This document discusses the process of deglutition (swallowing). It begins with an introduction describing that swallowing involves coordinated activity of the oral cavity, pharynx, larynx, and esophagus muscles. It is partly under voluntary and partly under reflexive control. The document then covers the components, phases (oral, pharyngeal, esophageal), muscles involved, theories of swallowing, and neural control of deglutition. Key points include that swallowing has oral preparatory and oral phases under voluntary control and a pharyngeal phase that is reflexive, propelling the bolus into the esophagus for involuntary transport.

3. INTRODUCTION
Deglutition involves co-ordinated activity of muscles of oral cavity,
pharynx, larynx & esophagus
The whole process is partly under voluntary control & partly reflexive
in nature
Voluntary control of deglutition involves control of jaw, tongue, degree
of constriction & length of pharynx
3

4. DEFINITION
Complex series of voluntary and involuntary neuromuscular
contractions proceeding from the mouth to the stomach & is
commonly divided into oropharyngeal & esophageal stages.

5. COMPONENTS OF DEGLUTITION
Deglution has 3 components
Passage of bolus from oral cavity to stomach
Protection of airway
Inhibition of air entry into the stomach
5

6. THEORIES
OF
DEGLUTITION

7. THEORYOF CONSTANT PROPORTION
Describes passage of bolus through upper GIT in three phases
 ORAL PHASE : voluntary control
 PHARYNGEAL PHASE : pharynx is activated to propel the bolus
 ESOPHAGEAL PHASE : by esophageal contraction

8. THEORYOF ORALEXPULSION
This theory states that “the oral expulsion arising from contraction of
tongue & Mylohyoid throws bolus into the stomach”

9. THEORYOF NEGATIVE PRESSURE
According to this theory :
“the tongue is brought forward to create a negative pressure
which is accentuated by the descent of the larynx & therefore the food
is sucked into the esophagus.”

10. THEORYOF INTEGRALFUNCTION
This theory is based on myometric & electromyographic studies &
considers the act of swallowing as a total dynamic process.
• It is the most accepted theory.

11. DEGLUTITION - PHASES
11
ORAL
PHARYNGEAL
ESOPHAGEAL

12. ORAL PHASE
Food is prepared for swallowing
Tongue plays a vital role
Divided into Oral preparatory phase & Oral phase proper
Under voluntary control
12

13. MASTICATION OR CHEWING
CHEWING is a program of mandibular movements patterned in a
sequence of distinctive recurring cycles.
Co-ordination of chewing process matures at about 4 years of age after
the deciduous dentition has fully erupted

14. MASTICATORYCYCLE : 1st MOVEMENT
THE OPENING MOVEMENT :
• Mandible is lowered mainly by gravity
• Contraction of anterior belly of Digastric
• Jaw is prevented from dropping by gradual relaxation of Temporalis
& Masseter
• Usually deviates to the non–working side

15. THE CLOSING MOVEMENT
• Mandible is rapidly raised until trapped food is felt
• It swings swiftly & rather widely to the working side
• Contraction of Masseter & medial pterygoid muscles
• Teeth are brought into initial contact with the food
MASTICATORY CYCLE : 2nd MOVEMENT

16. THE POWER STROKE :
• The food is compressed, punctured, crushed & sheared
• The teeth meet in lateral occlusion & then slide into centric
relation
• There is further contraction of Masseter & Temporalis

17. MUSCLES
ASSOCIATED WITH
SWALLOWING

18. The muscles that play an important role in the process of swallowing
includes :
• MUSCLES OF THE TONGUE
• THE MUSCLES OF THE SOFT PALATE : during swallowing it
separates nasopharynx from oropharynx.
• THE MUSCLES OF PHARYNX : which helps in passage of bolus
to the stomach.

19. MUSCLES OF THE TONGUE
Retracts & elevates the posterior third of the tongue.
Narrows oropharyngeal isthmus.
Makes dorsum convex
Protrude the tongue.
shortens the tongue & makes the dorsum concave.
broadens & flattens the tongue.
.
narrows & elongates the tongue
shortens the tongue & makes the dorsum convex

20. APPLIEDANATOMY
• Injury to hypoglossal nerve produces paralysis of the muscles of the
tongue on the side of lesion
• In cases of acute glossitis tongue fills the oral cavity & protrudes out
of it causing difficulty in mastication
• In unconscious patients tongue may fall back & obstruct the air
passage. This can be prevented by lying the patient in semi reclined
position with head down.

21. SOFT PALATE
Movable, muscular fold suspended from posterior border of hard palate.
It is composed of :
• Mucous membrane
• Palatine aponeurosis
(forms fibrous basis)
• Muscles

22. MUSCLES OF THE SOFT PALATE

23. ORALPREPARATORYPHASE
Involves breaking down of food in the oral cavity
Food is chewed & mixed with saliva making it into a bolus which can
be swallowed
The elevators of lower jaw play an important role in bolus preparation
23

24. Tongue –helps in bolus formation by the action of its intrinsic muscles
which alters its shape. Its extrinsic muscles changes its position within
the oral cavity thereby helping in chewing the food by dental occlusion
Occlusal action of the lips - seal & prevent the bolus from dribbling out
of the oral cavity
Buccinator muscle – Push the bolus out of the vestibule into the oral
cavity proper

