The Neurology of Swallowing Flashcards
What is the Swallowing “Model” Assumption
There is a general assumption that we need good sensory input in order to create a motor plan and therefore the appropriate motor output suitable for the bolus.
It comes from the observation that we require different ‘types’ of swallows for different bolus sizes
How many senses are there?
8
What are the 8 senses
Introspection - feeling of hunger, fullness, hot/cold
Visual- amygdala and hippocampus stimulated - salivation
Olfactory - amygdala and hippocampus stimulated - salivation
Proprioception
Tactile - recognition in oral/ pharynx
Gustatory - Taste
Vestibular - Balance
Auditory - May affect hyper/hypo sensitive children
Which cranial nerves provide sensory information
Trigeminal Nerve (V) - Important for the position of the bolus in the mouth/ cheeks. Also important for teeth and gums sensation. Also provides sensory information from the face, cheeks, lips, hard palate and pharynx
Facial Nerve (VII)- Provides sensory information for taste sensation to the anterior 2/3 of the tongue. It also provides sensory information to the face/ oral cavity/ soft palate. It also stimulates the salivary glands
Glossopharyngeal Nerve (IX)- Provides sensory information for taste sensation to the posterior 1/3 of the tongue. It stimulates the Parotid gland (saliva) and the Gag reflex
Vagus Nerve X- Provides sensory information around the sensation of food residue in the larynx, pharynx and oesophagus
Where is sensory information processed in the Brain
Sensory information is processed by the Brain Cortex (there are many different cortex’s in the brain: auditory, vestibular, somatosensory, visual, gustatory, olfactory and auditory) this is then relayed to the brainstem. This is thought to contain the main swallowing centres.
The Upper Motor neurons carry down the signal to the brain stem for processing
How is the sensory information converted into motor output in swallowing
The Pons and the Medulla (located in the brain steam) are thought to be the main swallowing centres. They control the sequential muscle activity which is needed to swallow. It controls the strength of the muscles and also the order in which they are triggered to contract/ relax to swallow.
