Unit 3: Excretory Flashcards
Osmosis
Diffusion of water through semipermeable membrane. Water moves from hypotonic to hypertonic until isotonic.
Hypertonic, Hypotonic, Isotonic
Hypertonic- more solute, less water
Hypotonic- less solute, more water
Isotonic- equilibrium
Osmoconformers
Isotonic to environment, no osmosis
Osmoregulators
Use negative feedback to maintain osmolarity
Saltwater fish
Hypotonic, drinks seawater and gills use active transport to remove salt
Freshwater fish
Hypertonic, gills use active transport to absorb salt
Stenohaline
Can’t tolerate fluctuations in osmolarity
Euryhaline
Can survive large fluctuations in osmolarity
Terrestrial organism water conservation adaptations
Urine regulation, waterproof structures (scales, keratinized skin), drink water, water-rich food, nocturnal, moist environment, electron transport chain
Ammonia (nitrogenous waste)
High toxicity, high water loss, simple molecule, low energy cost (freshwater)
Urea (nitrogenous waste)
Less toxic, less water loss, more complex, high energy cost (saltwater, mammals, amphibians)
Uric Acid (nitrogenous waste)
Low toxicity, no water loss, most complex, high energy cost (desert animals, birds, reptiles, insects)
Excretory system functions
Filtration, reabsorption, secretion, excretion
Protonephridia (excretory systems)
Flatworms
Metanephridia (excretory systems)
Earthworms
Malpighian Tubes (excretory systems)
Arthropods
Kidneys (excretory systems)
Vertebrates
Proximal Tubule (nephron)
Beginning of excretion and reclamation, pH regulation
Descending Loop of Henle (nephron)
Reabsorption of water (aquaporins)
Ascending Loop of Henle (nephron)
Reclamation of NaCl
Distal Tubule (nephron)
Balancing Na/K, pH
Collection Duct (nephron)
Processes filtrate into urine and excretes through renal pelvis
