Presentation on theme: "Osmoregulation = keeping water and salt balanced in the body Question 1: why is this important – Come up with three reasons Question 2: What water and."— Presentation transcript:
Osmoregulation = keeping water and salt balanced in the body Question 1: why is this important – Come up with three reasons Question 2: What water and salt problems do the following organisms face? – Freshwater fish – Marine fish – Marine birds – Marine mammals Question 3: How might each group solve those problems?
Marine teleosts: Osmoregulators (hyposmotic to environment) Problems? Solutions?
How do they get rid of huge salt load? Marine reptiles and birds… seawater Salt glands! Nasal fluid urine
Salt glands salt is excreted from the gland to outside the body more concentrated than sea water! mechanism is same in marine reptiles -but salt gland is in different places Na+ mOsm seawater470 sea snake620 sea turtle690 Marine Iguana1000-1400 gull600-900 cormorant500-600 petrel900-1100
How do mammals make concentrated urine? Each nephron has a loop of Henle: nephron loop of Henle
Marine Mammals 1. Long loop of henle in the kidney --concentrated urine --less water lost with waste 2. Diet --carnivores, eating mostly vertebrates --vertebrates have lower osmolarity 3. Absence of sweat glands Several Adaptations:
Terrestrial summary Water in: – Food and drink – Metabolic water Water out: – excretion – Evaporative water loss Adaptations in the desert? – Extended loop of henle – Reduced evaporative water loss (gain in camel nose) – High dehydration tolerance