Tympanic Canaliculus

Tympanic tubule, canaliculus tympanicus, pna/bna/jna

**The tympanic (Eustachian) canal** is a small formation on the border between the middle ear and the pharynx, which is a narrow canal connecting the tympanic cavity of the middle ear with the external environment. A number of studies of the functions of the tympanic cavity have shown that the baroreceptors of the tympanic (Eustachian) canal can respond to changes in pressure and transmit a signal to the auditory analyzer. When the tympanic canal is filled with air or serous fluid during inspiration, the palatine plates of the soft palate close and the air entrance to the tympanic cavity closes. During exhalation, the pressure in the tympanic cavity increases, the pyogycyl membrane of the tympanic membrane rises, and air and sinus (from the eustachian tube) are removed through the tympanic canal into the nasopharynx. But normally (usually in a sitting position, not lying down and not on high steps: if you find it difficult to breathe when climbing stairs to high steps, check the course of the tympanic tubule), the same mechanism protects the auditory ossicles from the action of the Coriolis force (the force arising during body rotation) and shifts the point of maximum sound pressure to the region of the rear edge of the round window. The Eustachian tube helps balance the pressure difference between the internal and external auditory canals. The length of the tympanum in a child is 37–40 mm, in an adult it is about 35 mm. The width of the tympanic entrance due to three trabeculae is about 1.5 mm, then it expands to 8–10 mm (in length); the inlet cross-section has an elliptical shape. The section of the tympanic tube at the level of the tympanic joint is oval, behind the tympanic joint, the length of which is 6.6–7.6 mm, it is slightly widening cone-shaped with a diameter of the outlet at the height of the umbilicus of 19–23 mm. The base of the pyramid is two-walled-three-layered, in the anterior section 4 tissue plates covering the periosteal tissue lie next to each other, on average - the middle ear overlaps the edge of the periosteal layer, and the posteroposterior edge borders on it, in the posterior section the bone shell does not reach the edge of the periosteal plate . The length of the wall of the tympanic tube is 4–5 mm; the length of the pedicle bordering the bone spindle is about 9 mm. The cartilage indentation pedicle is about 6 mm long and 12–15 mm in diameter. The hairy auditory canaliculus begins in the semicircular recess and, after the superior bony groove, enters between the upper edge of the posterior edge of the perichondrium and the fibers of the perilymphatic space, passes into the posterior tympanic groove on the concha, rises up and turns medially along the anterior neck of the malleus. Its thickness is about 0.15–0.20 mm; inside it there is a vein of steel blue color; their general department (sometimes the entire