passageway, passage - a path or channel or duct through or along which something may pass; "the nasal passages"

muscle system, muscular structure, musculature - the muscular system of an organism

alimentary canal, alimentary tract, digestive tract, digestive tube, gastrointestinal tract, GI tract - tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination

epicardia - the short part of the esophagus extending downward from the diaphragm to the stomach

cardiac sphincter - the valve between the distal end of the esophagus and the stomach; the physiological sphincter at the esophagogastric junction