Acountercurrent mechanism is in the
a. afferent and efferent arterioles
b. glomerulus and bowman's capsule
c. proximal and distal tubules
d. ascending and descending limbs of the loop of henle

Complete the following sentence that describe the alimentary canal and its walls: the is composed mostly of connective tissue, nerves, and vessels, which to nourish surrounding tissues.

What is crystallographic data processing and structure determination? what are the physical infrastructures of x-ray crystallographic structural biology? who can tell me detailed information? any would be appreciated. in advance!

Describe the effects and potential risks associated with pica. include lead poisoning in the discussion.