Esophagus

Function

The oesophagus is a 25 cm muscular tube whose only job is transport — yet it performs it with precision: a swallow's peristaltic wave reaches the stomach in 8–10 seconds, travelling through three anatomic narrowings (the cricopharyngeus at 15 cm, the aortic arch/bronchus crossing at 22 cm, and the diaphragmatic hiatus at 40 cm from the incisors) that record the distances endoscopists quote.

Its upper third is striated muscle (voluntary swallow), the middle a blend, the lower third smooth — the automatic peristalsis that keeps working even upside-down. The lower oesophageal sphincter holds a 2–3 cm high-pressure zone against reflux, aided externally by the diaphragm's pinch.

Blood supply

Inferior thyroid, oesophageal branches of the aorta, left gastric artery.

Nerve supply

Vagus (parasympathetic motor and secretomotor), sympathetic from the thoracic chain.

Clinical relevance

GORD (reflux)

A leaky sphincter lets gastric acid scald the squamous lining — heartburn, and in some, Barrett's metaplasia toward adenocarcinoma.

Achalasia

Failed LES relaxation plus absent peristalsis stores food in a dilated oesophagus — dysphagia to solids and liquids alike.

Oesophageal varices

Portal hypertension shunts blood into the submucosal veins of the lower third; rupture bleeds catastrophically.

Related conditions

• Gastro-oesophageal reflux disease
• Oesophageal cancer
• Achalasia