Chapter 16 Solutions — Excretory Products and Their Elimination

Exercises

1. 1.
   Define Glomerular Filtration Rate (GFR)
2. 2.
   Explain the autoregulatory mechanism of GFR.
3. 3.
   Indicate whether the following statements are true or false :

   • (a) Micturition is carried out by a reflex.
   • (b) ADH helps in water elimination, making the urine hypotonic.
   • (c) Protein-free fluid is filtered from blood plasma into the Bowman's capsule.
   • (d) Henle's loop plays an important role in concentrating the urine.
   • (e) Glucose is actively reabsorbed in the proximal convoluted tubule.
4. 4.
   Give a brief account of the counter current mechanism.
5. 5.
   Describe the role of liver, lungs and skin in excretion.
6. 6.
   Explain micturition.
7. 7.
   Match the items of column I with those of column II : Column I Column II

   • (a) Ammonotelism
   • (i) Birds
   • (b) Bowman's capsule
   • (ii) Water reabsorption
   • (c) Micturition
   • (iii) Bony fish
   • (d) Uricotelism
   • (iv) Urinary bladder
   • (d) ADH
   • (v) Renal tubule
8. 8.
   What is meant by the term osmoregulation?
9. 9.
   Terrestrial animals are generally either ureotelic or uricotelic, not ammonotelic, why ?
10. 10.
    What is the significance of juxta glomerular apparatus (JGA) in kidney function?
11. 11.
    Name the following:

    • (a) A chordate animal having flame cells as excretory structures
    • (b) Cortical portions projecting between the medullary pyramids in the human kidney
    • (c) A loop of capillary running parallel to the Henle's loop.
12. 12.
    Fill in the gaps :

    • (a) Ascending limb of Henle's loop is _______ to water whereas the descending limb is _______ to it.
    • (b) Reabsorption of water from distal parts of the tubules is facilitated by hormone _______.
    • (c) Dialysis fluid contain all the constituents as in plasma except _______.
    • (d) A healthy adult human excretes (on an average) _______ gm of urea/day.