Animal Water And Electrolyte Balance

1. Identify the reasons why water and electrolyte homeostasis are important in animals.

Animals can survive without regulating their water and electrolyte levels

If no Electrolytes...1. muscle spasms2. confusion3. system of balance4. heart5. tired6. paralysis
If no Water..2. keep ion concentration at constant rate

Water and electrolyte balance only affects animals' appearance

Water and electrolytes are not important in animal homeostasis

2. Differentiate between osmoconformers and osmoregulators.

Osmoregulators are most commonly found in marine invertebrates.

Osmoregulators do not regulate the composition of solutes inside their cells.

Osmoconformers:-they do not actively regulate the osmolarity of their tissues-they do regulate the composition of their solutes inside their cells (most marine invertebrates)
Osmoregulators:-actively regulate osmolarity inside their bodies to achieve homeostasis(marine fish)

Osmoconformers actively regulate osmolarity inside their bodies.

Osmoconformers and osmoregulators have distinct mechanisms for maintaining osmotic balance in their bodies, with osmoconformers adjusting to external salinity and osmoregulators actively regulating their internal osmolarity to ensure homeostasis.

Explanation

Osmoconformers and osmoregulators have distinct mechanisms for maintaining osmotic balance in their bodies, with osmoconformers adjusting to external salinity and osmoregulators actively regulating their internal osmolarity to ensure homeostasis.

3. Compare and contrast how marine, freshwater, and anadromous fishes osmoregulate.

Marine Fish (gain salt, lose water)-replace lost water by drinking large quantities of sea water-bring in excess electrolytes-ion/solutes diffuse from seawater into tissues-rid excess electrolytes by secreting urine-almost all gas exchange across gills
Freshwater Fish (lose salt, gain water--- do not drink water)-exposed to a concentration gradient 100 to 1000 times greater than that faced by marine fish-gill epithelium--hypertonic relative to water (gain water via osmosis)-water moves from epithelium to adjacent tissues putting them under osmotic stress-if freshwater does not get rid of incoming water, its cells eventually burst-secrete large amounts of water in their urine
Anadromous Fish (part marine, part freshwater)-when in the ocean: transport ions out of gills into the water-when in freshwater- (process controlled by hormones)-- transport ions into blood across gills

Marine Fish (lose salt, gain water)-exposed to a concentration gradient 100 to 1000 times greater than that faced by freshwater fish-gill epithelium--hypotonic relative to water (lose water via osmosis)-water moves from adjacent tissues to epithelium, leading to dehydration.

Anadromous Fish (freshwater only)-secrete large amounts of salt in their urine to maintain osmotic balance-regulate water intake by drinking saltwater in small quantities to balance electrolytes-between marine and freshwater environments, they experience minimal osmotic changes.

Freshwater Fish (gain salt, lose water)--dive into saltwater sources to intake excess electrolytes-ion/solutes diffuse into freshwater habitats through their skin-rid excess electrolytes by active secretion through gill epithelium-almost all gas exchange occurs through skin.

4. Identify the three main types of nitrogenous wastes produced by animals. Which animals produce which wastes?

Acetic Acid (Insects) - moderate expense to make - slightly toxic - requires some water to excrete

Creatinine (Humans) - toxic - requires moderate amount of water to excrete

Formic Acid (Plants) - cheap energetically to produce - non-toxic - easily soluble in water

Ammonia (Fish)-toxic-cheap energetically to produce-at high concentrations it raises the pH-needs a lot of water to be excreted
Urea (Mammals)-more expense to make -less toxic-requires less water to excrete
Uric Acid (Birds, Reptiles)-very expensive to make-not toxic-insoluble in water

5. What are the costs and benefits of each type of waste? What is the trade-off between production of uric acid and urea?

Uric acid is more expensive to make than urea and toxic, but it is easily soluble in water.

Uric acid is the most toxic waste product, but it is easily excreted due to its solubility in water.

Urea is less expensive to make than uric acid, but it requires large amounts of water to excrete.

Uric acid is less expensive to make than urea and not toxic, but it is insoluble in water. Urea, although more expensive and less toxic requires little amounts of water to excrete.---cope with dry habitats: conservation of water

The correct answer highlights the key differences between uric acid and urea, especially in terms of cost, toxicity, and solubility. It also mentions the trade-off in water conservation based on the type of waste produced.

