Swallowing

Have you ever felt like food was “getting stuck in your throat” when you were trying to swallow? Or do you experience frequent coughing after drinking liquids? The processes of chewing and swallowing involve the coordination of many structures and muscles! A general understanding of the anatomy and physiology of “normal” swallowing is key to understanding what types of problems might arise and how to resolve those problems.

Here is a general overview of the structures involved in swallowing and what happens during the three “phases” of swallowing :

• Oral Phase: Structures include: lips, mouth tongue, teeth, jaw movement - In this phase the food or liquid is prepared for swallowing. The lips seal tightly to prevent food or liquid from leaking out of your mouth, food is chewed and mixed with saliva to form a soft, uniform consistency, and the tongue moves the food around in your mouth for chewing and then moves the food or liquid towards the back of the mouth in preparation for swallowing. While this process may sound simple, this phase is very important and requires complex muscle coordination to prepare the food adequately and safely (no fun to bite your tongue!) and to move it efficiently to the back of the mouth where the next phase begins.

• Pharyngeal Phase: Structures include: soft palate, muscles of the throat (pharynx), epiglottis, larynx, vocal cords - When the food moves to the back of the mouth it touches structures and areas that trigger a “swallow reflex”. The “swallow reflex” involves the coordinated movement of many muscles and structures in the back of the mouth and the throat as well as the coordination of breathing and swallowing. While this process typically occurs reflexively, it is possible to execute some of the movements voluntarily. Breathing stops as the vocal cord close, the larynx is pulled upwards, and the epiglottis moves to cover the larynx in order to prevent the food/liquid from entering the airway. At the same time, the esophagus is pulled open and the food/liquid is squeezed down the pharynx (throat) and into the esophagus. And, when everything is working correctly, all this takes place in less than 1 second… and we do this 500-700 times every day!

• Esophageal Phase: Structures include: Muscles of the esophagus (upper and lower sphincter muscles), constrictor muscles - This phase is involuntary and consists of muscle movement pushing the food/liquid down the esophagus and into the stomach.

What can go wrong?

A disruption to any aspect of the complex coordination of muscle movements, structure integrity, or muscle weakness can contribute to swallowing difficulties or “dysphagia”. Examples of injuries and/or disease processes that can affect swallowing function include:

• Head & Neck Cancer - Surgery or radiation may injure neural pathways controlling the muscles involved in swallowing, or may require removal of a structure that is critical to safe swallowing.

• Neurodegenerative diseases affecting muscle control - Diseases like Parkinson’s Disease or Progressive Supranuclear Palsy often disrupt the body’s ability to control muscle movement or cause muscle weakness. Coordinated muscle movement and adequate muscle strength are essential for for safe swallowing.

• Stroke/Traumatic Brain Injury - Strokes and TBIs cause brain injuries that are specific to regions of the brain affected by the trauma or restricted blood supply. Injuries that occur in regions of the brain that facilitate muscle movement or coordinaton of movements may result in difficulty swallowing safely.

Contact our clinic today to learn more about services we offer to help you swallow safely and to schedule a free consultation appointment.

Swallowing Studies:

Because swallowing happens inside structures of the body, it can be difficulty to know where a problem is occurring without being able to “see” inside the body in some way. Below are videos demonstrating two types of “instrumental swallowing studies” that are commonly used when a person is having difficulties swallowing safely.

The first video demonstrates a Fiberoptic Endoscopic Evaluation of Swallowing (FEES) swallowing study. During a FEES swallowing study, a special camera is inserted through the nose in order to watch patients’ swallow and assure that muscles in the throat are working properly. See if you can identify these structures: The base of the tongue, the epiglottis, the larynx and the vocal cords.

This second video show another type of swallowing study, a Videofluoroscopic Swallowing Study (VFSS), sometimes called a Modified Barium Swallow Study. This type of swallowing study uses x-ray imaging to view the swallow. Different structures and swallowing phases are visualized more easily in different types of swallow studies.