From Wikipedia, the free encyclopedia
- Umbo is also a term for a shield boss and for the swollen (oldest) part of a bivalve (clam, mussel, etc) shell near the ligament that holds together the two shell valves.
| Umbo of tympanic membrane |
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| The tympanic membrane viewed from within. The malleus has been resected immediately beyond its lateral process, in order to show the tympanomalleolar folds and the membrana flaccida. 1. Tympanic membrane. 2. Umbo. 3. Handle of the malleus. 4. Lateral process. 5. Anterior tympanomalleolar fold. 6. Posterior tympanomalleolar fold. 7. Pars flaccida. 8. Anterior pouch of Tröltsch. 9. Posterior pouch of Tröltsch. 10. Fibrocartilaginous ring. 11. Petrotympanic fissure. 12. Auditory tube. 13. Iter chordae posterius. 14. Iter chordæ anterius. 15. Fossa incudis for short crus of the incus. 16. Prominentia styloidea. |
| Latin |
umbo membranae tympanicae |
| Gray's |
subject #230 1039 |
| Dorlands/Elsevier |
u_02/12836090 |
The umbo is the most depressed part of the tympanic membrane.
[edit] Depression
The manubrium of the malleus is firmly attached to the medial surface of the membrane as far as its center, which it draws toward the tympanic cavity; the lateral surface of the membrane is thus concave, and the most depressed part of this concavity is named the umbo.
[edit] External links
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
