Practical anatomy: a manual of dissections / by Christopher Heath.

  • Christopher Heath
Date:
1870
Catalogue details

Licence: Public Domain Mark

Credit: Practical anatomy: a manual of dissections / by Christopher Heath. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    471/600 (page 461)
    The Tympanum or Middle Ear (Fig. 211) is an irregularly six-sided cavity, which may be conveniently said to resemble a room with a passage (meatus auditorius externus) leading to it. The outer wall of the chamber is formed by the mem- brana tympani, which is placed obliquely at the end of the meatus ; the inner wall corresponds to the outer wall of the vestibule ; in front, is the opening of the Eustachian tube with the special tube for the tensor tympani muscle formed by the processus cochleariformis; behind, is the opening into the mastoid cells. The roof of the chamber is a thin portion of bone separating it from the cavity of the cranium ; the ^oor is a thicker portion corresponding to the jugular fossa. Fig. 211. IxTEEXAL VIEW OF Otic GANGLION AKD TrMPANtJM (fi'om Hii'sclifeld and LeveilI6). 1. Sensory portion of oth nerve with Gasserian ganglion. 2. Tensor tympani muscle (cut). 3. Motor portion of 5th passing beneath the ganglion. 4. Malleus. 5. Small superficial petrosal nerve of Arnold. 6. Incus. 7. Otic ganglion. 8. Facial nerve. 9. Chorda tympani [nerve]. 10. Membrana tympani. 11. Tensor palati muscle (cut). 12. Middle meningeal artery. 13. 13. Lingual nerve (5th). l-t. Auriculotemporal nerve. 15. Inferior dental nerve (5th). 16. Pterygoideus externus. 17. Pterygoideus internus. IS. Internal maxillary artery. 20, 20. Mylo-hyoid uerve. The inner wall is the most important, and presents the following points for examination (Pig. 206, p. 450); (1) 3y*