besides connecting the pharynx to the ear what other purpose does the eustachian tube serve
Middle ear The middle ear is hollow. In a high-altitude environment or on diving into water, there will be a pressure difference between the middle ear and the outside environment. This pressure will pose a risk of bursting or otherwise damaging the tympanum if it is not relieved. If middle ear pressure remains low, the ear drum may become retracted into the middle ear <cite>. One of the functions of the Eustachian tubes that connect the middle ear to the nasopharynx is to help keep middle ear pressure the same as air pressure. The Eustachian tubes are normally pinched off at the nose end, to prevent being clogged with mucus, but they may be opened by lowering and protruding the jaw; this is why yawning or chewing helps relieve the pressure felt in the ears when on board an aircraft.
Cerebellar tentorium It covers the top of the cerebellum, and supports the occipital lobes of the brain.
Vein Veins are less muscular than arteries and are often closer to the skin. There are valves in most veins to prevent backflow.
Fallopian tube They are named after their discoverer, the 16th century Italian anatomist Gabriele Falloppio, who thought they resembled tubas, the plural of tuba in Italian being tube.[7]