Question

a) identify structure a.
b) identify structure b. where does it drain?
this is an image of external eye structures, anterior view, with arrow a pointing to a structure located on the superolateral orbit and arrow b pointing to a tubular structure.

Explanation:

Part A:

Structure A is the lacrimal gland. The lacrimal gland is located in the superolateral (upper - outer) part of the orbit, which matches the description of the structure pointed to by arrow A. Its main function is to produce tears that lubricate the eye.

Part B:

Structure B is the nasolacrimal duct. The nasolacrimal duct is a tubular structure (as described in the image's caption) that is involved in the drainage of tears. The nasolacrimal duct drains tears from the lacrimal sac (which collects tears from the eye's surface) into the nasal cavity. Specifically, it empties into the inferior meatus of the nasal cavity. This is why when a person cries, they may experience a runny nose - the tears are draining into the nasal cavity through this duct.

Answer:

A) Structure A: Lacrimal Gland
B) Structure B: Nasolacrimal Duct; It drains into the inferior meatus of the nasal cavity (or more generally, the nasal cavity).