National Board Dental Hygiene Examination (NBDHE) Dental Hygienist Practice Test

Which type of epithelial tissue is found lining the oral cavity?

1. Stratified squamous

2. Simple squamous

3. Stratified columnar

4. Simple columnar

The correct answer is: Stratified squamous

The lining of the oral cavity is composed of stratified squamous epithelial tissue. This type of epithelial tissue consists of multiple layers of cells, with the outermost layers being flattened (squamous) cells. This arrangement offers protection against mechanical irritation, abrasion, and potential pathogen invasion, which are common in the oral cavity due to activities like chewing and speaking. Stratified squamous epithelium is particularly well adapted for the oral environment because it can withstand the wear and tear that occurs in this area. Additionally, the presence of multiple layers helps to provide a barrier to harmful substances and microorganisms. The other types of epithelial tissue listed do not suit the functional requirements of the oral cavity. Simple squamous epithelium, while thin and capable of diffusion and filtration, lacks the protective qualities necessary in the oral environment. Stratified columnar and simple columnar epithelia are less common in the oral cavity and are usually found in specific locations such as parts of the gastrointestinal tract and some glandular ducts, where different functional roles are needed. Thus, the correct identification of stratified squamous epithelium highlights its unique protective function in the highly functional and variable environment of the oral cavity.