The ear drum is located in the deepest part of the external auditory canal.
The external auditory canal is divided into two parts, the bony part and the cartilaginous part, usually the inner 2/3 is the bony part and the outer 1/3 is the cartilaginous part. The posterior and superior parts of the bony part of the external auditory canal consist of the squamous part of the temporal bone, and the anterior, inferior and partly posterior walls of the bony part of the external auditory canal consist of the bony part of the temporal bone, the inner end of which forms the tympanic sulcus.
The tympanic membrane is divided into two parts, the tension part and the relaxation part, the tympanic membrane circumference is slightly thicker, most of the borrowed fibrocartilage ring embedded in the tympanic sulcus, the name of the tension part, in the tension part of the tympanic sulcus above the absence of the drum cut at the drum track, the tympanic membrane attached to the temporal bone scales part, more relaxed than the tension part, known as the relaxation part.
The tympanic membrane is the dividing line between the external auditory canal and the middle ear. Inflammation of the external ear often causes inflammation of the tympanic membrane and then leads to inflammation of the middle ear.