Where are the larynx, pharynx, and trachea located? Which of these is the tube that forms two branches--one going to the lungs and the other to the esophagus?

That is the laryngeal pharynx or laryngopharynx, the space above the larynx and the esophagus.

Larynx: posterior to the thyroid gland, anterior to the C4 and oesophagus, medial to the hyoid bone.

Pharynx: divides into three parts: naso, oro, and laryngopharynx. (See the picture below).

Trachea: inferior to the larynx, medial to the lungs, superior to the diaphragm, superoanterior to the heart, anterior to the thymus, posterior to the sternum.

The pharynx becomes the . The lower end of the pharynx (laryngeal pharynx) is connected to the larynx, but the covers the opening to the larynx when eating so that food continues to the esophagus.

Your trachea and your esophagus, the tube that goes into your stomach, are not supposed to be connected. If the two are connected, this is called a tracheoesophageal fistula and it is dangerous. Material meant for your stomach can enter the lungs.