Cervical Region 
Figure 3-21: Histology of tracheal epithelium, composed of pseudostratified cili- 
ated columnar type with goblet cells and a few basal cells, (l-^m-thick section; tol- 
uidine blue, X223). 
Figure 3-22: Histology of thyroid gland, demonstrating follicles filled with serous 
secretion and surrounded by flattened epithelial cells (H & E, X57). 
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