dots-menu
×

Home  »  Anatomy of the Human Body  »  pages 1056

Henry Gray (1825–1861). Anatomy of the Human Body. 1918.

pages 1056


Basilar Membrane.—The basilar membrane stretches from the tympanic lip of the osseous spiral lamina to the basilar crest and consists of two parts, an inner and an outer. The inner is thin, and is named the zona arcuata: it supports the spiral organ of Corti. The outer is thicker and striated, and is termed the zona pectinata. The under surface of the membrane is covered by a layer of vascular connective tissue; one of the vessels in this tissue is somewhat larger than the rest, and is named the vas spirale; it lies below Corti’s tunnel.


FIG. 930– Limbus laminæ spiralis and membrana basilaris. (Schematic.) 1, 1’. Upper and lower lamellæ of the lamina spiralis ossea. 2. Limbus laminæ spiralis, with a, the teeth of the first row; b, b’, the auditory teeth of the other rows; c, c’, the interdental grooves and the cells which are lodged in them. 3. Sulcus spiralis internus, with 3’, its labium vestibulare, and 3”, its labium tympanicum. 4. Foramina nervosa, giving passage to the nerves from the ganglion spirale or ganglion of Corti. 5. Vas spirale. 6. Zona arcuata, and 6’, zona pectinata of the basilar membrane, with a, its hyaline layer, B, its connective-tissue layer. 7. Arch of spiral organ, with 7’, its inner rod, and 7”, its outer rod. 8. Feet of the internal rods, from which the cells are removed. 9. Feet of the external rods. 10. Vestibular membrane, at its origin. (Testut.) (See enlarged image)


FIG. 931– Section through the spiral organ of Corti. Magnified. (G. Retzius.) (See enlarged image)
  The spiral organ of Corti (organon spirale [Corti]; organ of Corti) (Figs. 931, 932) is composed of a series of epithelial structures placed upon the inner part of the basilar membrane. The more central of these structures are two rows of rod-like bodies, the inner and outer rods or pillars of Corti. The bases of the rods are supported on the basilar membrane, those of the inner row at some distance from those of the