INBDE (Integrated National Board Dental Examination) Practice Exam 2025 - Free Practice Questions and Study Guide

Lymphedema occurs when lymph fluid, which normally flows throughout the body's tissues and back to the heart, becomes trapped in the tissues due to an obstruction. In this case, the question is asking about the relative location of this obstruction within the body. The terms "superior" and "inferior" refer to vertical positions in the body, with superior being closer to the head and inferior being closer to the feet. These terms are not relevant to the location of the obstruction in relation to the lymph, so options C and D can be ruled out. While both "distal" and "proximal" refer to distance from a point of reference, in this context, "distal" would be the more accurate choice. "Distal" refers to a location further away from the point of obstruction, while "proximal" refers to a location closer to the point of obstruction. In the case of lymphedema, the obstruction is causing the lymph to collect in the tissues further away (distal) from the obstruction. Therefore, A is the correct answer.