The wall of the urinary bladder in humans shows a thick layer of smooth muscle called . . . . . . .

Which blood vessel contains the least amount of urea?

The $pH$ value of human urine is:

What is the difference between an afferent arteriole and an efferent arteriole?

Complete the analogy.
$Renal \text{ } pelvis : \text{ } ureter :: \text{ } Renal \text{ } cortex : \text{ } . . . . . . $

$A:$ The inner wall of Bowman's capsule is lined with specialized cells called podocytes,which have a number of projections.
$R:$ These projections increase the surface area for absorption.