USMLE Anatomy

Question 1

The femoral sheath is divided into three compartments. Which structure occupies the most medial compartment (femoral canal)?

Accepted Answer

Lymphatics and loose connective tissue

Answer

The femoral canal is the most medial compartment of the femoral sheath and contains lymphatics and loose connective tissue, forming the site of potential femoral hernias.

Question 2

A patient presents with weakness of hip flexion and knee extension along with loss of sensation over the anterior thigh and medial leg. Which nerve is most likely damaged?

Accepted Answer

Femoral nerve

Answer

The femoral nerve innervates the iliopsoas (hip flexion) and quadriceps (knee extension), and its saphenous branch provides sensation to the anterior thigh and medial leg.

Question 3

During a thyroidectomy a surgeon must preserve all intrinsic laryngeal muscles. Which muscle is NOT innervated by the recurrent laryngeal nerve?

Accepted Answer

Cricothyroid

Answer

The cricothyroid is the only intrinsic laryngeal muscle innervated by the external branch of the superior laryngeal nerve, not the recurrent laryngeal nerve.

Question 4

A patient sustains a stab wound to the posterior triangle of the neck and subsequently develops shoulder droop with difficulty elevating the arm above 90 degrees. Which nerve was most likely injured?

Accepted Answer

Accessory nerve (CN XI)

Answer

The accessory nerve (CN XI) traverses the posterior triangle of the neck and innervates the trapezius; its injury causes shoulder droop and impairs full arm elevation.

Question 5

As the ureter descends into the pelvis, it crosses posterior to which structure at the pelvic brim?

Accepted Answer

Common iliac artery bifurcation

Answer

The ureter crosses posterior to the bifurcation of the common iliac artery at the pelvic brim, an important landmark during pelvic and urologic surgery.

USMLE Practice Test

USMLE Practice Test

USMLE Anatomy