The part of the food tube where the GI tract and respiratory tract cross each other is the pharynx.

Here's why:

* Pharynx: This is the muscular tube at the back of the throat that connects the nasal cavity and mouth to the esophagus (digestive system) and the larynx (respiratory system).

* Food & Air: When we swallow, the epiglottis (a flap of cartilage) closes off the opening to the larynx, preventing food from entering the trachea (windpipe). This allows food to pass safely into the esophagus. When we breathe, the epiglottis is open, allowing air to pass through the larynx and into the trachea.

Therefore, the pharynx is the crucial point where the pathways for food and air intersect.