第2章 上皮組織
Chapter 2 Epithelial tissue

No.6 單層扁平上皮 Simple squamous epithelium

大網膜鋪片，狗，銀染法 Spread preparation of omentum，dog，silver staining

取動物大網膜經硝酸銀浸染，剪成小塊平鋪于載玻片上而制成。用其觀察單層扁平上皮的正面形態結構。

選擇大網膜鋪成單層，且背景較清楚的部分觀察。

上皮細胞呈不規則形或多邊形，相鄰細胞之間有棕黑色的硝酸銀顆粒沉積。

細胞之間的硝酸銀顆粒較大且多，故著色深；胞質內的硝酸銀顆粒細小而分散。細胞核呈橢圓形，著藍色（蘇木素復染）。

In this preparation，the mesothelial lining of the peritoneal cavity has been stripped from the underlying connective tissues and spread onto a slide thus permitting a surface view of simple squamous epithelium.

Low and high power：Simple squamous epithelium（the mesothelium）is observed with surface view. The intercellular substance has been stained with silver outlining the closely interdigitating cell boundaries. The nuclei of the cells are centrally or eccentrically located, which have been stained with the dye，hematoxylin.

No.46 單層扁平上皮 Simple squamous epithelium

小腸，狗 Small intestine，dog，H&E

〔4倍物鏡〕呈指狀突起的一面為小腸黏膜，與其相對的另一面是小腸的腹腔面，被覆單層扁平上皮。

〔10倍物鏡〕在切片的邊緣有一條彎曲，且著淺紅色的細帶，為單層扁平上皮的側面觀，其內斷續的紫藍色的點狀結構，此即單層扁平上皮細胞核。選細胞核較多、排列較整齊的部位，換40倍物鏡進一步觀察。

〔40倍物鏡〕單層扁平上皮的側面觀，其細胞核呈扁橢圓形或卵圓形，胞核的長軸與上皮的表面平行。因上皮細胞呈薄片狀，故僅見胞核周圍少量的嗜酸性胞質。

Naked eye：The wave-like violet band is the intestinal mucosa. The opposite margin is the outer surface of the small intestine covered by the simple squamous epithelium，called mesothelium.

Low and high power：The mesothelial lining cells are so flattened that they can only be recognized by their nuclei which are basophilic and bulge into the lumen. The supporting basement membrane is very thin and can not be seen in this micrograph. In the underlying connective tissue，another type of simple squamous epithelium，called endothelium，can be found to line some small blood vessels.

No.46 單層柱狀上皮 Simple columnar epithelium

小腸，狗 Small intestine，dog，H&E

〔4倍物鏡〕這是空腸的縱切面組織切片，平坦的一邊是空腸的外表面，即腹腔面；有大小指狀突起的一邊是空腸的內表面，即腸腔面，其表面被覆單層柱狀上皮。

〔10倍物鏡〕指狀突起表面所被覆的組織是單層柱狀上皮，細胞核呈長橢圓形或桿狀，眾多的細胞核緊密排列成一層。有些部位的上皮細胞核聚集成堆或排成多層，此因該處眾多的上皮細胞被斜切所致。少數細胞核上部的胞質呈圓形或橢圓形空泡狀，該細胞為杯狀細胞。選擇細胞核排列成單層的部位，換40倍物鏡觀察。

〔40倍物鏡〕小腸單層柱狀上皮的游離面有一條紅色的帶狀結構，稱紋狀緣。柱狀的上皮細胞緊密排列成一層，細胞間的界限有的不清楚。但是，可根據細胞核呈長橢圓形或長桿狀，并排列為一排，即可推斷該上皮是由單層的柱狀細胞組成（一般而言，細胞核的形態是與該細胞的形狀相對應的）。細胞核的長軸與細胞的長軸一致，偏居細胞的基底部。柱狀的上皮細胞間可見杯狀細胞，其外形似高腳酒杯，細胞核上部的胞質內，有個圓形或橢圓形的空泡區（此因該處胞質內的黏原顆粒在制片過程中被溶解，致使顆粒所在區著色很淺）；細胞游離面的紋狀緣中斷；細胞核常呈三角形或桿狀，著深藍色，位于細胞基底部。

Naked eye：The violet band is the intestinal mucosa.

Low power：Find out finger-like projections（villi）on the mucosa side. The surface of villi is covered by simple columnar epithelium, in which tightly compacted nuclei can be seen in one layer.

High power：Two kinds of cells are present in this epithelium. Columnar cell has an oval nucleus with its long axis paralleling to the long axis of the cell. The luminal plasma membranes of columnar cells are often arranged into numerous，minute，finger-like projections called microvilli which are too small to be resolved individually. But the microvilli collectively give the appearance of a striated border at the luminal surface. Between the columnar cells，goblet cell is irregularly distributed and shows a vacuole feature with a dark nucleus below the vacuolar cytoplasm.

