Osmoregulation and excretion

Why are osmoregulation and solute balance integral to proper cell function?

Osmoregulation and solute balance are crucial for maintaining proper cellular function by ensuring that cells do not lose or gain excessive water, which can lead to damage or improper function. This balance ensures the correct environment for biochemical reactions.

What is osmosis

Osmosis is the movement of water molecules across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Define osmoregulation.

Osmoregulation is the process by which an organism regulates the concentration of water and solutes in its body to maintain homeostasis.

What is osmotic concentration?

Osmotic concentration refers to the concentration of solute particles in a solution, influencing water movement and osmosis.

Define hypoosmotic and hyperosmotic

• Hypoosmotic: A solution with a lower concentration of solutes compared to another solution.

• Hyperosmotic: A solution with a higher concentration of solutes compared to another solution.

How do nitrogenous waste types vary in different animals?

• Ammonia: Excreted by aquatic animals (toxic, but highly soluble in water).

• Urea: Excreted by mammals, amphibians, and sharks (less toxic, requires energy to convert from ammonia).

• Uric acid: Excreted by reptiles, birds, and insects (less toxic, requires more energy but conserves water).

What is the difference between osmoregulators and osmoconformers?

• Osmoregulators actively regulate their internal solute concentration, regardless of the external environment.

• Osmoconformers allow their internal solute concentration to match the external environment.

Predict the response of osmoregulators to different solute concentrations.

Osmoregulators adjust their internal water and solute concentration to maintain homeostasis, either by excreting excess water or conserving it, depending on whether they are in hypoosmotic or hyperosmotic environments.

How do osmoregulatory challenges differ between freshwater and seawater animals?

• Freshwater animals: They face a challenge of gaining excess water, so they must actively expel water and conserve solutes.

• Seawater animals: They must conserve water and excrete excess salts.

What are the basic principles of renal function?

• Filtration: The process of filtering blood to remove waste products.

• Reabsorption: The process of reclaiming necessary substances (like water and nutrients) from the filtrate back into the blood.

• Secretion: The active transport of additional waste into the filtrate.

• Excretion: The removal of waste from the body through urine.

Label the structure of the mammalian kidney and nephron, and describe their functions.

• Mammalian kidney: Contains structures like the cortex, medulla, and renal pelvis. It filters blood, removes waste, and regulates water balance.

• Nephron: The functional unit of the kidney, responsible for filtering blood, reabsorbing water and solutes, and secreting waste into the urine.

Describe the passage of primary urine through the nephron and the changes in its volume and concentration.

• Filtration: Blood enters the glomerulus, where primary urine is formed.

• Reabsorption: In the proximal convoluted tubule, most water and solutes (glucose, ions) are reabsorbed into the blood.

How is water balance regulated by hormones? Provide an example.

water balance is regulated by hormones like antidiuretic hormone (ADH), which promotes water reabsorption in the kidneys, reducing urine output to conserve water.