1. Osmoregulation: The Basics
Osmoregulation/Renal Physiology
Osmoregulation: The Basics
Balancing salt concentration (solute concentration) in the blood.
Organisms can be osmoconformers
Fresh Water: Salt Water:
Organisms can be osmoregulators
( mosm/liter) (humans optimum is 300mosm/liter)
Water balance in cytoplasm…working for optimal conditions
Cytoplasm Interstitial Fluid Blood
(…and in kidney)
Excretory System: handles nitrogenous waste
Most organisms (vertebrates) have Kidneys to handle osmoregulation and excretion

2. Osmoregulation/Renal Physiology
THE LIFE AQUATIC: opposing osmotic forces
Marine Fishes: loss of water to hyperosmotic environment, balanced by drinking lots of water and active transport of Cl- out of body across gills. Produce very little urine.
Freshwater Fishes: gain water from a hypoosmotic environment. Must actively transport Cl- into body across gills to maintain electrolyte levels. Excrete large amounts of dilute urine.

3. Osmoregulation/Renal Physiology
THE LIFE TERRESTRIAL
The threat of desiccation is perhaps the largest regulatory problem confronting terrestrial plants and animals.
Human renal system works to maintain a blood osmolarity at 300 mosm/liter
Humans can die with 12% water loss
Dehydration is common: easy to see effects
All animals loose water through respiration. Why?
The human kidney (and kidneys of other terrestrial vertebrates) functions to remove nitrogenous waste, and also conserve water.
Human kidneys produce a hyperosmotic urine.

4. Osmoregulation/Renal Physiology
Nitrogenous Waste: A metabolic reality Why: Because animals often eat at 1° and 2° consumers…and they’re made of PROTEIN
Ammonia:
Fresh Water Fishes
Aquatic Invertebrates
Urea
produced in liver
Mammals, amphibians
Uric Acid
Insects, reptiles, birds

5. Cost/Benefits of different Nitrogenous Wastes
Osmoregulation/Renal Physiology
Cost/Benefits of different Nitrogenous Wastes
Toxicity
Dilution/Concentration
Energetic Costs

6. Osmoregulation/Renal Physiology
Cost/Benefits of different Nitrogenous Wastes Place ammonia, urea and uric on each of these spectra
Toxicity Hi Lo
Dilution/Concentration
[Hi]
[Lo]
Energetic Costs Lo Hi

7. Osmoregulation/Renal Physiology
Osmoregulation, carried out in the kidney is driven by the nephron: It has four essential functions.

8. Gross Anatomy of the Kidney
Osmoregulation/Renal Physiology
Gross Anatomy of the Kidney

9. The Low Down on Kidney Function
Osmoregulation/Renal Physiology
The Low Down on Kidney Function
Organs of filtration, absorption and secretion
Functional Unit is the NEPHRON (106/kidney)
Only 10 cm long, but contain 80 km of tubule length (~ 50 miles)
Only 1% of body mass, but receive 20% of resting cardiac output
Filter 1, ,000 L blood/day
Collect 180 L of filtrate
Produce 1.5 L of urine (on a good day)

10. Nephrons: Millions of Tubules & Blood Vessels /Kidney
Osmoregulation/Renal Physiology
Nephrons: Millions of Tubules & Blood Vessels /Kidney
Tubules
Blood Vessels

11. A closer look at the Nephron
Osmoregulation/Renal Physiology
A closer look at the Nephron
(look at how active transport of NaCl drives passive reabsorption
“water chases the solutes”)
ADH increases the
Permiability of water
Across the collecting
Duct. When ADH is
Blocked (by caffeine)
You need to urinate
more often.

12. Descending Loop of Henle: Permeable to…
Osmoregulation/Renal Physiology
Descending Loop of Henle: Permeable to…
Transfer of Fluid from…

13. Ascending Loop of Henle Permeable to…
Osmoregulation/Renal Physiology
Ascending Loop of Henle Permeable to…

14. Descending Loop/ Ascending Loop/ Collecting Duct (permeable to…
Osmoregulation/Renal Physiology
Descending Loop/ Ascending Loop/ Collecting Duct (permeable to…

15. Osmoregulation: Water Budgets
Osmoregulation/Renal Physiology
Osmoregulation: Water Budgets

16. Osmoregulation with ADH
Osmoregulation/Renal Physiology
Osmoregulation with ADH
Hypothalamus detects change in blood osmolarity
(> 300 mosom/L)
Release ADH, affects distal tubules and collecting ducts
How…
300 mosm/L

17. Osmoregulation with RAAS
Osmoregulation/Renal Physiology
Osmoregulation with RAAS
JGA = juxtaglomerular apparatus
Responds to drop in BP
JGA
Renin
Angiotensinogen
Angiotensin II
Adrenal Glands Arteries
Aldosterone Vasoconstriction

18. Short term and Long term response to stress
Osmoregulation/Renal Physiology
Short term and Long term response to stress

19. Renal Function is tied to…
Osmoregulation/Renal Physiology
Renal Function is tied to…
BLOOD.

20. Plasma: the liquid Matrix
Osmoregulation/Renal Physiology
Plasma: the liquid Matrix
Muy
Importante!

21. Osmoregulation/Renal Physiology
The Suspended Cells

22. The Physiology of Blood
Osmoregulation/Renal Physiology
The Physiology of Blood
RBCs and Hemoglobin…
RBC production regulated by erythropoeitin…
Luekocyte production: depends on what the body needs: associated with disease and infection, and inflammation
1st bullet :
2nd Bullet:
3rd Bullet:

23. Osmoregulation/Renal Physiology
Blood Clotting: An enzymatic cascade Begins with injury, ends with Fibrin net

24. Renal Function is tied to…
Osmoregulation/Renal Physiology
Renal Function is tied to…
EXCRETION (WASTE REMOVAL)

25. Physiological Connections
Osmoregulation/Renal Physiology
Physiological Connections
Air pressure at sea level = 760 mmHg (O2 comprises 21% of air, hence 160 mmHg)
Gases diffuse along a pressure gradient
Differences are called Partial Pressures
“Respiration happens passively by diffusion.”
--Ron Carlson

26. CO2 Transport & Exchange
Osmoregulation/Renal Physiology
CO2 +
H20
H2CO3
HCO3- + H+
CO2 Transport & Exchange

27. Oxygen Disassociation Curves
Osmoregulation/Renal Physiology
Oxygen Disassociation Curves
Notice the steepness of the curve. As PO2 drops, Hb “dumps“ O2

28. Osmoregulation/Renal Physiology
A few more terms
Osmoconformer:
Osmoregulator:
Stenohaline:
Euryhaline:

29. Invertebrate Excretory Systems
Osmoregulation/Renal Physiology
Invertebrate Excretory Systems

30. Marine Birds: Special Adaptations to xeric environment
Osmoregulation/Renal Physiology
Marine Birds: Special Adaptations to xeric environment