. Text-book of normal histology: including an account of the development of the tissues and of the organs. uent. From ^34 NORMAL HISTOLOGY. this peripheral lamella trabeculse extend across the interveningperilymphatic space to the hbrou^ wall of the membranous laby-rinth. The endothelium of the inner surface of the periosteuminvests the fibrous trabcculae as well as the outer or perilymphaticsurface of the membranous labyrinth. The walls of the saccule and the utricle consist of the con-nective-tissue lamella, composed of the bundles of fibrous tissueand the delicate epithelium. At the positio
. Text-book of normal histology: including an account of the development of the tissues and of the organs. uent. From ^34 NORMAL HISTOLOGY. this peripheral lamella trabeculse extend across the interveningperilymphatic space to the hbrou^ wall of the membranous laby-rinth. The endothelium of the inner surface of the periosteuminvests the fibrous trabcculae as well as the outer or perilymphaticsurface of the membranous labyrinth. The walls of the saccule and the utricle consist of the con-nective-tissue lamella, composed of the bundles of fibrous tissueand the delicate epithelium. At the positions where the filamentsof the auditory nerve enter the maculae cribrosae and acusticaethe fibrous stratum is best developed and densest, forming a to .20 mm. thick. Within other parts of the vestibule, especiallyin the roof of the utricle, the thickness of this layer may be reducedto 5-6 ,«. The lining of the saccule and the utricle consists everywhere,except at the macula; acusticae, of a single layer of thin flattenedpolyhedral cells. Over the regions receiving the terminations of Fig. Section through membranous labyrinth of cat, showing specialized areas withinampulla (^4) and utricle {B): a, surrounding bony wall separated from membranoustube (b) by layer of areolar trabeculae (d) \ c, crista acustica covered with specializedepithelium {/); e, f, bundles of nerve-fibres ; ^, ordinary epithelium; /;, layer ofotoliths overlying neuro-epithelium of macula acustica (_/); i, blood-vessel; k, fibrouslayer ; /, adipose tissue. the nerve-fibres, the maculae acusticae, on the contrary, the epi-thelium undergoes marked alteration, changing from the indifferentcovering cells into the highly-specialized neuro-epithelium. Atthe margin of these areas the cells are at first cuboidal, then low THE ORGAN OF HEARING. 385 columnar, and progressively increase in length until they measure30-35 //. in contrast with their usual height of 3-4 ,a. The character and arrangement of the
Size: 1679px × 1488px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherphiladelphiajblipp
