stages of swallowing , approach in a pt with swallowing difficulty

1. Physiology of
swallowing
Dr Safika Zaman
Dept of ENT & HNS

2. Introduction
• Coordinated activity of muscles –
 Oral cavity
Pharynx and Larynx
 Oesophagus
• Motor activity – Both reflex and voluntary
control.

3. Structures involved
• Muscles controlling - position of the lips
• Elevation and depression of the jaw
• Position and degree of contraction of the tongue
• Degree of constriction and length of the pharynx
• Closure of the laryngeal inlet
• Cricopharyngeal sphincter
• Muscles of the oesophagus and oesophageal sphincter

4. MUSCLES OF MASTICATION
Supra-mandibular
muscles(Jaw elevators) -
attached between the
mandible and the skull
Comprise the muscles
of mastication,
temporalis, masseter
and the medial and
lateral pterygoid
muscles.

5. Inframandiular Muscles
The inframandibular
muscles are composed of
the suprahyoid and
infrahyoid muscles of the
neck.
 Action: in raising or
lowering the hyoid bone.

6. Tongue Muscles
• Intrinsic muscles: responsible for
changing the shape of the tongue.
• Extrinsic muscles: responsible for
altering the position of the tongue
in the mouth.

7. Tongue Muscles
• The actions of these two groups of
tongue muscles are not entirely
independent since changes in
tongue shape will result in changes
in tongue position and vice versa.

8. Pharynx

11. Cricopharyngeal sphincter
• Cricopharyngeal sphincter:
at the point where the
laryngopharynx joins the
oesophagus.
• Contains a high proportion
of elastic fibres to aid its
sphincteric function.

12. The larynx
• The larynx is suspended from
the hyoid bone by the thyrohyoid
membrane and thyrohyoid
muscle.
• When the suprahyoid and
infrahyoid muscles move the
hyoid bone, they also alter the
height of the larynx.
• Adductors and abductors of
vocal fold – during digludition

13. THE SEQUENCE OF EVENTS IN NORMAL SWALLOW

14. Pre- requisite for oral transit- mandibular elevation
• Adequate lingual pressure generation
• Assist the suprahyoid muscles in
raising the hyoid bone.
• Elevated, flattened tongue pushes the
bolus against the hard palate, and the
sides of the tongue seal against the
maxillary alveolar processes.

15. Oral phase for liquids
• Soft palate is kept lowered by the
contraction of the palatoglossus and
palatopharyngeus
• Posterior tongue is simultaneously
elevated
• Airways remain open during this
phase
• Bolus is transported through the
palatoglossal and palatopharyngeal
arches into the oropharynx

16. Oral phase for solids
Food is mixed with saliva and reduced to smaller particles
Bolus converted to a suitable consistency to be swallowed
Transferred to the oropharynx, valleculae and posterior part of the tongue
Retrolingual loading - retained for a few seconds in base of the tongue
prior to swallowing.
Oral preparatory, oral transport and pharyngeal phases overlap when
solid food is being swallowed.

17. Pharyngeal phase
• Pharyngeal phase : bolus leaving the oral cavity to
enter the pharynx until it passes into the oesophagus.
• Involuntary phase: reflex behaviour.
• Diaphragmatic contraction is inhibited making
simultaneous breathing and swallowing impossible
under normal circumstances.
• Palatopharyngeal fibres to form a variable, ridge-like
structure (Passavant’s ridge) against which the soft
palate is elevated

18. Pharyngeal phase
• Bolus touches key trigger points
• Patterned response is initiated in which the constrictors relax to dilate the
pharynx
• Pharynx and larynx are raised by the longitudinal muscles.
• Solid boluses are propelled over the epiglottis by the action of the
constrictors contracting in sequence.
• Larynx is then closed by contraction of the muscles of the laryngeal inlet

19. Laryngeal events
• Laryngeal elevation - Suprahyoid muscles move the hyoid bone anteriorly,
contributing to pharyngeal dilation.
• Raising the larynx narrows the laryngeal inlet.
• Moves the larynx towards pharyngeal surface of the epiglottis as the
laryngeal cartilages move anteriorly, tucking under the bulge of the posterior
tongue, i.e. out of the path of the bolus.

20. Pressure change
• A hypopharyngeal suction pump: by the elevation and anterior movement
of the hyoid and larynx, which creates a negative pressure in the
laryngopharynx, drawing the bolus towards the oesophagus, aided by a
more negative pressure inside the oesophagus.
• The pharyngeal constrictors generate a positive pressure wave behind the
bolus. Their sequential contraction may facilitate clearance of any
pharyngeal wall or piriform sinus residue.

21. Esophageal phase
• The oesophageal phase : Relaxation of the
cricopharyngeal sphincter has allowed the
bolus to enter the oesophagus.
• This is a true peristalsis in which a
relaxation in front of the bolus and a
constriction behind the bolus move it
towards the stomach.

22. Neural control of swallowing
• Multidimensional in nature - recruiting at all levels of the nervous system.
• Brainstem swallowing centre : contains the central pattern generator, is at
the core of the system and represents the first level of control.
• Second level of swallowing control are the subcortical structures, such as
the basal ganglia, hypothalamus, amygdala, and tegmental area of the
midbrain.
• Third level of swallowing control: Suprabulbar cortical swallowing centre.

