Describe the mechanisms that prevents food from entering the nasal cavity and larynx during swallowing
When we swallow food, our body has several mechanisms in place to prevent it from entering the nasal cavity and larynx. These mechanisms include:
1. Soft Palate Closure: The soft palate, also known as the velum, is the tissue at the back of the roof of the mouth. During swallowing, the soft palate elevates and moves backward to close off the nasal cavity, thus preventing food from entering it.
2. Epiglottis: The epiglottis is a flap of tissue located at the base of the tongue. It serves as a protective cover for the larynx, which leads to the trachea (windpipe). When we swallow, the epiglottis folds down over the opening of the larynx, directing food away from the airway and into the esophagus.
3. Pharyngeal Constrictor Muscles: The pharynx, or throat, is a muscular tube that connects the mouth to the esophagus. During swallowing, the pharyngeal constrictor muscles contract sequentially, creating a wave-like motion that propels the food downward. This coordinated contraction also helps to close off the entrance to the larynx, preventing food from entering it.
4. Vocal Cord Closure: The vocal cords are located within the larynx and are responsible for producing sound. During swallowing, the vocal cords close tightly to prevent food or liquid from entering the airway.
All of these mechanisms work together to ensure that food passes smoothly from the mouth into the esophagus, while protecting the nasal cavity and larynx from any ingested material.