25. ORAL PREPARATORY PHASE
(CONTD)
SALIVARY GLANDS:
Salivary glands -ducts – saliva- mouth
Saliva contains:
 Mucin- holds food together.
 Salivary amylase- starts digesting
carbohydrates.
 Bicarbonates-maintain PH level of
saliva & protect teeth.
 Lysozymes-inhibits bacterial growth.
25

26. BOLUS FORMATION
Most important function of preparatory
phase
This involves repeated transfer of food
from oral cavity to oropharyngeal
surface of tongue
Bolus accumulates on the
oropharyngeal surface of tongue due to
repeated cycles of upward & downward
movement of the tongue
26

27. ORAL PHASE PROPER
The bolus is moved towards the back of the tongue
The contraction of soft palate prevents nasal regurgitation
The soft palate also prevents premature
movement of bolus into the oropharynx
Once the bolus is of suitable consistency,the transit
from mouth to oropharynx just takes a couple of seconds
Tongue & the elevation of the mandible plays a vital role
during this Phase.Intrinsic muscles of tongue contracts & reduces its size,
while genioglossus muscle elevates the tongue towards the palate.
When the mandible is elevated the suprahyoid muscles raises the hyoid
bone 27

28. PHARYNX
• Wide muscular tube situated behind nose, mouth & larynx.
• Length = 12 cm.
• Width = 3.5 cm & narrows as it goes down.
Divided into

29. MUSCLES OF PHARYNX
• STYLOPHARYNGEUS
elevates larynx during swallowing
• SALPINGOPHARYNGEUS
elevates larynx
• PALATOPHARYNGEUS
CONSTRICTORS
• SUPERIOR CONSTRICTOR
Aids soft palate in closing the nasopharynx,
propels bolus downwards
• MIDDLE CONSTRICTOR
propels bolus downwards
• INFERIOR CONSTRICTOR
propels bolus downwards & forms sphincter at lower end
(cricopharyngeus)

30. PHARYNGEAL PHASE
(PUMPINGACTIONOF TONGUE &HYPOPHARYNGEAL SUCTION)
Reflexive & involuntary in nature
It just takes a second for the bolus to traverse the pharynx & reach the
cricopharyngeal area
Contraction of diaphragm is inhibited making simultaneous breathing &
swallowing impossible
During this stage ,bolus from pharynx can enter into 4 paths:
1. Back to mouth
2. Upwards into nasopharynx
3. forwards into larynx
4. Downwards into esophagus 30

31. Back into mouth
Position of tongue
High intra oral pressure developed by the movement of tongue
Upwards into nasopharynx
Prevented by elevation of soft palate along with its extension
uvula
Forwards into larynx
Approximation of vocal cord
Forward & upward movement of laryx
Backward movement of epiglottis to seal the opening of the larynx
Temporary arrest of breathing

32. FUNCTIONSOFTRIGGERPOINTSINOROPHARYNX
Stimulation of trigger points - starts off at
the pharyngeal reflexive stage of
swallowing
Trigger points -present at the faucial
arches & mucosa of the posterior
pharyngeal wall
Trigger points are innervated by IXth CN
32

33. Stimulation of these trigger points causes dilatation of pharynx due to
relaxation of the constrictors, &
elevation of pharynx & larynx due to contraction of longitudinal
muscles
The pharynx constricts behind the bolus thereby propelling it
Contraction of the inferior constrictor moves the bolus towards the
oesophagus.

34. ESOPHAGEAL STAGE
This is purely reflexive &
involuntary
This phase begins by relaxing
the cricopharyngeal sphincter
The time taken for esophageal
transit is 10-15 seconds
Primary / secondary / tertiary
peristaltic waves play active
roles in this phase
34

35. Means a wave of contraction followed by a wave of relaxation of
muscle fibres of GIT ,which travel in aboral directon(away from mouth)
With this ,contents are propelled down along GIT

36. Weaker Waves
Controlled by deglutition centre
Starts when bolus reaches upper part of esophagus
Propels food towards the stomach
Initially negative pressure is created in the upper part of esophagus-due
to the stretching of closed esophagus by elevation of pharynx
But immediately pressure becomes positive

37. Arise in esophagus locally due to the distention of upper esophagus
by the bolus
Produces a positive pressure
If primary peristaltic contractions are unable to propel the bolus into
the stomach,the secondary peristaltic contractions appear & push the
bolus into stomach
Eg :cheese
Controlled locally by myenteric plexus by releasing Acetyl Choline

38. Irregular, non propulsive contractions involving long segments which
occur during emotional stress

39. Distal 2-5cm of esophagus acts like a sphincter.
It is called lower esophageal sphincter
When bolus enters this part , the sphincter relaxes , so that the content
enter the stomach.
Later, the sphincter contracts
Relaxation & contraction of sphincter occurs in sequence with the
arrival of peristaltic contractions of esophagus

40. Beginning of swallowing
Initially -Voluntary act……….Later-involuntary act
Occurs through reflex action called deglutition reflex

41. NEURAL CONTROL

42. Initiated when food comes in contact with certain trigger areas like
fauces, mucosa of posterior pharyngeal wall
Via Glossopharyngeal Nerve to brainstem

43. Fourth ventricle in the medulla oblongate of brain
Travel through glossopharyngeal & vagus nerves(parasympathetic
motor fibers) & reach soft palate ,pharynx & esopahgus
Glossopharngeal nerve is concerned with pharyngeal stage of
swallowing .
Vagus nerve is concerned with esophageal stage

44. