Osmoregulation & Ionoregulation Flashcards
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Osmoregulation
-Regarding the water content of an organism
ionoregulation
Regulating the ionic composition of an organism
Animals can be either
______________
or
______________
A. Osmo conformers
(Body fluid concentration changes as the environment changes)
B. Osmo regulators
(Body fluid concentrations remains constant in spite of a changing environment)
Obligatory Osmotic Exchanges
IN:
- Transepithelial diffusion
- Ingestion
- Production of metabolic water
- Water Vapour
Obligatory Osmotic Exchanges
OUT:
- Defecation
- Urine
- Evaporation through respiration
- Trans cut aneous diffusion
Factors affecting obligatory osmotic exchanges
- Transepithelial obligatory osmotic exchanges
- Permeability of the integument
- Surface area to volume ratio
- Feeding
- Temperature, exercise, respiration
- Metabolic rate
Osmotic exchange
- Water passes easily through _______ ________
- Water moves from an environment of ___ ______ concentration to one of ____ ______ concentration (osmosis)
- Osmotic water movement creates osmotic _______
Osmotic exchange
- Water passes easily through biological membranes
- Water moves from an environment of low solute concentration to one of high solute concentration (osmosis)
- Osmotic water movement creates osmotic pressure
Freshwater teleost fish
- High concentration of salt inside the body
- None on the outside of the body so ions trying to move down the concentration gradient from the body of the animal out into the environment.
- Water is trying to move the opposite way by osmosis (into the animal)
Animals copes with this by:
- Reduced permeability
- Fresh water fish do not drink
- All the water requires is absorbed through body
- Fish is urinating dilute liquid all the time (retains salt)
- Ions diffusing out of body into external enviro, it counteracts that by the gills actively transporting ions against concentration gradient from the envro back into the body.
Marine teleost fish e.g snapper
- Body is same concentration as fw fish but external environment is much more salty (higher salt/lower water)
- Snapper is gaining ions by diffusion as Snapper body is the lower concentration gradient
- Water is going the opposite way, trout water diffusing in to the body by osmosis, now in snapper water is diffusing out of the body down the concentration gradient.
- Snapper does drink as it loses water by osmosis (needs it back)
- Snapper produces very small amounts of highly concentrated urine to reduce water loss
- Ions are diffusing into the body of the Snapper so the fish now pumps them out actively across the gill.
Marine elasmobranch
- No tendency for water to move in or out of the body as the primitive blood of the shark is similar to the sea water
- Ions are diffusing into the body as Shark has low concentration of ions in blood like the marine teleost fish.
- Shark drinks sea water, produces small amounts of hypertonic urine.
- Rectal gland called pumps salt out of the body.
- Sharks retain urea (osmolites)
What hormones do diadromous fish use during migration between fresh and salt water?
The hormone ________ is involved in adaptation to seawater
The hormone _________ is involved in adaptation to freshwater
The hormone cortisol is involved in adaptation to seawater
(vertebrate stress hormone)
The hormone prolactin is involved in adaptation to freshwater
(Milk hormone stimulates lactation)
Marine reptiles and birds produce _______ _______ from salt glands.
hypertonic secretions
Lingual salt glands of the esturine crocodile are located where?
On the surface of the crocodiles tounge
