1 — Oesophagus; 2 — Cricoid cartilage; 3 — Killian triangle; 4 — Thyroid cartilage; 5 — Pharyngeal raphe; 6 — Inferior constrictor, thyropharyngeal part, thyropharyngeus; 7 — Inferior constrictor, cricopharyngeal part; cricopharyngeus; 8 — Muscular layer; Muscular coat, circular layer; 9 — Tracheal cartilages; 10 — Trachea; 11 — Muscular layer; Muscular coat, longitudinal layer; 12 — Submucosa; 13 — Mucosa; Mucous membrane
