osmoregulation definition and function Transport epithelia in osmoregulation

2. Transport epithelia
in osmoregulation

3. Presented By:
Zainab Imran
Roll no:
2016-1911
Program:
M.S.Ed
Submitted to:
Mam Afshaan Mumtaz

4. Osmoregulation
– The maintenance of constant osmotic pressure in the fluids of an organism by
the control of water and salt concentrations.
– Osmoregulation is the active regulation of the osmotic pressure of
an organism's body fluids, to maintain the homeostasis of the organism's water
content

5. – The ultimate function of osmoregulation is to maintain the composition of
cellular contents
– But most animals do this indirectly by managing the internal body fluid that
bathes the cell.
– In Open circulatory system, the fluid is hemolymph that bathes the cell.
– In closed circulatory system, the interstitial fluid is blood that circulate solutes within
the body.
– Maintaining the composition of fluid depends upon :
– cell structure that regulate solute movement to vertebrate kidney

6. Transport Epithelia in Osmoregulation
– In most animals, Osmotic regulation and metabolic waste disposal relay on
Transport epithelium
– Transport Epithelium is layer of specialized epithelial cells that regulate solute
movement.
– moves specific solute in controlled amount in specific direction.
– Arranged into complex tubular network with extensive surface area.
– Some Transport epithelium face outside environment directly while other lines
channel connected to outside on body surface.

8. How do Seabirds eliminate excess salt from
their bodies
– Questioning this answer, Knut Schmidt- Nielsen and colleagues carried out a
simple informative experiment.
– They gave marine birds seawater only to drink. However small amount of salt
bird consumed appeared in their urine. Remainder concentrated in clear fluid
dripping from the tip of birds beak.
– Where did this salty fluid come from?

10. – The researcher focused their attention on nasal glands in head of all birds,
Schmidt-Nielsen hypothesized that nasal glands function in salt elimination.
– To test this , researchers inserted a thin tube through the duct leading to nasal
glands and withdrew fluid.
Result:
– The fluid drawn from nasal glands were nearly pure NaCl solution
Conclusion
– Marine birds utilize their nasal glands to eliminate excess salt from body. It is
the organ that make life possible for such species.

11. – In removing excess NaCl from blood, nasal glands relies on Counter-current
exchange.
– In albatross’s nasal gland nasal glands , the net result is secretion of fluid much
saltier than ocean.
– Humans who drink given volume of sea water must use a greater volume of
water to excrete the salt load.
– Transport epithelia functions in maintaining water balance as well as in disposal
of metabolic wastes in earthworms and insects secretory system as well as in
vertebrate kidney.

12. Animal’s Nitrogenous wastes reflects its phylogeny
and habitat
– The type and quantity of waste product may affects its water balance
– Amongst most important wastes are Protein and nucleic acid breakdown prodcts.
– Ammonia
– Diffuses across the body surface or at gills
– Urea
– Ammonia converted to urea in the liver, concentrated in the kidneys
– Uric acid
– Largely insoluble in water
– Secreted as a paste with minimum water loss

13. Any Question?