anatomy of trachea and esophagus

trachea esophagus oesophagus food respiration vertebrate peristaltic contraction stomach pharynx heart swallowing epiglottis lung larynx airway voice mucosa bronchi submucosa tissue muscle epithelium cell cilia goblet cough infection bacteria reflux acid blood nerve medicine anatomy biology diagram inhale exhale cartilage lymph gland artery vein lumen isolated vessel