Renal System - Osmoregulation Flashcards
Role of ADH + collecting duct (and DCT)
1)Osmoreceptor in hypothalamus detect water level too low in cerebral spinal fluid (or blood) shrivel up + send signal to pp gland
2)send signal to posterior pituitary gland - release ADH to collecting duct + DCT via blood
3)Activates aquaporin - water diffuse out (cytoplasm water potential already low)
4)more permeable to water = more water reabsorbed = urine more concentrated
5)happen until water level get back to normal
6)if water level too high less ADH released = lose more water
DCT also reabsorb ions
Different nitrogenous waste by different animal
Ammonia - fish
Adv- little energy to produce, highly soluble
Disadv - highly toxic, need high volume water to dilute to be less toxic (lots of water around for fish), algae bloom from N, very toxic in high concentrations
Urea - mammal
Adv- less toxic than ammonia, less water needed for dilution , can be stored
Disadv- more energy need than ammonia, not non-toxic still need removal, need water for dilution
Uric acid - dry places or airborne (bird)
Adv- not toxic, no water needed to dilute (insoluble), less weight for flying
Disadv- need lot of energy to produce
Kidney of different animal
Water - short loop of Henle, does not extend far into medulla, no need to conserve water
(Cortical nephron) <- has many
Normal - loops of Henle into medulla, longer than water
Humans have balance of both nephrons
Dry - loops of Henle fully into medulla, longer loop of Henle
(Juxtamedullary nephron) <- has many
Behavioural adaption for desert animal for water
-get mostly metabolic water (reactions like respiration)
-Nocturnal - cool = sweat less
-Instinct = burrow underground during day avoid predator
-sleep during day = less metabolism = less heat as waste energy = maintain water
Negative effect of alcohol + caffeine
Both diuretic
-alcohol: inhibit ADH production
-caffeine: competitively inhibit (antagonist) receptor ADH bind to in collecting duct
