trachea and esophagus cross section

human trachea esophagus animal esophagus food gaseous exchange vertebrate peristalsis muscular contraction stomach pharynx heart internal organ eating epiglottis lung larynx respiratory tract voice mucosa bronchus submucosa tissue anatomy muscle epithelium biological cell cilium goblet cell coughing infectious disease bacterium gastroesophageal reflux disease acid blood nerve cell medicine anatomy biology diagram inhaling exhaling cartilage lymph node human gland artery vein lumen isolated color blood vessel