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An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal

The structure of the intestinal villus of the rat was studied in thin sections of tissue fixed in buffered osmium tetroxide and embedded in methacrylate. The simple columnar epithelium investing the villus is surmounted by a striated border consisting of slender projections of the cell surface. Thes...

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Detalles Bibliográficos
Autores principales: Palay, Sanford L., Karlin, Leonard J.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1959
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2224666/
https://www.ncbi.nlm.nih.gov/pubmed/13664676
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author Palay, Sanford L.
Karlin, Leonard J.
author_facet Palay, Sanford L.
Karlin, Leonard J.
author_sort Palay, Sanford L.
collection PubMed
description The structure of the intestinal villus of the rat was studied in thin sections of tissue fixed in buffered osmium tetroxide and embedded in methacrylate. The simple columnar epithelium investing the villus is surmounted by a striated border consisting of slender projections of the cell surface. These microvilli are arranged in almost crystalline, hexagonal array, and increase the apical surface area of the cell by a factor of 24. The core of each microvillus is filled with fine fibrils which arise from the filamentous substance of the terminal web underlying the striated border. Each microvillus is covered by a tubular extension of the plasma membrane of the epithelial cell. Pinocytotic vesicles originating from the plasma membrane occur at the bases of the intermicrovillous spaces. The nucleus, mitochondria, and the endoplasmic reticulum of the epithelial cell display no unusual features. Small bits of ergastoplasm occur in the apical cytoplasm. A thin basement membrane separates the epithelium from the lamina propria which consists of vessels, nerves, and numerous lymphocytes, eosinophiles, mast cells, plasma cells, smooth muscle fibers, and macrophages suspended in a delicate stroma of fibroblasts and collagen fibers. Intercellular fat droplets often occur in this stroma, even in animals fasted for 40 hours. The blood capillaries are distinguished by their extremely attenuated, fenestrated endothelial cells. The lacteal has a thicker endothelium which, although not fenestrated, appears to have significant interruptions, especially at the margins between neighboring lining cells. Strands of smooth muscle always accompany the lacteal but do not form an integral part of its wall. Unmyelinated nerves, many of which are too small to be distinguished with the light microscope, course through the lamina propria in association with the vessels. The nerve fibers evidently do not cross the basement membrane into the epithelium. Neuromuscular junctions or other terminal apparatus were not found.
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spelling pubmed-22246662008-05-01 An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal Palay, Sanford L. Karlin, Leonard J. J Biophys Biochem Cytol Article The structure of the intestinal villus of the rat was studied in thin sections of tissue fixed in buffered osmium tetroxide and embedded in methacrylate. The simple columnar epithelium investing the villus is surmounted by a striated border consisting of slender projections of the cell surface. These microvilli are arranged in almost crystalline, hexagonal array, and increase the apical surface area of the cell by a factor of 24. The core of each microvillus is filled with fine fibrils which arise from the filamentous substance of the terminal web underlying the striated border. Each microvillus is covered by a tubular extension of the plasma membrane of the epithelial cell. Pinocytotic vesicles originating from the plasma membrane occur at the bases of the intermicrovillous spaces. The nucleus, mitochondria, and the endoplasmic reticulum of the epithelial cell display no unusual features. Small bits of ergastoplasm occur in the apical cytoplasm. A thin basement membrane separates the epithelium from the lamina propria which consists of vessels, nerves, and numerous lymphocytes, eosinophiles, mast cells, plasma cells, smooth muscle fibers, and macrophages suspended in a delicate stroma of fibroblasts and collagen fibers. Intercellular fat droplets often occur in this stroma, even in animals fasted for 40 hours. The blood capillaries are distinguished by their extremely attenuated, fenestrated endothelial cells. The lacteal has a thicker endothelium which, although not fenestrated, appears to have significant interruptions, especially at the margins between neighboring lining cells. Strands of smooth muscle always accompany the lacteal but do not form an integral part of its wall. Unmyelinated nerves, many of which are too small to be distinguished with the light microscope, course through the lamina propria in association with the vessels. The nerve fibers evidently do not cross the basement membrane into the epithelium. Neuromuscular junctions or other terminal apparatus were not found. The Rockefeller University Press 1959-05-01 /pmc/articles/PMC2224666/ /pubmed/13664676 Text en Copyright © Copyright, 1959, by The Rockefeller Institute
spellingShingle Article
Palay, Sanford L.
Karlin, Leonard J.
An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal
title An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal
title_full An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal
title_fullStr An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal
title_full_unstemmed An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal
title_short An Electron Microscopic Study of the Intestinal Villus : I. The Fasting Animal
title_sort electron microscopic study of the intestinal villus : i. the fasting animal
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2224666/
https://www.ncbi.nlm.nih.gov/pubmed/13664676
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