Oral mucosa lamina propria

Figure 3.5. Structure of oral tissues. The mouth and esophagus are composed of two layers the mucosa and submucosa. The mucosa is composed of layers of squamous epithelium, lamina propria, and muscularis. The submucosa contains blood vessels, nerves, adipose tissue, and skeletal muscle.

A rich blood supply and lymphatic network in the lamina propria serve the oral cavity, thus drag moieties which traverse the oral epithelium are readily absorbed into the systemic circulation. The blood flow in the buccal mucosa is 2.4 mL min 1 cm 2 whereas that to the sublingual mucosa is 0.97 mL min-1 cm 2. 

Connective tissues consist of lamina propria and submucosa, if present. The lamina propria is a continuous sheet of connective tissue composed of blood capillaries and nerve fibers serving the oral mucosa. 

An 80-year-old Japanese woman presented with epigastric discomfort and nausea. She had a history of hypertension, rheumatoid arthritis, iron deficiency anemia, chronic renal insufficiency, and had taken oral ferrous sulfite for 19 months. Endoscopic examination of the duodenum showed marked pigmentation of the duodenal mucosa. Histological examination showed that the pigment had histochemical features compatible with hemosiderin and was located mainly within macrophage lysosomes in the lamina propria. Ferrous sulfite was withdrawn and the pigmentation disappeared within 7 months. 

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