23. Neural Control of Feedingand SwallowingSatish Mistry, PhD*,
Shaheen Hamdy, PhD, FRCPUniversity of Manchester, School of Translational Medicine, Gastrointestinal Sciences,
Faculty of Medical and Human Sciences, Clinical Sciences Building, Salford Royal NHSFoundation Trust,

25. Trigeminal Nerve
• Sensory: conveys most sensory modalities
(touch, temperature, pressure, and pain),
except taste, from the anterior thirds of the
tongue, face, mouth, and mandible.
• Motor: innervates muscles of mastication.

26. Facial Nerve
• Special sensory: conveys taste from
the anterior two thirds of the tongue
and soft palate by way of greater
petrosal and chorda tympani, which
also stimulates saliva secretion.
• Mixed-motor: supplies muscles of
facial expression, particularly the lips,
which prevent spillage during the oral
phase of swallowing.

27. Glossopharyngeal Nerve
• General sensory: mediates all sensation from
posterior one third of tongue, oropharyngeal
mucosal membranes, palatine tonsils, and
faucial pillars.
• Special sensory: conveys taste from posterior
one third of tongue.
• Motor: in conjunction with the vagus nerve
innervates the stylopharyngeus, which
elevates and pulls anterior the larynx to aid
cricopharyngeal relaxation.
• Secretomotor: stimulates saliva secretion
from parotid gland.

28. Vagus Nerve
• Motor: responsible for raising the velum as it
innervates the glossopalatine and the levator
veli palatine muscles.
• Pharyngeal branch innervates the pharyngeal
constrictors and intrinsic laryngeal
musculature.
• It is also responsible for vocal fold adduction
during swallowing and crico-pharyngeal
relaxation.
• Muscles involved in the esophageal stage of
swallowing and those that control respiration
are also innervated by the vagus.

29. Vagus Nerve
• Sensory: superior and recurrent laryngeal nerves carry information from
the velum and the posterior and inferior portions of pharynx, and mediate
sensation in the larynx.
• The superior laryngeal nerve has been shown to potentiate the swallow
response when combined with cortical stimulation.
• Two branches of SLN : the internal, which supplies the mucous
membrane of the larynx above the vocal cords, and the external, which
supplies the inferior pharyngeal constrictor and the cricothyroid muscles.

30. Hypoglossal nerve
• Motor: innervates all intrinsic and
extrinsic tongue muscles (except
palatoglossus innervated by cranial
nerve XI).

31. Infant Swallowing
• New born feeding is primarily reflexive.
• Dependent on a rooting reflex to latch on to a nipple.
• Suckling requires the generation of intraoral pressure
via lip seal around the source and the posterior
tongue moving towards the soft palate.
• On average, infants generate two to seven tongue
pumps per swallow.
• Jaw movement creates an external pressure on the
nipple or teat, encouraging liquid flow into the oral
cavity.
• Swallow apnoea is mainly attributed to the larynx
tucking under the tongue base and the arytenoids
tilting forwards.

32. Presbyphagia
Presbyphagia is defined as normal age-related changes in swallowing in
healthy adults.
Weaker oral phase movements, including reduced tongue strength.
The pharyngeal phase is often longer in duration, with prolonged
hyolaryngeal excursion.
Breathing and swallowing coordination may also decrease with age, with
over all longer periods of apnoea

33. Swallow Apnea
• Ventilation has to be suspended during
pharyngeal transit of the bolus.
• This is known as the period of swallow
apnoea and is typically less than
1 second in length.
• Corresponding to the duration of the
reflex part of the swallow in its
pharyngeal phase

34. Dysphagia
• Dysphagia is a term used to describe difficulty with swallowing solids,
liquids or both. It implies impairment of one or more of the phases of
swallowing.
• Dysphagia usually arises as a complication of another health condition. It
can be divided into oropharyngeal (high) dysphagia and oesophageal
(low) dysphagia.
• Dysphagia is common, with epidemiologic studies suggesting that as
many as 22% of the population over the age of 50 are affected

35. Causes of dysphagia
Congenital Cleft lip and palate
Cerebral palsy
Vascular rings Atresis
Clefts and fistula
Congenital vocal cord palsy
Infective Acute and chronic infections of pharynx/larynx
Neck space infections
Inflammatory Gastro-oesophageal reflux disease
Laryngopharyngeal reflux
Patterson–Brown–Kelly syndrome
Eosinophilic oesophagitis
Autoimmune Scleroderma
Systemic lupus erythematosus
Sjögren’s syndrome
Pemphigus, epidermolysis bullosa
Dermatomyositis

36. Traumatic Foreign body
Food bolus obstruction
Caustic burns
Head and neck trauma
Neoplastic Benign tumours
Malignant tumours
Motility disorders Achalasia cardia
Oesophageal spasm
Presbyoesophagus
Neurological Cerebrovascular accident
Parkinson’s disease
Multiple sclerosis
Motor neurone disease
Myasthenia gravis
Vocal cord palsy
Miscellaneous Post-treatment dysphagia
Pharmacological Globus pharyngeus
Pharyngeal pouch

37. Assesment of Dysphagia
• History - include the onset, duration, progression
and severity of the symptoms, as well as the
types of food that give problems
• Regurgitation
• Odynophagia
• Hoarseness
• Referred otalgia
• Associated neurological symptoms

39. Feeding Problems and Long-Term Outcomes in Preterm Infants—A Systematic Approach to Evaluation and Management
by Ranjith Kamity 1,*ORCID,Prasanna K. Kapavarapu 2 andAmit Chandel 3

40. Investigations
• Videofluoroscopy
• Endoscopy
• Radiography
• Ultrasound
• Electromyography (EMG) recording
• Functional MRI,

41. Thank You