osmoregulation and excretory systems Flashcards
Homeostasis
a self-regulating process by which a living organism can maintain its internal stability while adjusting to changing external conditions
Osmoconformer definition
osmotic pressure of body fluids and cells = surrounding solution
Osmoregulator definition
osmotic pressure of body fluids and cells is homeostatically regulated despite external changes in the environment
isotonic
outside and inside cell concentration and pressure are equal
hypertonic
external solution has higher solute and lower water concentration = higher osmotic pressure, meaning the cells shrinks (plasmolysis)
hypotonic
external solution has a low solute concentration, high water concentration compared to cell = cells will swell and burst (cytolysis)
simple diffusion
channel transported molecules or lipophilic uncharged molecules can pass through the lipid bilayer
Facilitated diffusion
requires no energy takes advantage of the concentration gradient, uni-one way, sym- simultaneously transports 2 molecules, Anti- possible for 2 way diffusion(uniport, Symport, Antiport)
features and preferences of osmoconformers
sensitivity to salinity fluctuation, cells shrink or swell, no regulation of osmolytes, stable environments
Stenohaline
an organism that cannot tolerate a wide range of salinities
Euryhaline
an organism that can tolerate a wide range of salinities
Hydromineral regulation
the active regulation of osmotic pressure so that homeostasis is maintained
what do Excretory systems do?
help maintain homeostasis by regulating concentrations of body fluids, removal of waste products
Principal waste products of animal metabolism
water - carbon - nitrogenous wastes (Ammonia, urea, uric acid)
Ammonia NH4+
water soluble, excreted by most aquatic animals via the gills, toxic
Urea CH4N2O
less toxic, less water soluble, removes 2N per molecule
Uric Acid C5H4N4O3
even less toxic, water soluble, end product of amino acid and purine metabolism, energy expensive, missing in mammals
Excretory organs of invertebrates
Protonephridia, Metanephridia, Malpighian tubes
Protonephridia
flat worms
Metanephridia
annelids
Malpighian tubes in invertebrates
Kidneys in vertebrates
kidneys
excretion and osmoregulation, vital in maintaining homeostasis, produce urine
Urine formation
Filtration of plasma, reabsorption of needed materials, secretion of potassium and hydrogen ions
urine volume is regulated by what
regulated by antidiuretic hormone (ADH)
ADH
released by pituitary gland in response to increased osmotic concentration of blood, ADH increased permeability of collecting ducts to water, as result more water reabsorbed