**Question:** Bigelow's ligament is at

A. inguinal canal
B. femoral canal
C. obturator canal
D. obturator fossa

**Core Concept:** Bigelow's ligament is a fibrous band that connects the iliacus and psoas major muscles, and plays a role in the development of inguinal hernias. It is associated with the structures it connects and the area where it is located.

**Why the Correct Answer is Right:** Bigelow's ligament is at the **inguinal canal** (Option A). The inguinal canal is a part of the deeper inguinal ring, which is formed by the inferior epigastric artery, vein, and nerve, as well as the internal iliac artery, vein, and plexus. The ligament connects the iliacus and psoas major muscles, and its insertion into the wall of the inguinal canal causes tension on the canal wall, potentially leading to hernia formation.

**Why Each Wrong Option is Incorrect:**

- **Option B (femoral canal)** is incorrect because it refers to the femoral canal, which is a different structure containing the femoral nerve, artery, and vein and is unrelated to the inguinal region and Bigelow's ligament.
- **Option C (obturator canal)** is incorrect because it refers to the obturator canal, which is a part of the obturator fossa. The obturator fossa is a region near the obturator foramen, and the obturator canal is not related to Bigelow's ligament or the inguinal region.
- **Option D (obturator fossa)** is incorrect as it refers to the obturator fossa, which is a region near the obturator foramen. The obturator fossa contains the obturator nerve, artery, and vein but is not directly related to the inguinal region or Bigelow's ligament.

**Clinical Pearl:** Understanding the relationship between Bigelow's ligament, the inguinal canal, and the development of inguinal hernias is crucial for diagnosing and treating patients with these conditions. A thorough physical examination and history-taking are essential to assess for signs of a hernia, such as a pulsatile mass or a palpable inguinal crease.