365 resultados para seminiferous epithelium
Resumo:
Neste trabalho é mostrada a grande quantidade de material eletrondenso intercelular no epitélio folicular de P. microps. Aparentemente, o material é captado da circulação e enviado para o folículo por meio dos espaços intercelulares, acumulando-se nos espaços intercelulares médio-apicais do epitélio e no espaço perioocítico. A acumulação é iniciada no oócito primário e prossegue até a vitelogênese. A natureza química desse material é discutida.
Resumo:
OBJETIVO: Avaliar as alterações morfológicas no epitélio traqueal de cães expostos à inalação de gases pouco condicionados, sob ventilação com tubo traqueal (TT) ou máscara laríngea (ML). MÉTODOS: Doze cães adultos foram divididos aleatoriamente em dois grupos: grupo TT (n-6) e grupo ML (n-6), submetidos à anestesia venosa e ventilação mecânica, em sistema sem reabsorção de CO2. Foram registrados parâmetros hemodinâmicos e ventilatórios, temperatura timpânica, temperatura, umidade relativa e absoluta do ar ambiente e dos gases inalados durante 3 horas. Ao término do experimento, os animais foram submetidos a eutanásia e realizadas biópsias ao longo do segmento traqueal para estudo morfológico. Três cães saudáveis foram utilizados para controle morfológico. RESULTADOS: A temperatura dos gases inalados manteve-se entre 24ºC e 26ºC, a umidade relativa entre 10% e 12%, e umidade absoluta entre 2 -3 mg H2O.L-1 sem diferença significativa entre os grupos. em ambos os grupos a análise histológica evidenciou processo inflamatório epitelial e congestão no córion, e a microscopia eletrônica de varredura mostrou agrupamento e desorganização ciliar. A microscopia eletrônica de transmissão detectou maiores alterações no grupo TT do que no ML, como alargamento das junções intercelulares, desorientação ciliar, vacuolização citoplasmática, alterações nucleares como pcinose e condensação da cromatina. CONCLUSÃO: A máscara laríngea determinou alterações menos pronunciadas no epitélio traqueal de cães expostos à inalação de gases pouco condicionados.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
The rete testis of the cat consists of 3 parts: a septal or interlobular part; a mediastinal part and a tunical part. The septal part contains the septal or transitory tubuli recti and the tubuli recti. The transitory tubules are formed as a confluence of the seminiferous tubules at the apex of the testicular lobules and the tubuli recti. The mediastinal rete is formed of long, straight channels which increase in size and become more irregular and anastomotic below the tunica albuginea at the cranial extremity of the testis. The end is characterized as the tunical part of the rete testis and communicates with the extratesticular rete testis. The channels all parts of the rete are lined by simple cuboidal or columnar epithelium. These epithelial channels are supported by a connective tissue containing smooth muscle cells. The framework tissue of the rete is more conspicuous at the cranial extremity of the testis, with a mio-connective matrix organization.
Resumo:
Few studies are available about the effect of alcohol on the epithelium of the urinary bladder. In the present investigation we studied the ultrastructure of the vesical transition epithelium of normal rats and of rats submitted to experimental chronic alcoholism. Adult rats were submitted to experimental chronic alcoholism by the ingestion of sugar cane liquor. The vesical epithelium was examined after 60, 120, 180 and 240 days of alcohol treatment by transmission electron microscopy. Surface cells presented nuclear and cytoplasmic changes and marked cellular desquamation. There was an increase in multivesicular bodies and lysosomes suggesting cell degeneration. Mast cell infiltration was observed, possibly related to increased epithelial sensitivity. Intercellular spaces were frequently observed. The transition epithelium of the urinary bladder was found to be sensitive to the action of alcohol, as demonstrated by the changes in the components of the blood-urine barrier, the greater sensitivity to inflammation, the increase in cell desquamation and the greater recycling of the apical membrane and of the fusiform vesicles of surface cells observed in alcoholic rats.
Resumo:
The purpose of this study was to examine in rats the histologic alterations of the submandibular glands and testicles induced by soy diets and zinc deficients diet. The zinc deficiency produced testicles alterations including seminiferous tubulus atrophy, germinative epithelium degeneration, spermatogenesis alterations and a significant atrophy of the submandibular glands which presented no much delimitated acines. The soy diet without complementations also compromised the spermatogenesis by showing seminiferous tubulus atrophied and a reduction of the germinative epithelium. The soy diet complemented by saline and vitaminic mixtures didn't produced testicles alterations but its induced in the submandibular glands a hypertrophy of the ductal component mainly in relation to the granular component.
Resumo:
Study of the epithelial morphology of a stingless bee ileum from the pyloric valve to the last portion of high absorptive cells shows that although the bee ileum is an anatomically undifferentiated tube, four types of epithelial cells along the tube (in addition to the valve cells) indicate physiological differentiation. The anterior end seems to be less active in reabsorption, while the posterior region contains cells with typical morphology of an ion pump and permits conclusions about the mechanisms of absorption in the posterior end of the intestine. (C) 1994 Wiley-Liss, Inc.
Resumo:
We report a rare heterotopic gastrointestinal cyst located in the right submandibular/submental area with histopathologic features that included portions resembling a dermoid cyst. Some theories of pathogenesis are discussed, and an origin of this lesion in entrapped undifferentiated endodermal cells is suggested.
Resumo:
A histological study was conducted on the testes of adult domestic quails (Coturnix coturnix japonica) over a year. The results revealed a clear variation of testicular weight, seminiferous tubule diameter, and the thickness and composition of the germinal epithelium over the year. The highest testicular weights were detected at the end of the autumn and during the winter (short-day period), reaching a maximum, together with spermatogenic activity, in September (long-day period in the southern hemisphere). In contrast, both testicular weight and spermatogenic activity were markedly decreased at the end of spring and during summer (long-day periods in the southern hemisphere).
Resumo:
Reproductive strategy is the set of adaptations that promote the most efficient way that the species will survive under the particular conditions of a determined environment. Understanding these adaptations is important and can help pinpoint populations indicator of environmental changes. Spermatogenesis is a measurable biological process of these adaptations in spatial and temporal scales. We analyzed the morphology of the testes and oviducts of the lizard species that comprise the genus Tropidurus, taking into account the geographical distribution and sympatric relations. For the analysis and the testes were removed from the middle part of the oviducts from Tropidurus etheridge, T oreadicus, T itambere, T spinulosus and T Guarani species, collected in different places in the Mato Grosso state, Brazil. The reproductive period is synchronous for males and females and occurs in September, October and November. Reproductive males were characterized. In the testes are seminiferous tubules with germ cells at different stages of spermatogenesis, with a high epithelium, at present light, free spermatozoa in the lumen and reduction of interstitial tissue. For females, the reproduction peak occurs when the oviduct epithelium is high with secretions and basal nucleus. These months are characterized in the sampled areas over a period of heavy rain and high temperatures. The decline of reproductive period was observed in both sexes, between April and August. Low reproduction in males is characterized by ample light, absence of sperm, only germ cells in the early stages of spermatogenesis are observed (a few spermatogonia and spermatocytes) and interstitial tissue wide. In females, the period of reproductive decline is marked by the absence of unicellular glands in the oviduct epithelium, with higher affinity with the dye. This period corresponds to low rainfall periods and lower temperatures. We propose an analysis of zoological samples; this is a proposal to facilitate the work of many researchers through access to the species, especially rare species.