The glottis is basically the opening to the pharynx. The pharynx is just the throat. Also, just so you know, the epiglottis is the flap of skin around the glottis that closes up when you're eating, so you don't choke.
The larynx is the upper part of the trachea containing the vocal cords. The pharynx is the passage that leads from the cavities of the nose and mouth to the larynx and esophagus.
the pharynx
The laryngopharynx passes food to the esophagus and air to the larynx.
Pharynx
The esophagus is distal to and inferior to the pharynx. The pharynx is proximal and superior to the esophagus.
the larynx or glottis connect the pharynx and trachea
The pharynx is the section of the throat between the skull and the esophagus that propels food when swallowed into the esophagus. The epiglottis at the bottom of the pharynx pivots to send food to the esophagus or air into the lungs by way of the voice box (larynx).
The pharynx is connected to the stomach by the esophagus. The esophagus is a muscular tube in which food passes from the pharynx to the stomach (Here's a fact: The esophagus is usually about 25-30cm long).
Actually, the opening at the back of the throat is called the oropharynx. You cannot see the glottis without special equipment. The glottis is the space between the true vocal folds (vocal cords) which leads to the trachea (windpipe).
The function of an esophagus is to conduct food between the pharynx and the stomach.
esophagus
The glottis opens to the pharynx leading to the lungs.