Renal Anatomy & Physiology in Exotic Species

Question 1

• What types of nitrogenous waste are produced by terrestrial organisms?

Answer 1

Urea & uric acid

Question 2

• What is significant about a fish’s renal anatomy?

Answer 2

No loop of Henle, no glomeruli in some species

Question 3

How do freshwater fish osmoregulate?

Answer 3

Natural water gain across gills, therefore high GFR and active NaCl uptake

Question 4

• How do saltwater fish osmoregulate?

Answer 4

Natural water loss across gills, therefore drink seawater to replace, excrete NaCl

Question 5

• What nephron types are present in birds?

Answer 5

Reptile type – no loop of Henle, cortex only

Mammalian type – loop of Henle, cortex & medulla

Question 6

• What is significant about a snake’s bladder?

Answer 6

No bladder, urine stored in distal colon or flared ends of each ureter

Question 7

• What is the function of the large eosinophilic granules secreted into the lumen by some male squamates?

Answer 7

Separate urine/semen copulation

Question 8

• Why is reptile urine not reflective of renal function?

Answer 8

Ions (active transport) and water (passive transport) are resorbed across colon wall

Question 9

• What happens when the renal portal valve is opened in birds (and possibly reptiles)?

Answer 9

Blood bypasses the kidneys

Question 10

• What are the reptile renal adaptations to conserve water?

Answer 10

Few nephrons, lower GFR, cease GF in times of stress, cloacal absorption of water

Question 11

• What is the function of the avian salt glands?

Answer 11

Excrete NaCl, stimulated by increased plasma osmotic concentration