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Lab 2 Epithelial Tissue: Index - 1)Introduction - 2)Simple Squamous - 3)Simple Cuboidal - 4)Simple Columnar - 5)PsuedoStratified - 6)Transitional - 7)Stratified Squamous - 8)Stratified Columnar - 9)Stratified Cuboidal - 10) Trachea and Esophogus Comparison - 12) Practical |
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. SIMPLE CUBOIDAL EPITHELIUM In vertical section cells generally appear to be nearly square with nuclei approximately central. |
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1). distal and collecting tubules of kidneys # 141 - Kidney (pelvis & ureter), longitudinal section If needed, # 220 - Kidney, median sagittal section, h&e |
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See page 585 of Ross for orientation. Examine the slide by eye first to see the outer part of the bean-shaped kidney (the cortex) and the inner part (the medulla). This slide shows the one papilla of the unilobar rat kidney which points into the pelvis or "basin" of the kidney. In the middle region (the paler medulla ) look for the pale-staining simple cuboidal cells that make up the relatively straight collecting tubules. These have clear cell outlines, with obvious borders between adjacent cuboidal cells. In the renal cortex locate other examples of simple cuboidal epithelium. Locate a renal corpuscle (a glomerulus encased in a Bowman's capsule) and note that there are tubules surrounding it. In cross section these tubules appear as daisy-shaped structures. The proximal tubules are eosinophilic (pink-staining) with an indistinct lumen (since they have a brush border of microvilli). The paler distal tubules are smaller in diameter than the proximal tubules but have a larger lumen (they have no brush border). References:Gartner, p. 325, Fig. 3 (proximal, distal, and collecting tubules) p. 32, Fig. 2 (collecting tubules) p. 327, Fig. 1 - 3 (proximal and distal tubules) p. 331, Fig. 2 and 4 (collecting tubules) (Ross, pp. 586 - 587, Fig. 1 - 2) (Wheater, p. 78, Fig. 5.2 (collecting tubules) pp. 588 - 589, Fig. 1 - 4 p. 300, Fig. 16.20 (collecting tubules) pp. 591, Fig. 1) (DiFiore, p. 249, Fig. 16.2 collecting tubules ) |
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The green arrows are pointing to the simple cuboidal cells of the collecting tubules. Notice how they are as tall as they are wide. Cells with that characteristic are usually characterized as simple cuboidal. Can you guess what the white arrow is pointing to? It is pointing to a squamous endothelial cell lining a blood vessel. Notice the deference between the two cells. Hint: If you see Red Blood Cells it is probably a blood vessel. |
Collecting tubules (kidney) Green Arrow - Simple Cuboidal Cells White Arrow - Endothelial Cell of Blood Vessel |
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2. follicular cells of the thyroid gland # 158 - Thyroid, human, h&e, 1.5 mm # 4 - Thyroid, simple cuboidal epithelium, h&e |
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This thin section (#158) through the thyroid gland has been embedded in plastic. Observe the simple cuboidal epithelium that lines many of the pink-staining follicles. The state of activity of the follicle affects the height of the epithelium. Therefore, some follicles may have a flattened epithelium (relatively inactive follicles) and some may have a columnar epithelium (hyperactive follicles). See Slide #4 to note that flattened epithelium may be found in some thyroid follicles. References: (Gartner, p. 209, Fig. 2) (Ross, p. 629) ( DiFiore, p. 269, Fig. 17-5, 17.6) (Wheater, p. 310, Fig. 17.) |
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Thyroid follicles are very easy to identify. Nothing else in histology looks like what the thyroid colloid (the red stuff surrounded by cells) looks like. So if you see anything that looks like this, you are in the thyroid. Hint: The cells may look flat, but they are simple cuboida (green arrow)l. (this is one you just have to remember) |
Thyroid Gland Green Arrow - Simple Cuboidal follicular cells |
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