CDIS module 7

3 major salivary glands

Parotid, sublingual, submandibular

Swallowing central pattern generator

Dorsal Swallowing Group (DSG) and Ventral Swallowing Group (VSG)

Dorsal Swallowing Group

Sets the pattern

• Located near the solitary tract nucleus

• Generates the swallowing pattern

• Sends output to the hypoglossal nucleus

Ventral Swallowing Group (VSG)

Executes the pattern

• Located near the nucleus ambiguus

• Carries out the swallowing plan

• Gets sensory input from CN V, IX, and X

 IDDSI Levels 3–6

Level 3 → Liquidised
Level 4 → Pureed
Level 5 → Minced & Moist
Level 6 → Soft & Bite-Sized

During the pharyngeal swallow

The velum elevates to close off the nasal cavity, larynx elevates, epiglottis inverts, vocal folds adduct/close

Stages of swallowing

1. Oral preparation

2. Oral transit/transit

3. Pharyngeal swallow

4. Esophageal transit

Prepare food, Push bolus backward, Protect airway, Pass through esophagus

Styloglossus

 elevates/retracts tongue.

pulls tongue UP and BACK

Genioglossus

protrudes/depresses tongue

Superior longitudinal

intrinsic muscle; curls/elevates tongue tip

Hyoglossus

depresses/retracts tongue

Chewing reflex

Deep pressure on roof of mouth

Gag reflex

Touch faucial pillars/posterior pharynx

Cough reflex

Noxious stimulation of pharynx, larynx, or bronchial passageway

Sucking/rooting

Light touch to lips and cheeks

Palatal/uvular reflex

Touch uvula or fauces

Tongue base retraction

Bolus/pressure on tongue

Retch/vomit

Can be triggered by:

• Noxious smell

• Taste

• GI distress

• Vestibular dysfunction

• Distressing visual/mental stimulation

IDDSI syringe flow test

The IDDSI Flow Test is used for drinks/liquids, specifically:

• Level 0

• Level 1

• Level 2

• Level 3

The muscles that can help lower the velum include:

Palatoglossus
Palatopharyngeus

Levator veli palatini

elevates the velum

Orbicularis oris

lips

Nociceptors

detect pain

Thermal receptors

hot, warm, cold, cool

sucking

Touch lips/cheeks

Palatal

Touch uvula/fauces

gag

Touch faucial pillars/posterior pharynx

Tongue base retraction

Bolus/pressure on tongue

Cough

Noxious stimulation of pharynx/larynx/bronchial passageway

Retch/vomit

Noxious smell, taste, GI distress, etc.

oral preparation

Food enters mouth, Chewing, Saliva mixes with food, Bolus is formed, Velum DOWN, Breathing continues through nose

oral transit

Tongue pushes bolus backward, Tip of tongue contacts superior alveolar ridge, Velum still DOWN, Bolus moves toward fauces

Pharyngeal

Vocal folds close, False vocal folds close, Larynx elevates, Epiglottis inverts, Hyoid moves up and forward, Pharynx contracts, Cricopharyngeus relaxes, Bolus moves toward esophagus

Esophageal

Bolus enters esophagus, Peristalsis moves it toward LES, About 8–20 seconds

Oral transit

 < 1–1.5 sec

Pharyngeal transit

<1 sec

Esophageal

8-20 sec

And the pharyngeal swallow trigger happens when:

the bolus reaches the posterior tongue/fauces

Parotid

serous, thin, slippery, helps move bolus

Sublingual

mucoidal, thick, binds/organizes bolus

Submandibular

combination of serous + mucoidal

Parotid

CN IX glossopharyngeal

Sublingual

CN VII facial

Submandibular

CN VII facial