Cells and Tissues

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Covering and Lining Epithelia

a. Arrangement of cells in layer

b. Shapes of the cells

Arrangement ( 3 factors)

1. Simple: Single layer of epithelial cells

2. Stratified: two of more layers of cells

3. Pseudostratified: Appears to have multiple layers of cell but does not have multiple layers.

(A simple epithelial cell in disguise)

All the cells even though the nuclei are at different levels all the cells touch the basement membrane (not piled on like stratified cells).

Shape ( 4 types)

1. Squamous: Flat like pavement

2. Cuboidal: Cube chaped

3. Columnar: Rectangular

4. Transitional: Can change shape from Cuboidal to squamous

5 main combinations of arrangement and shape

Simple squamous Epithelium

A single later of flat cells

- For filtration

- Very delicate

- Looks like fried eggs

- Sometimes called mesothelium

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