Within the femoral triangle, the femoral artery lies between which two structures in the femoral sheath?

Explanation

## Contents of the Femoral Sheath and Their Arrangement ### The Femoral Sheath The femoral sheath is a funnel-shaped fascial covering derived from the fascia transversalis and iliopectineal fascia. It encloses the femoral vessels and lymphatics for approximately 4 cm below the inguinal ligament. **Key Point:** The femoral sheath is divided into three compartments by septa: 1. **Lateral compartment** — contains the femoral nerve 2. **Middle compartment** — contains the femoral artery 3. **Medial compartment** — contains the femoral vein and lymph vessels ### Spatial Arrangement (Lateral to Medial) ``` Lateral ← → Medial [Nerve] [Artery] [Vein] N A V ``` **Mnemonic:** **NAV** (Nerve-Artery-Vein) — remember this is the order from **lateral to medial** within the sheath, NOT the common "VAN" mnemonic which refers to the order of structures you encounter during dissection from superficial to deep. **High-Yield:** The femoral artery is therefore: - Medial to the femoral nerve - Lateral to the femoral vein ### Clinical Correlations **Clinical Pearl:** - Femoral artery puncture is performed just below the inguinal ligament at the midpoint of the triangle - Femoral nerve injury can occur with high femoral puncture (above the inguinal ligament) - Femoral vein thrombosis is a risk of prolonged femoral catheterization - Femoral hernia protrudes through the medial compartment (medial to the femoral vein) **Warning:** Do not confuse the arrangement within the sheath (NAV) with the superficial-to-deep order encountered during dissection. The femoral nerve lies outside the sheath and is lateral to it.