Speech Pathology How We Swallow

Swallowing is an essential part of life that we rarely pay any attention to, until there is a problem.

Disorders of swallowing are called Dysphagia: (Dis-fay-gee-ah). Dysphagia may arise from a variety of origins. These may include head injury and neurological impairment, Stroke, a range of progressive neurological disorders or age related changes.

Swallowing is considered to be both an autonomic and dynamic action, that involves a number of cranial nerves that initiate action and sequential movement patterns in a variety of muscle groups. Any weak link in this complex chain of movement and support structuring of reflex and movement, will result in Dysphagia and the potential for choking or aspiration of food or fluids into the lungs.

The 4 Stages of Swallowing

The process of swallowing occurs in four stages:

• Oral Preparation stage, in which food or liquid is anticipated and received in the anterior (front) of the mouth in preparation for chewing and eventual swallowing.
• Oral Propulsive stage, in which we chew the foodstuffs, formulate a bolus of food or fluid and transit

the bolus to the back of the mouth, initiating the swallowing reflex.

• Pharyngeal stage, in which the swallow is initiated and the food or liquid quickly passes through the pharynx (the canal from the mouth to the esophagus) into the esophagus. The airway is closed and secured by the epiglottis folding over the entrance of the larynx, the closure of the vocal cords and the elevation of the laryngeal structure to effect total closure.
• Oesophageal stage, in which the food or liquid moves via the relaxation of the cricopharyngeus muscle and with the peristaltic assistance of the pharyngeal constrictors, through the esophagus and esophageal sphincter and into the stomach.

The first two steps are controlled voluntarily, while the latter two steps occur involuntarily. The process involves rapid, precise coordination of numerous muscles and tissues of the mouth, pharynx, larynx and esophagus. Any disturbance to this process results in Dysphagia.

Cranial Nerves Involvement and Action

The 5^th cranial nerve: Trigeminal, located at the Pons level of the brainstem, contains both sensory and motor fibres and pathways that innervate the face. It is important in chewing and bolus formation.

The 7^th cranial nerve: Facial nerve has 3 branches and contains both sensory and motor fibres and pathways.

It is important for lip closure and seal and also the sensation of the oropharynx and taste to anterior (front) 2/3 of the tongue.

The 9^th cranial nerve: contains both sensory and motor fibres and pathways. It is important for taste to the posterior 1/3 of the tongue and also the sensory and motor functions of the pharynx (throat)

The 10^th cranial nerve: Vagus nerve contains both sensory and motor fibres and pathways. It is important for taste to the oropharynx and sensation and motor function to the larynx and laryngopharynx (lower throat), necessary for airway protection.

The 12^th cranial nerve: Hypoglossal, contains motor fibres and pathways to innervate the tongue.

Evaluation of Swallowing Problems

If you or your loved one are experiencing difficulties with feeding and swallowing please contact us or your medical professional straight away.

Your medical consultant can examine you and address any medical reasons for the swallowing difficulties, including the presence of reflux or metabolic disorder. Melbourne Speech and Swallowing Clinics who specialise in treating children and adults with feeding and swallowing disorders, can evaluate you and will:

• Take information regarding your medical history, development, symptoms and current feeding regimes and oral diet.
• Assess the bulbar musculature; that is the groups of muscles responsible for maintaining a competent swallow.
• Assess the array of reflexes that should be present to assist in the initiation of a swallow and the protection of the airway.
• Observe a feeding/ swallowing session to assess your or your child’s posture and positioning, behaviour, oral, pharyngeal functioning and respiratory competency.
• Advise and counsel you as to any functional changes that can be made to encourage a more competent swallow and improve overall patterning, competence and confidence.
• Perform special tests, if necessary, to evaluate swallowing competency.

Please contact us for professional advice if you have any concerns regarding feeding or swallowing issues.

Mr Craig Gorman

Speech Pathologist

Melbourne Speech Clinics

T: 1300 654 540

M: 0412515325