The morphology and development of intestinal folds and villi in vertebrates
The morphology and development of intestinal folds and villi in vertebrates
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DOI：
10.1002/aja.1000010406
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发表时间：
1902-09-01
影响因子：
--
通讯作者：
Hilton, WA
中科院分区：
文献类型：
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作者：
Hilton, WA
方法：为了获得正常形态的皱襞和绒毛，必须采用固定方法，不能使粘膜肌层的肌纤维收缩而产生异常形态。通常，在组织不再受刺激之前，肠就被注射并置于硬化液中，因此几乎任何快速作用的固定液都是不可取的。虽然福尔马林作用迅速，但发现它非常令人满意，因为绒毛的吸引力只有轻微的扭曲，但当要保存更精细的结构元件时，它就不那么有用了。米勒液或3%重铬酸钾溶液对保存绒毛效果很好，因为这些液体的作用很慢，绒毛很少收缩;但当这些液体被腐蚀时，上皮通常脱落。有时候，较高比例的酒精作为防腐剂是有效的，因为作用并不迅速。在固定液或酒精中硬化inteztines后，在火棉胶中切割相当厚的切片;切片的厚度取决于待检查的绒毛的大小。在液体下检查整个肠道通常有助于确定褶皱或绒毛的特征。当肌肉被膜足够薄时，肠段被盐酸胭脂红染色，粘膜隆起。当这是不可能的，绒毛进行了检查，已通过刮或切割粘膜分离。为了计数和测量褶皱和绒毛，使用了各种方法。最令人满意的，但并不总是适用的方法是通过一个正方形的目镜测微计。当绒毛非常多，肠壁很厚时，通过去除一小块粘膜并从中分离绒毛来计数它们，计数它们的尖端或基部，直到通过重复试验获得一致的结果。在每种情况下，都用尽可能多的不同方法研究肠道，并对结果进行比较。以下是每个样本通常使用的方法列表：
METHODS.In order to obtain folds and villi in their usual form, fixation must be used which will not cause the muscular fibers of the muscularis mucosle to contract and so produce unusual shapes. The intestines were usually injected and placed in the hardening fluids before the tissues had ceased to be irritable, so almost any of the fixing fluids which are rapid in their action were not desirable. Although formalin acts quickly, it was found to be very satisfactory, as the villi appeal only slightly distorted, but it was not so useful when the finer structural elements were to be preserved. Miiller’s fluid, or a solution of 3 per cent dichromate of potash, does very well for preserving villi, in that the action of these fluids is slow and villi are seldom contracted; but when these fluids are empicyed, the epithelium is usually exfoliated. At times a rather high percentage of alcohol was efficient as a preservative, as the action was not rapid.After hardening the inteztines either in the fixing fluid or in alcohol, rather thick sections were cut in collodion; the thickness of the sections depending upon the size of the villi to be examined. Examinations of the whole intestine under liquids often helped to determine the character of folds or villi. When the muscular coats were thin enough, bits of intestine were stained with hydrochloric acid carmine, and mounted mucosa up. When this was not possible, villi were examined which had been isolated by scraping or cutting from the mucosa. For counting and measuring folds and villi, various methods were used. The most satisfactory, but not always applicable, method was by means of an ocular micrometer in squares. When villi were very numerous and the walls of the intestine thick, they were counted by removing a measured bit of mucous membrane and isolating the villi from it, counting their tips or bases until by repeated trials, uniform results were obtained. In every case the intestines were studied by as many different methods as possible and the results compared. The following is a list of the methods ordinarily used for each specimen: