Anatomical study between the correlation of the arcuate eminence and the superior semicircular canal.

OBJECTIVE: To study the anatomical correlation between the arcuate eminence and the superior semicircular canal. MATERIAL AND METHODS: A study of the height of the arcuate eminence was carried out in 295 temporal bones. In addition, 30 temporals with different heights of the arcuate eminence (10 flat, 10 prominent and 10 very prominent) were randomly selected and radiological tests were performed by computed tomography (Pöschl projection) and subsequent dissection by milling until the apex of the superior semicircular canal was found, establishing, with both methods, the anatomical relationship with the arcuate eminence. RESULTS: The arcuate eminence was classified as: smooth, when there was no relief (1.7%); flat, measured less than 1 mm (20.3%), prominent, measured between 1 and 2 mm, in (62%), and very prominent, measured above 2 mm (12.6%). The tomographic study (CT) and its subsequent dissection by bone milling showed a direct relationship between the arcuate eminence and the semicircular canal only when it was flat, while the rest of the types corresponded to the presence of pneumatized peri-labyrinthine cells and/or cancellous bone without a direct anatomical relationship with the apex of the superior semicircular canal. CONCLUSION: The correlation between the arcuate eminence and the superior semicircular canal is direct only when it is flat (1 mm), being related to peri-labyrinthine cells and/or cancellous bone when the arcuate eminence is prominent or very prominent.

Association between superior semicircular canal dehiscence and other dehiscences in temporal bone.

BACKGROUND: The study of the association between superior semicircular canal and other dehiscences in the temporal bone. MATERIALS AND METHODS: We have studied computed tomography of radiologically diagnosed people with superior or posterior semicircular canal dehiscences, in four health centres. In addition, we have studied one isolated human temporal bone, one skull and one cadaver head belonging to the collection of the Department of Human Anatomy and Histology of the University of Zaragoza that had dehiscence in the superior semicircular canal. RESULTS: The most frequent association that we observed was between superior semicircular canal dehiscence and tegmen tympani dehiscence (37.33%). Three cases (two clinical cases and one isolated temporal bone) showed multiple associated dehiscences (tegmen tympani, mastoid antrum, posterior semicircular canal, internal auditory canal, glenoid cavity, tympanum bone and geniculate ganglion) associated with superior semicircular canal dehiscence. CONCLUSIONS: When the superior semicircular canal dehiscence is associated to other in the petrous bone (tegmen tympani, mastoid antrum, posterior semicircular canal, internal auditory canal) could be grouped into the same syndrome called "otic capsule syndrome", since they have the same origin and common aetiology (otic capsule).

Morphometric study of testis of Wistar rat after open-ended vasectomy.

The effects on the testis of open-ended vasectomy in the Wistar rat have been assessed morphometrically and evaluated statistically at 1, 4, 12, and 24 weeks after operation, and compared to those in sham-operated controls. The open-ended technique, ie, without ligation of the epididymal end of the cut ductus deferens, allowed drainage of sperm into the spermatic cord. During the period of our study, it did not affect the structure of the testis; although the germinal epithelium, basement membrane, and the stroma and cells of the interstitial space all showed variations when compared to the control group, these were not statistically significant.

Fetal development of the human tympanic ossicular chain articulations.

OBJECTIVES: To obtain further knowledge on the morphogenesis of the articulations in the tympanic ossicular chain in humans. MATERIAL AND METHODS: In 25 temporal bones of human fetuses the structural development of incudomallear, incudostapedial and stapediovestibular articulations was studied. The chronological ages were between the 7th week (21 mm) and the 29th week (270 mm). RESULTS AND DISCUSSION: Incudomallear articulation showed diarthrosis and sellar joint characteristics. It showed a homogenous interzone in the 7th week of development, a three-layered interzone in the 8th week, the first cavitation signs in the 9th week and the presence of an articular cavity in the 10th week. The presence of a hyaline cartilage covering articular surfaces was observed starting in the 20th week of development. Incudostapedial articulation showed typical characteristics of a diarthrosis and spheroidal joint with a homogenous interzone at the 7th week, showing similar characteristics for 12 weeks, and completed its cavitation at the 16th week. We observed hyaline cartilage on articular surfaces from 29 weeks. Stapediovestibular articulation showed typical characteristics of syndesmosis. The annular ligament primordium derived from cartilage differentiation, both from stapedial footplate and from the surrounding otic capsule, into mesenchyme and its subsequent transformation into fibrous tissue, reaching definitive characteristics from the 12th week.

[Structural peculiarities of the human cerebral communicating arteries and their repercussion in encephalic vascular pathology]. / Peculiaridades estructurales de las arterias comunicantes cerebrales humanas y su repercusión en la patología vascular encefálica.

INTRODUCTION: The cerebrovascular accidents are one of the most frequent causes of morbimortality. Most of them are caused for the break of aneurysms in communicating arteries. The weak structure of these vessels explain the reason of these accidents. OBJECTIVE: The reason of this paper is study the organization of communicating arteries as cause of this fragility. Material and methods. The material of this study is composed of 61 human cerebral communicating arteries, grouped in decades. The study has been carried out by histological routine. RESULTS: In general the structure of cerebral communicating arteries is characterized for the thinness and irregularity of the wall. In the childhood the internal elastic membrane and tunica media show thicker, while in young and adult people appear elastic fibers and reticulin as well as smooth muscle cells in tunica media. In adulthood (50 60 years) collagen in adventicia occupies tunica media, and adventicia is weaked. There are frequent media defects in these communicating arteries, that are usually repaired for conjunctive tissue stopper with abundance of collagen fibers. Starting from 4th decade the internal elastic membrane shows a great number of fenestrae through muscle and fiber tissue of media occupying subintimal space. Doubtless media defects mean the most severe threat of vascular outbreak. CONCLUSION: The structural evolution with the age of communicating arteries, with predominance of collagen over elastin and reticulin, could be their reason of fragility.

Contributions to the study of the foetal development of physiological intimal thickening in the human uterine artery.

The morphological study of the development of "intimal thickenings" of the human uterine artery in physiological condition was performed on 72 uterine arteries obtained from foetuses from the 12th week of gestation up to birth. Our results indicate that intimal thickening is formed by the migration and displacement of mesenchymal cells around the site of origin of collateral vessel from uterine mesothelium. These cells firstly differentiate into the myoblasts and then into the myocites. During the development the internal limitans membrane separates the intimal thickening from the tunica media and the elastic fibres appearing inside possessing a muscle-elastic nature. The function of intimal thickenings is the regulation of local blood flow by means of the control of myocitic contractile capacity; these cells play a fundamental role in endothelium-intimal smooth muscle cell contact.

Peculiaridades estructurales de las arterias comunicantes cerebrales humanas y su repercusión en la patología vascular encefálica / Structural peculiarities of the human cerebral communicating arteries and their repercussion in encephalic vascular pathology

Introduccción. Los accidentes cerebrovasculares son una de las causas más frecuentes de morbimortalidad. Buena parte de ellos son producidos por la ruptura de aneurismas de las arterias comunicantes. La débil estructura de estos vasos explica la razón de esos accidentes. Objetivo. El motivo del trabajo estriba en estudiar la organización de la arterias comunicantes como causa de esa fragilidad. Material y métodos. El material del presente estudio lo componen 61 arterias comunicantes cerebrales humanas, agrupadas por décadas. Las piezas siguen la rutina histológica. Resultados. La tónica general en la estructura de las arterias comunicantes cerebrales es la delgadez e irregularidad de su pared. En la infancia la membrana elástica interna (MEI) y la túnica media presentan mayor grosor. En el joven y adulto aparecen en la túnica media fibras elásticas y de reticulina amén de las musculares lisas. En la madurez (50-60 años) el colágeno adventicial ocupa la túnica media y la adventicia se debilita. Son frecuentes en estas comunicantes los denominados `defectos mediales', que suelen ser reparados mediante `tapones' de tejido conjuntivo, con abundancia de fibras colágenas. A partir de la cuarta década, la MEI presenta un buen número de fenestraciones, a través de las cuales el tejido fibroso y muscular liso de la media penetra hasta el espacio subintimal. Sin duda, los defectos mediales representan la amenaza más grave de estallido vascular. Conclusión. Con la edad, la evolución estructural de las arterias comunicantes, con predominio del colágeno sobre la elástica y reticulina, puede ser el motivo de su fragilidad (AU)

The vasectomized testis.

We have performed a qualitative study on effects of vasectomy on the testicular structure. Vasectomy performed with the traditional technique changes testicular structure. At first, the injuries are slight and restricted, but gradually, and in a time-dependent manner, become more severe and extensive. Ultrastructure studies indicate that the spermatogonia and Sertoli's cells are the most resistant to vasectomy, and are even observed in some regenerating testes lacking a complete germinal epithelium. Morphometric studies revealed a decrease in epithelial depth, an increase in the thickness of the basement membrane and in surface of the interstitial space, all significant (P < 0.01) with respect to the control. However, the percentage of the interstitial tissue occupied by cells, did not show any significant difference. We propose that the increase of intraluminal pressure is the essential factor that provokes testicular atrophy.