The tongue is a movable organ in the mouth, mainly composed of muscles that can change its position.
The tongue is covered with a large number of papillae, which allow humans to taste different flavors such as sour, salty, sweet, and bitter.
Functions of the Tongue
Functions of the tongue include:
- Chewing: A process in the mouth where food is ground up by the teeth, mixed with saliva and enzymes, and then swallowed to be further digested in the stomach.
- Swallowing: The process of moving food or drink from the mouth, through the throat, and into the esophagus. The epiglottis, windpipe, and uvula close off the nasal passage during swallowing.
- Tasting: The ability to perceive certain chemical compounds as flavors.
- Cleaning: The process of cleaning the teeth.
Rules for the Tongue in Passport Photos
Rules for the tongue in passport photos state that it should not be visible. The guidelines require a neutral expression with the mouth closed to ensure optimal recognition.
An open mouth may distract from the facial features and disrupt the required neutral expression.