Regarding the anatomy of the lung hilum and its contents, all of the following statements are correct EXCEPT:

## Anatomical Relationships at the Lung Hilum ### Correct Statements **Key Point:** The left main bronchus is indeed longer (~5 cm) and more horizontal than the right main bronchus (~2.5 cm), which is more vertical and wider in caliber. **Key Point:** The pulmonary veins at the hilum are positioned **inferiorly** (below) relative to the bronchus, forming a characteristic anatomical relationship. **Key Point:** Bronchial arteries and veins are systemic vessels that supply the lung parenchyma, visceral pleura, and bronchi themselves — they are the nutritive blood supply to lung tissue. ### The Incorrect Statement **High-Yield:** At the lung hilum, the **pulmonary artery lies posteriorly and superiorly** (not anteriorly) relative to the main bronchus. The typical hilar arrangement from anterior to posterior is: 1. Bronchus (most anterior) 2. Pulmonary artery (posterior to bronchus) 3. Pulmonary veins (inferior and anterior) A useful mnemonic for hilar structures from anterior to posterior is **"BAV"** (Bronchus, Artery, Vein) — but this applies to the anteroposterior plane. The artery is **posterior**, not anterior, to the bronchus. ### Clinical Pearl **Clinical Pearl:** Misunderstanding hilar anatomy can lead to diagnostic errors on chest imaging. The pulmonary artery's posterior position relative to the bronchus is critical when interpreting CT angiography and bronchoscopy findings. ### Summary Table | Structure | Position at Hilum | | --- | --- | | Main bronchus | Most anterior; divides into lobar bronchi | | Pulmonary artery | Posterior and superior to bronchus | | Pulmonary veins | Inferior and anterior; often two on each side | | Bronchial vessels | Systemic supply; small caliber | | Lymph nodes | Scattered throughout hilum |