Esophagus

Anatomy

Histology

Nerves

UES: cricopharyngeus + lower fibers of inferior pharyngeal constrictor. Normally constricted, tonically relaxed for food

Esophageal fibers: upper 1/3 striated, lower 1/3 smooth

LES: high pressure zone

Histology: Mucosa, submucosa (Meissner's plexus), muscularis externa (Aufbauf's plexus), adventitia

Nerves: Originate in DMN, innervates the meissner's plexus. Excitatory: Ach. Inhibitory: NO, VIP

1) Oral preperation: production of bolus

2) Oral voluntary phase: act of swallowing food

3) Pharygeal phase: the pharynx closes, the larynx elevates and closes the respiratory tract, the pharynx pushes food towards the UES

4) Esophageal phase: the UES opens, and the esphagus swallows to push food down

Causes: LES low pressure or transient opening, esphageal impaired mucosal clearing, excessive gastric acid secretion or distention, or diet, smoking, and medications

Symptoms: heart burn, dysphagia, chest pain, regurgitation, dysphagia, water brash. Atypical include hoarseness, cough, larygitis, laryngeal cancer, dental erosions, sinusitis

Testing: history, physical, barium swallow, endoscopy, manometry

Complications: esophagitis, esophageal strictures, Barrets, adenocarcinoma

Treatment: lifestyle changes, H2 blockers, PPIs, nissen fundoscopy