Pharynx, Nasopharynx

From the oral cavity, food enters the pharynx - the cavity located behind the soft palate and tongue, where the paths of the respiratory and digestive systems intersect. Seven different passages communicate with the pharynx: the oral cavity, two choanae leading to the nasal cavity, the larynx connecting the pharynx to the trachea, the esophagus leading to the stomach, and two Eustachian tubes that go into the middle ear cavity and serve to equalize the pressure along the both sides of the eardrum.

Swallowing. Once food is prepared for swallowing, it moves from the mouth to the stomach through a complex series of reflexes. The first part of the act of swallowing is under the control of the will: the tongue rises to the palate and, with a wave-like movement, pushes the food bolus located between its back and the palate into the pharynx.

The entrance to the larynx closes as a result of contraction of the muscles that lift the entire larynx and press the edges of its entrance hole to the cartilage located above it - the epiglottis. In this case, the opening of the larynx is completely closed, which prevents food from entering the trachea, and at the same time, the entrance to the esophagus expands, facilitating the passage of the food bolus.

The nasopharynx is the upper part of the pharynx, communicating with the nasal cavity through two oval openings - the choanae. On the side walls of the nasopharynx there are openings for the auditory tubes, connecting it to the middle ear. The mucous membrane of the nasopharynx contains many mucous glands, thanks to which the air is moistened, warmed and purified. The nasopharynx is the resonator of the voice.