Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the anatomical landmark corresponding to the tip of the 9th costal cartilage?

1. Fundus of the gallbladder

2. Superior mesenteric artery

3. Body of the pancreas

4. Right kidney

The correct answer is: Fundus of the gallbladder

The anatomical landmark at the tip of the 9th costal cartilage is indeed associated with the fundus of the gallbladder. This region serves as a reference point in clinical anatomy as it is located at the level of the transpyloric plane, which is often used in abdominal examinations and procedures. The tip of the 9th costal cartilage corresponds roughly to the lateral border of the rectus abdominis muscle and runs anteriorly to the mid-axillary line. The gallbladder sits inferior to the liver, and the fundus is the part that projects forward, easily located at this anatomical landmark. Understanding this correlation is vital for surgeries and diagnostics, especially when assessing gallbladder pathology, such as cholecystitis or gallstones. In context, the superior mesenteric artery is located slightly higher, closer to the first lumbar vertebra, while the body of the pancreas is located more posteriorly and does not align with the 9th costal cartilage. The right kidney, situated lower and more posterior than the gallbladder, also doesn't correlate with this specific landmark. Hence, the association of the tip of the 9th costal cartilage with the fundus of the gallbladder is anatomically