the upper part called the nasopharynx, the middle part called the oropharynx, and the lower part called the hypopharynx. The Eustachian tube opens into the nasopharynx.
The Eustachian tube measures only 17-18mm and is horizontal at birth. As it grows to double that length, it grows to be at an incline of 45 degrees in adulthood so that the nasopharyngeal orifice (opening) in the adult is significantly below the tympanic orifice (the opening in the middle ear near the ear drum).
The shorter length and the horizontality of the Eustachian tube in infancy protects the middle ear poorly, makes for poor drainage of fluid from the middle ear, and predisposes infants and young children to middle ear infection. The greater length and particularly the slope of the tube as it grows serves more effectively to protect, aerate and drain the middle ear.
The Eustachian tube in the adult is opened by two muscles (the tensor palati and the levator palati) but the anatomy of children permits only one of these muscles (the tensor palati) to work. This is a particular problem for children born with cleft palate who have poor function of that muscle; they suffer from Eustachian tube and middle ear problems until the second muscle (the levator palati) begins to function.
The tube serves to adjust the pressure of the air within the middle ear to that of ambient air. It is harder to get air into the middle ear than get it out, which is why we have more trouble with our ears when a plane is descending than when it takes off.
The tube bears the name of Bartolommeo Eustachi, a 16th-century (c. 1500-1510 to 1574) Italian physician. In 1562 and 1563 he produced a remarkable series of treatises on the kidney, the teeth, and the ear. These were published in Opuscula anatomica (1564). The treatise on the kidney was the first work specifically dedicated to that organ. He was the first to study the teeth in any detail. The treatise on the ear, the auditory organ (De auditus organis), provided a correct account of the auditory tube that is still referred to by his name. In 1552 Eustachi prepared a series of 47 anatomical plates, which (although they were published long after his death) alone assured him a distinguished position in the history of anatomy. He placed anatomy in the service of medicine. With Vesalius and Falloppio (of Fallopian tube fame), Eustachi is often seen as one of the three heroes of human anatomy. (Historical information based on the Catalog of the Scientific Community of the 16th and 17th Centuries by Richard S Westfall for the Galileo Project.)
- Tube, ear
A small tube inserted into the eardrum to keep the middle ear aerated for a prolonged period of time. These ventilating tubes usually remain in place for 6 months to several years. Eventually, they move out of the eardrum (extrude) and fall out into the ear canal. Also called tympanostomy tubes.
- Tube, endotracheal
A flexible plastic tube that is put in the mouth and then inserted through the vocal cords down into the trachea (the airway). The doctor inserts the tube with the help of a laryngoscope. The procedure is called endotracheal intubation. The purpose is to ventilate the lungs.
- Tube, Eustachian
the upper part called the nasopharynx, the middle part called the oropharynx, and the lower part called the hypopharynx. The Eustachian tube opens into the nasopharynx. The Eustachian tube measures only 17-18mm and is horizontal at birth. As it grows to double that length, it grows to be at an incline of 45 degrees in […]
- Tube, Fallopian
a pregnancy developing in the Fallopian tube or another abnormal location outside the uterus. These tubes bear the name of Gabriele Falloppio (also spelled Falloppia), a 16th-century (c. 1523-62) Italian physician and surgeon who was expert in anatomy, physiology and pharmacology. He was an early expert on syphilis and one of the great surgeons of […]
- Tube, NG
An NG (nasogastric) tube is one that is passed through the nose (via the nasopharynx and esophagus) down into the stomach. An NG tube is a flexible tube made of rubber or plastic and has bidirectional potential. A nasogastric tube can thus be used to remove the contents of the stomach including air (to decompress […]