The Pharyngeal Stage

This is the first involuntary stage of swallowing. This is a 1 second process when the bolus comes in contact with the faucial arches. Within this stage the soft palate elevates, vocal cords adduct, respiration pauses, the larynx elevates, and lastly the cricopharynxgeus relaxes.

Soft Palate Closure 

The closing of the soft palate prevents food and liquid from going into the nasal cavity. 

There are 5 muscles that are involved in soft palate movement:

• Levator Veli Palatini (Cranial Nerve X & XI) raises the soft palate 
• Palatoglossal (Cranial Nerve X & XI) raises the soft palate
• Tensor Veli Palatini (Cranial Nerve V) tenses soft palate 
• Musculus uvulae (Cranial Nerve X & XI) closes off soft palate
• Palatopharyngeus (Cranial Nerve X, XI) pulls up and constricts pharynx

Laryngeal Closure and Elevation

3 valves close to protect the airway from the bolus entering it 

1. Epiglottis–Valve 
2. False vocal cords–Valve
3. True vocal cords (CN X)

Many suprahyoid muscles contract to raise the larynx under the closing epiglottis and further seal off the airway, protecting it from the bolus

Pharyngeal Constriction

Superior pharyngeal constrictor, Middle pharyngeal constrictor, Inferior pharyngeal constrictor are controlled by CN X and XI