Pharynx

The pharynx is an organ in the back of the throat. It is also the meeting point of the digestive and the respiratory systems. The opening of the respiratory system in the pharynx is called the glottis. It is guarded by a cartilagenous flap called the epiglottis which prevents food or liquid from going into the respiratory system. It closes during swallowing action. As such, it is part of the gastrointestinal system. It comes after the mouth and before the esophagus. Food and air go through the pharynx. The pharynx keeps food and liquids out of the lungs.

The 3 parts of the pharynx can be thought of as where 3 tubes (nose, mouth, windpipe) connect to it

The pharynx has 3 parts:

Nasopharynx - the upper part of the back of the throat, that leads up into the nose
Oropharynx - the part at the back of the throat
Laryngopharynx - the bottom part, before the windpipe and esophagus split from 1 into 2 tubes