The femoral artery enters the femoral triangle by passing deep to which ligament?

Explanation

## Entry of Femoral Artery into the Femoral Triangle The femoral artery is the continuation of the external iliac artery and enters the femoral triangle at a specific anatomical point: ### Anatomical Course 1. **External iliac artery** becomes the femoral artery as it crosses the **inguinal ligament** 2. The artery passes **deep (posterior)** to the inguinal ligament 3. It enters the femoral sheath, which is a tubular extension of the fascia transversalis and iliopectineal fascia 4. The femoral triangle begins immediately below the inguinal ligament **Key Point:** The femoral artery passes deep to the inguinal ligament at the **midinguinal point** (midway between the anterior superior iliac spine and the pubic symphysis). This is the landmark for femoral artery puncture in clinical practice. **Clinical Pearl:** The inguinal ligament is a key landmark — it stretches between the anterior superior iliac spine (ASIS) and the pubic tubercle. Structures passing deep to it include the femoral artery, vein, and nerve, as well as the iliopsoas muscle and femoral branch of the genitofemoral nerve. **High-Yield:** The **lacunar ligament** (medial part of the inguinal ligament) and **pectineal ligament** are separate structures that do not directly relate to the main course of the femoral artery — they bound the femoral sheath medially. **Mnemonic:** **VAIN** — **V**ein, **A**rtery, **I**liopectineal fascia, **N**erve — these pass deep to the inguinal ligament in the femoral sheath.