By which part of the vasa recta NaCl is returned to the medullary interstitium?

1

(a)

NaCl is returned to the medullary interstitium by the ascending part of the vasa recta by reabsorption mechanism.

In which part of the excretory system of mammals you can first use the term urine?

1

(a)

Collecting duct.

Give the name of the nitrogenous waste which is produced in birds.In what form is it eliminated from the body?What is the advantage of this type of excretion?

1

(a)

Birds excrete uric acid in the form of pellet or paste (semi-solid form). It helps is conservation of water.

Explain the function of vasa recta?

1

(a)

The vasa recta helps in reabsorption of important nutrients from medullary interstitial tissues.

Name the pigment that causes pale yellow colour of urine.

1

(a)

Urochrome pigment gives yellow colour to urine.