph hyperosmotic to water
What is a hyperosmotic regulator?	All FW animals BOP is hyper to H2O
What challenges to FW fish face?	Volume reg - H2O constantly enters body from dilute enviro. Osmotic reg - Entering H2O lowers the ECF OSP Ionic reg - Ions move from ECF to more dilute surrounding water Entering water also dilutes the ECF
What are FW gills comprised of?	90% Pavement cells for O2 uptake MRC cells which are Cl- channels, ion channels
What compromise must gills make?	If more MRC then less O2 uptake
How do marine fish gain water?	Integuments and epithelia of marine fish are poorly penetrated by SW Drink SW, co-absorbed in gut epithelia with monovalent ions
What problem does this pose?	Upsets ionic regulation
How do marine fish excrete waste?	Divalent ions from kidneys Na+/Cl-/nitro. waste from gills

Resource summary

	Created by J yadonknow over 6 years ago