water and ion balance Flashcards
What are the three homeostatic processes?
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Osmotic regulation
- osmotic pressure of body fluid
Ionic regulation - concentrations of specific ions
Nitrogen excretion
-excretion of end-products of protein metabolism
Ionic and osmotic challenges
Marine environments
animals tend to gain salts and lose water
Ionic and osmotic challenges
freshwater environments
animals tend to lose salt and gain waer
Ionic and osmotic challenges
terrestrial environments
animals tend to lose water
Ionic and osmotic challenges
what must animals that move between environments do?
be able to alter their homeostatic mechanisms
Osmotic regulation
strategies to meet osmotic challenges?
what are the two types?
osmoconformer
osmoregulator
Osmotic regulation
strategies to meet osmotic challenges?
osmoconformer
internal and external osmolarity similar
for example marine invertebrates
Osmotic regulation
strategies to meet osmotic challenges?
osmoregulator
osmolarity constant regardless of external environment
example more vertebrates
Ion regulation
strategies to meet ionic challanges
two types
ionoconformer
ionregulator
Ion regulation
strategies to meet ionic challanges
ionoconformer
exert little control over ion profile within the extracellular space
exclusively found in marine animals for example many invertebrates
Ion regulation
strategies to meet ionic challanges
ionregulators
control ion profile of extracellular space
for example most vertebrates
More comples than a cluster of cells then your body will have fluid compartments
Total body water=
water inside cells =
water outside cell=
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TBW - 50-70% of BW
ICF-2/3
ECF-1/3
Cell volume
cells transport solutes in and out of extracellular fluid to control what?
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cell volume
water follows solutes by osmosis
Animals regulate composition of the ECF to provide cells with what?
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provide cells with external solution that allows them to maintain appropriate cell volume
cell volume regulation
a change in cell volume can arise in response to what?
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environmental osmotic stress
this could be deteimental beacuse cell swelling from severely hypotonic environment can cause cells to explode
cell volume regulation
cells control their volume how?
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by regulating solutes across the plasma membrane
cell volume regulation
regulatory volume increase
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importing ions, influx of water
cell volume regulation
regulatory volume decrease
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exporting ions, efflux of water
Epithelial tissue does what?
forms boundary between animal and environment
Epithelial tissue
external surface
skin
Epithelial tissue
internalized surface
lumen of digestive, excretory system, kidney
Epithelial tissue have what physiological function?
respiration, digestion, and ion and waer regulation
integument: Osmotic barrier
animal change flux of water across bodysurface by mediating waht?
permeability of the integument
integument: Osmotic barrier
What do aquaporin proteins do?
proteins increase water permeability 100-fold, so reduce number of aquaporins in skin
integument: Osmotic barrier
typically animals need to reduce water flux how do they do this?
cover external surfaces with layers of hydrophobic molecules
sucha as:
mucus
conified stratum corneum with keratin
hydrophobic matrix or keratin and lipids- hydrophobic barrier
cuticle with chitin (arthropods)
epithelial tissue properties for ion movement
epithelia tissue also plays a important role in what?
transport of ions (digestive tract, kidneys, gills)
epithelial tissue properties for ion movement
four freatures of transport epithelia?
asymmetrical distribution of membrane transport
-solutes selectivelu transport across membrane
cells interconnected to form impermeable sheet of tissue
-little leakage between cells
high cell diversity within tissue
abundant mitochondria
-large energy (ATP) supply
Solute movement
what are the two main routes of transport that epithelial cells use?
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trancellular transport
paracellular transport
Solute movement
what is transcellular transport?
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movement through the cell across membranes
Solute movement
paracellular transport?
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movement between cells
leaky vs. tight epithelia
Solute movement
five types of transporters
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- Na/Katpase-HUGE consumer of ATP
- other ATPase
- Ion channels (Cl,K,Na)
- Electroneutral cotransporters
- electroneutral exchangers
Epithelial cells in fish gills
what are fish gills composed of?
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Cholride cells (PNA+) -large mitochondria rich cells
Pavement cells
-some mitochondria rich (PNA-)
-some mitochondria poor (PNA-)
transport likely carried out by mitochondria-rich cells
Digestive epithelia
water and salts from drinking and foood is transported across what?
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digestive epithelium
transcellular and paracellular transport involved
absorbed water and salts enter blood
some waste products excreted ( From liver via bile)
who is the smartest, most motivated, best looking Bio 365 student
you are :)
GOODLUCK KEEP GOING
