BIOS 100 Excretory System

  1. What are the core concepts of excretory system?
    • Differenthabitats present different challenges to the water and electrolyte balance ofthe animals that inhabit them.
    • The Sodium-Potassium pump represents a common mechanism in maintenance of water and electrolyte balance.
    • The ability to form a concentrated urine is critical to the success of animals in terrestrial habitats.
  2. What are the main function of excretory system?
    • Water conservation
    • Reduction of Osmotic Stress and Osmoregulation
    • Removal of Nitrogenous Wastes from the Body
    • Regulation of Blood Volume and Concentration
  3. What's osmoregulation?
    the ability to counteract osmotic stress and maintain homeostasis with respect to water and electrolyte balance.
  4. Deaminationof amino acids generates the toxic compound ammonia. Terrestrial organisms convert ammonia to a less toxic compound for excretion. What is this waste and what's it's function?
    Urea is the primary nitrogenous waste of mammals. It is more water-soluble than uric acid, so more water is required to excrete this form, but its synthesis requires less energy.
  5. How does regulation of blood volume occur?
    –The total volume of blood plasma and interstitial fluid is regulated by the degree of filtration and reabsorption in the kidney
  6. What are the two models for waste removal?
    • Model 1 – remove specific wastes, leaving all the essential chemicals and water behind
    • Model 2 – Dump most everything out and reabsorb all necessary fluids and chemicals.  Everything left behind is waste
  7. What does mammalian kidney consists of?
    Cortex and an inner medulla (as one progresses inward from cortex to inner medulla, the concentration of solutes increases from about 300 mosm/L to 1200 mosm/L. )
  8. Th functional unit of the kidney is nephron. What does it consists of?
    • glomerulus, situated in cortex of kidney
    • proximal tubule
    • a long U-shaped tubule (loop of Henle) extending into the medulla of the kidney
    • distal tubule
    • collecting duct
  9. There are four phases of Kidney functions. What are they?
    • Phase I: Filtration in Bowman's Capsule
    • Phase II:Reabsorption in the proximal Tubule
    • Phase III: Creation of an Osmotic Gradient in the Loop of Henle
    • Phase IV: Regulating Water and Electrolyte Balance in the Distal Tubule and the Collecting Duct
Card Set
BIOS 100 Excretory System
BIOS 100 Excretory System