The oropharynx, or pharynx, is a passage that connects the back of the mouth and the nose to the esophagus. This muscular tube, which is lined with mucous membranes, is a part of the respiratory and the digestive systems. The top section of the pharynx is an air passage that connects the nasal cavity to the region behind the soft palate of the mouth. The middle section is a passage for both air and food and ends below the tongue. The lowest section is for food only and lies behind and to each side of the larynx, or voice box, merging with the esophagus. The average person breathes in about 13 million cubic feet of air in a lifetime. The air coming from a sneeze may reach a speed of 100 miles per hour.