Final Exam Flashcards
(159 cards)
How do organisms maintain ion and water balance?
Osmotic homeostasis, ionic homeostasis, removal of nitrogen.
What are regulators?
Organisms that have an internal environment different than the external environement.
What are conformers?
Organisms with a similar internal and external environment.
What are examples of conformers or regulators?
Iono or osmo conformers/regulators. Can be either/ or.
What impacts ion and water balance?
The environment and ingested materials (food/water)
What are stenohaline organisms?
Organisms that have a narrow range of external environment they can survive in.
What are euryhaline organisms?
Organisms that have a broad range of external environments they can survive in.
What is a perturbing solute?
Solutes that are most likely to affect protein function.
What is a compatible solute?
Solutes that have less affect on protein function.
What are counteracting solutes?
Two solutes may individually act as perturbing solutes but together act as compatible.
What affects cell volume?
Osmotic gradients affect cell volume and the ability of cells to transmit electrical signals. Water follows osmotic gradients.
What will cause an increase of cell volume?
A net input of particles into the cell that causes water to follow and swell the cell.
What causes a decrease of cell volume?
A net output of particles (active transport) causing water to follow and shrink the cell.
How do sea organisms maintain osmotic/ionic balance?
An increased amount of salt in the environment causes the organisms to implement ways to increase salt secretion and keep water.
How do fresh water organisms maintain osmotic/ionic balance?
These organisms bring in both water and particles (salt) and secrete both water and particles.
What is role of epithelial tissue in osmotic/ionic balance?
Tight junctions between cells allow separation of water and particles so that the body has to selectively move particles across membranes via different transporters. Lots of mitochondria present for active transport.
Where does adsorption and reabsorption occur across epithelial cells?
Via the luminal surface through the cell and then across the basolateral membrane.
Where does secretion/excretion occur across epithelial tissues?
Via the basolateral membrane through the cell and then out via the luminal surface.
How does the skin regulate aquaporins?
depending on the environment the integument will have an increased or decreased concentration of aquaporins.
What is the function of aquaporins?
Aquaporins increase the amount of water that can move in and of an organisms renal system. Decreased in desert environments and water environments.
What are strategies used by organisms to decrease water loss?
Hydrophobic substances (lipids, mucous, wax), cuticle, and stratum corneum.
What are cells found in fish gills that help import solutes?
Pavement cells that bring in sodium and chloride cells that bring in chloride. Important for keeping salt in fresh water envrionments.
What are salt glands?
A mechanism utilized by birds and reptiles in desert environments where they have high concentrations of salt and want to get rid of it. Salt moved from blood stream into lumen of secretory tubule via counter current flow.
What are rectal glands (elasmobranchs)?
A mechanism utilized by sharks to get rid of salt due to the sea water environment they are in. Active transport moves NaCl across the invagintaed basolateral membrane into the lumen of the cell and then out of luminal surface via channels.