Explanation

The correct answer highlights the key differences between uric acid and urea, especially in terms of cost, toxicity, and solubility. It also mentions the trade-off in water conservation based on the type of waste produced.

6. What is the unique osmoregulatory mechanism of sharks?

Gill cells actively pump out excess salt ions

Aquaporins in gills facilitate entry of water into the blood

Sharks absorb water through their skin to maintain osmotic balance

Rectal Gland (secretes concentrated salt solution)1. Na+/K+ ATPase pumps Na+ out of cell and K+ into cell-creates an electrochemical gradient favoring diffusion of Na+ into cell and K+ out of cell
2. Na+/Cl-/K+ co-transporter is powered by the gradient favoring Na+ diffusion-brings these three ions from the extracellular fluid into the epithelial cells
3. K+ diffuses out through channels -Cl- diffuses into lumen along its concentration and charge gradients
4. Na+ diffuses into lumen along its concentration and charge gradients.

Sharks use a rectal gland to secrete a concentrated salt solution, different from the three incorrect options provided.

Explanation

Sharks use a rectal gland to secrete a concentrated salt solution, different from the three incorrect options provided.

7. How do Malpighian tubules function in insect osmoregulation?

1. Malpighian tubules regulate the body temperature of insects.

3. Malpighian tubules play a role in the sensory perception of insects.

2. Malpighian tubules are involved in the production of digestive enzymes in insects.

1. isotonic pre-urine that forms in Malpighian tubules empties into the hindgut
2. In the hindgut the primary driving forces for reabsorption of electrolytes and water are chloride pumps in the apical membrane and Na+/K+ ATPases in the basolateral membrane

-formation of pre-urine is not selective-reabsorption is high selective and highly regulated

8. Identify the major parts of the mammalian nephron and list the substances reabsorbed at each part.

1. Cortex 2. Medulla 3. Renal pelvis 4. Ureter

1. Glomerulus (has slits--only allow small things through)2. Bowman's capsule----- filters blood: to create a pre-urine comprising water, electrolytes and other small substances----25% of water and solutes present in blood is removed
3. Proximal convoluted tubule-recycling center-reabsorption-selectively retrieves small substances that are valuable-almost everything absorbed here
3. Descending limb--highly permeable to water
4. Loop of Henle-countercurrent flow of fluid-osmotic gradient stimulates water and ion flow that in turn maintains an osmotic gradient-creation/maintenance of a strong gradient allows for concentrated urine
5. Ascending Limb-highly permeable to Na+ and Cl-
6. Distal convoluted tubule-Electrolytes and water are reabsorbed-Na+, Cl-, water are either excreted or reabsorbed -depends on hydration -under hormonal control7. Collecting Duct -well hydrated impermeable to water-Electrolytes and water are reabsorbed-Na+, Cl-, water are either excreted or reabsorbed -depends on hydration -under hormonal control

The major parts of the mammalian nephron are specific structural components involved in the filtration and reabsorption of substances in the kidney. Each part plays a crucial role in the overall function of the nephron.

Explanation

The major parts of the mammalian nephron are specific structural components involved in the filtration and reabsorption of substances in the kidney. Each part plays a crucial role in the overall function of the nephron.

9. Why is the loop of Henle crucial to the ability of the mammalian kidney to produce concentrated (high osmolarity) urine?

The loop of Henle removes excess glucose from the filtrate.

The loop of Henle is responsible for filtering out nitrogenous wastes.

The loop of Henle controls the pH balance of urine.

Osmotic gradient would disappear if filtrate ran the same direction.
- created gradient by reabsorbing water/electrolytes differentially along its U shaped length
-gradient allows kidney to concentrate urine

The loop of Henle creates a gradient by reabsorbing water and electrolytes differentially along its U shaped length, which allows the kidney to concentrate urine.

Explanation

The loop of Henle creates a gradient by reabsorbing water and electrolytes differentially along its U shaped length, which allows the kidney to concentrate urine.

10. Describe the role of antidiuretic hormone in the formation of concentrated urine in mammals.

Antidiuretic hormone stimulates urine production in mammals.

Antidiuretic hormone is released from the kidneys in response to dehydration.

Antidiuretic hormone decreases the permeability of aquaporins in epithelial cells of the collecting duct.

Antidiuretic: -released from the brain if an individual is dehydrated-inhibition of urine production-retains water- when it arrives at epithelia cells lining the collecting duct it triggers aquaporins -cells become more permeable to water-water leaves the collecting duct passively