No.54 假復層纖毛柱狀上皮 Pseudostratified ciliated columnar epithelium

氣管，人 Trachea，human，H&E

〔4倍物鏡〕氣管橫切面的組織切片，呈半環形或環形，凹面（氣管腔面）被覆假復層纖毛柱狀上皮。

〔10倍物鏡〕沿氣管腔面觀察，假復層纖毛柱狀上皮的細胞核密集排列成數層，染成藍色。選擇層次結構較清晰的部位，換40倍物鏡觀察。

〔40倍物鏡〕上皮細胞界限不清，游離面有呈簇或成排的淺紅色細絲，即纖毛。纖毛所在的細胞，為纖毛細胞，呈柱狀，該細胞上半部呈柱狀，下半部纖細；細胞核呈橢圓形，位于多層上皮細胞核的淺層。纖毛細胞間常有杯狀細胞。深層的細胞核多呈圓形，胞質甚少且不清楚，此即錐體形細胞。其他的細胞多數是梭形細胞，細胞核圓形，位于成層排列的胞核的中間層。常見浸入上皮內的小淋巴細胞，其核小而圓，著色很深。上皮基部的基膜，著淡紅色，呈細線狀，有時不明顯。

Naked eye：The inner surface is purple and lined with epithelium.

Low power：The term pseudostratified is derived from the appearance of this epithelium in section which conveys the erroneous impression that there is more than one layer of cells. This，however，is a true simple epithelium since all the cells rest on the basement membrane，although not all the cells extend to the luminal surface. The nuclei of these cells are disposed at different levels，thus creating the illusion of cellular stratification.

High power：There are approximately 3 layers of nuclei showing a stratified appearance. The upper nuclei belong to columnar cells whose free surface has a lot of cilia. The nuclei of fusiform cells are in the middle. The nuclei at the bottom just above the obvious basal membrane are nuclei of pyramidal cells. Goblet cells are also present. The columnar cells and goblet cells reach the surface.

No.43 未角化復層扁平上皮 Nonkeratinized stratified squamous epithelium

食管，人 Esophagus，human，H&E

〔4倍物鏡〕為橫切的食管組織切片，管腔不規則，近腔面紫紅色的彎曲環帶為未角化復層扁平上皮。

〔10倍物鏡〕食管腔面的未角化復層扁平上皮，細胞層次多，各處厚薄不一。基底層的細胞胞質呈強嗜堿性，趨向上皮淺表層，細胞質呈嗜酸性。上皮的基部起伏不平，在其深部，染淺紅色的結締組織呈指狀或乳頭狀突入上皮。

〔40倍物鏡〕淺層的上皮細胞呈扁平狀或鱗片狀，胞質著淡紅色，胞核小，呈扁圓形，與上皮表面平行。中間層的上皮細胞呈多邊形，細胞界限較清楚。豐富的胞質呈嗜酸性，胞核呈圓形或卵圓形。基底層的上皮細胞為矮柱狀，胞核呈橢圓形；細胞質少，強嗜堿性。上皮的基部，有薄層的嗜酸性基膜，不明顯。

Naked eye：The purple line placed on the lumen side of this organ is epithelium.

Low power：The epithelium is composed of many layers of cells which undergo morphological transition from the cuboidal basal layer to the extremely flattened surface layers. The junction between epithelium and underlying connective tissue is usually irregular. The projection of connective tissue into the epithelium is called dermal papillae.

High power: Note the highly cellular basal layer and the transition from the large polygonal cells of the intermediate layers to the superficial squamous cells.

No.60 變移上皮 Transitional epithelium

膀胱，空虛狀態，狗 Bladder，non-distended state，dog，H&E

〔4倍物鏡〕此為空虛時膀胱的切片，膀胱的外表面被覆單層扁平上皮，內表面即腔面被覆變移上皮。

〔10倍物鏡〕變移上皮較厚，上皮細胞層次多，表層的細胞體積大，上皮基底面與結締組織交界處較平坦。

〔40倍物鏡〕自上皮的表層向基底層方向順次觀察。表層的細胞體積大，呈立方形或長方形；細胞核呈圓形或橢圓形，有的細胞含兩個細胞核；細胞質豐富，嗜酸性，著色較紅。中間層的細胞呈倒梨形，細胞核呈圓形。基底層的細胞核呈卵圓形或圓形。變移上皮與結締組織之間有基膜。

Naked eye: The purple line placed on one side is transitional epithelium. The other side is covered by simple squamous epithelium.

Low Power：Several layers of cells are situated on the basement membrane.

High Power：The shape and size of the basal and intermediate cells vary considerably depending on the degree of distension，but the cells of the surface layer usually retain several characteristic features. In this “relaxed” state of the epithelium，basal and intemediate cells have a cuboidal or columnar shape. The surface cells are large and pale-stained and present a scalloped suface outline. The nuclei of the surface cells are large，round，sometimes binucleated, and often exhibit prominent nucleoli.