Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which structure is closely related to the anatomic level of the iliac crest?

1. Calcaneus

2. Lumbar spine

3. Kidneys

4. Aorta

The correct answer is: Lumbar spine

The iliac crest, which is the superior border of the ilium, is anatomically significant as it serves as a landmark for various clinical assessments and procedures. Its location is generally at the level of the L4 vertebra in adults, making the lumbar spine closely related to it. Anatomically, this means that assessments or interventions involving the iliac crest, such as spinal anesthesia or certain surgical approaches, often take into consideration the adjacent structures of the lumbar spine. The other structures listed, such as the calcaneus, kidneys, and aorta, are not closely related to the iliac crest in the same way. The calcaneus, located in the foot, is distantly situated from the iliac crest. The kidneys are positioned more superiorly and posteriorly in the abdominal cavity and are not directly level with the iliac crest. The aorta, although it runs along the midline of the body, is also not anatomically aligned with the iliac crest. Thus, the lumbar spine is the most relevant structure in relation to the anatomic level of the iliac crest.