Final answer:
Brow ridges are bony structures contributing to facial contour, more prominent in males, and muscle lines refer to various facial muscles like the buccinator muscle and corrugator supercilia, which are important for expressions and actions like chewing.
Step-by-step explanation:
The student has asked about the prominence of brow ridges or muscle lines. The brow ridges are bony structures located just behind the eyebrows, formed by the frontal bone in the skull. They are more pronounced in males and can be felt above the supraorbital margin, which also houses the supraorbital foramen for sensory nerves. Furthermore, the buccinator muscle composes a large part of the facial structure and aids in actions such as whistling, blowing, and chewing. The corrugator supercilia is a small facial muscle that is the prime mover of the eyebrows, involved in facial expressions like surprise and frowning.