Diagrams swallowing act and FEES

Design of two diagrams on healthy and impaired swallowing and on the standard protocol for an FEES examination.


The act of swallowing is a complex physiological process in which food or liquid passes from the mouth into the stomach. It involves a series of coordinated muscular movements in the mouth, throat and esophagus. Initially, the food lump is broken up by chewing movements in the mouth and mixed with saliva, which facilitates the swallowing process. The food bolus is then pushed through the pharyngeal muscles towards the oesophagus, whereby the larynx is closed with the epiglottis to prevent food from entering the windpipe. The esophageal muscles contract rhythmically and push the bolus of food into the stomach. The act of swallowing normally occurs automatically and without conscious effort, but is impaired in the event of swallowing disorders such as difficulty swallowing or dysphagia.

To diagnose such disorders, a flexible endoscope with a light source and a camera is inserted through the nose and placed in the throat. This method is known as FEES – which stands for “fiberoptic endoscopic evaluation of swallowing”. This examination allows the doctor to observe the act of swallowing in real time by looking at the movements of the throat muscles, the transportation of food or liquid and possible signs of aspiration (penetration of food or liquid into the airways).

Project description

We designed two diagrams for a medical textbook on the subject of dysphagia – one on the standard protocol for a FEES examination and one on the phases of the swallowing act. For this purpose, we created around 32 illustrations of the healthy process and pathological disorders in the style of FEES images. Due to the large number of illustrations in the diagrams, they were designed in a style that is as striking and easy to “read” as possible.

The first diagram focuses on normal (healthy) results of an FEES examination and compares them with pathological changes or disorder patterns in the process. The pathological FEES findings shown are velum paresis, unilateral/bilateral vocal cord paresis, missing/delayed conversion, pharyngeal paresis, weakened tongue base retraction, closure of the glottis, irregular arytenoid movements.

The second diagram shows the different phases of a swallowing act (oral preparation phase, oral phase, pharyngeal phase, oesophageal phase). Illustrations in the style of FEES images are shown, which compare the healthy swallowing process with various pathological findings. The following disorders were discussed: Prolonged/shortened oral bolus preparation, Impaired oral bolus control with leaking, Delayed swallowing reflex, Delayed laryngeal reconfiguration, Decreased epiglottis inversion, Postdeglutitive residuals on the pharyngeal wall, Postdeglutitive residuals in the piriform sinuses, Postdeglutitive residuals in the valleculae, Attenuated/prolonged white-out, Prolonged epiglottis inversion.

Project details Swallowing act and FEES diagrams

Content: 2 diagrams – 32 illustrations

Use: Medical textbook

Specs: DIN A5

Client: Dr. Dziewas, Dr. Warnecke, Universitätsklinikum Münster

The rights of use of the images shown here are held by the client; use is not permitted. Images are protected by watermarks. Illustration in sagittal section by Heike Blum.

Illustrations deglutition
FEES illustrations – detail view