Practical classes 1: Covering epithelium
Osnova sekce
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Supported by the project: Zvýšení kvality vzdělávání na UK a jeho relevance pro potřeby trhu práce
Registration number: CZ.02.2.69/0.0/0.0/16_015/0002362
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.This electronic course provides basic information for a self-study of histological slides of covering epithelia. Correct identification of epithelia is a key prerequisite for differential diagnosis of histological slides.
Knowledge of this topic and these slides is required in slide tests, credits and final examination in histology and embryology.
Epithelium
Epithelial cells are part of epithelial tissues. According to their arrangement, they are classified as: the surface epithelium, which lines the inner and outer surfaces of the body, the trabecular epithelium, whose cells form three-dimensional strands, and the reticular epithelium, whose star-shaped cells are connected by their cytoplasmic protrusions into a three-dimensional network. According to their function, covering, glandular and special epithelia are distinguished.
Characteristics of covering epithelia
The covering epithelium falls under the surface epithelium. Their cells are connected by intercellular contacts, so that they closely adhere to each other (the space between the cells almost contains no extracellular matrix). The basal layer of epithelial cells is anchored to the basal lamina, which separates the overlying epithelium from the adjacent connective tissue. Epithelia are avascular; their nourishment occurs through the basal lamina. Epithelial cells are polarized, i.e. their surfaces differ morphologically (basolateral and apical surfaces have different roles), reflecting the functional specialization of the cells. Different organs performing diverse functions are lined by different covering epithelium. Correct identification of the epithelium allows both the diagnosis of the organ and the determination of its function. For the classification of covering epithelia it is essential:
- to determine the number of layers or rows of epithelial cells;
- to determine the shape of the superficial (i.e., the most specialized) cells;
- to define the relationship of uppermost cells to the basal lamina.According to the number of layers/rows, covering epithelia are divided into simple, pseudostratified and stratified.
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Description of microscopic structure and examples of simple epithelia.
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Interpretation of microscopic structure and examples of pseudostratified epithelia.
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Microscopic structure and examples of stratified epithelia.
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Electronic course contains also material for printing and a test for a self-study.
References:
Junquiera, L. C., Carneiro, J. Basic Histology. Text and atlas. 11th ed. McGraw-Hill, New York, 2005, 502 pp.
Krstic, R. V. General Histology of the Mammal. Springer-Verlag, Berlín, 1985, 404pp.
Mascher A. L.. J. Junquiera's Basic Histology. Text and atlas. 13th ed. McGraw-Hill, New York, 2013, 544 pp.
Mokrý, J., Mazurová, Y., Mráz, J., Čížková, D., Hrebíková, H., Soukup, T. Handbook of Practical Classes in Histology and Embryology, Powerprint, Prague, 2017, 136 pp.
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