The Eustachian tube is a part of the middle ear and is the only passage between the middle ear’s tympanic chamber and the outside world, one on each side. The Eustachian tube has two orifices, the tympanic orifice of the Eustachian tube opens on the upper part of the anterior wall of the tympanic chamber, and the pharyngeal orifice of the Eustachian tube is located on the lateral wall of the nasopharynx, just behind and above the posterior end of the inferior turbinate. If the Eustachian tube pharyngeal orifice is positioned from the nose, the Eustachian tube pharyngeal orifice is at the posterior end of the inferior turbinate, on either side of the nasopharynx. If you locate the pharyngopharyngeal opening from the mouth, you can see the uvula and soft palate when you open your mouth, and there is an opening for the pharyngopharyngeal tube on both sides of the nasopharynx, just behind and above the uvula and soft palate. The other opening of the Eustachian tube is in the tympanic cavity, which is not visible in the anterior wall of the tympanic cavity. The tympanic orifice of the Eustachian tube reaches inward, downward, and forward to the pharyngeal orifice, which is at an angle of approximately 40 degrees to the horizontal plane and 45 degrees to the sagittal plane. The mouth of the eustachian tube opens to regulate the pressure within the tympanic chamber and maintains a balance between the pressure inside and outside the tympanic membrane.