Dental Assistant Practice Exam

Which part of the tooth is responsible for transmitting pain and sensitivity?

1. Dentinal tubules

2. Enamel

3. Clinical crown

4. Cemento-Enamel Junction

The correct answer is: Dentinal tubules

The part of the tooth responsible for transmitting pain and sensitivity is the dentinal tubules. These tubules are microscopic channels within the dentin layer of the tooth that extend from the pulp chamber to the outer layer of the tooth, allowing for the communication of sensations between the pulp and the external environment. When stimuli such as heat, cold, or pressure affect the dentin, they can transmit signals through the fluid within these tubules to the nerves in the pulp, resulting in the sensation of pain or sensitivity. In contrast, enamel primarily serves as the protective outer layer of the tooth and is not involved in sensation. The clinical crown refers to the visible portion of the tooth above the gum line, and while it contributes to the tooth's aesthetics and function, it does not transmit pain. The cemento-enamel junction is the area where the cementum (a bone-like substance covering the root) meets the enamel, but this junction also does not play a role in sensing pain or sensitivity. Thus, the dentinal tubules are uniquely equipped for this function due to their structure and connection to the pulp.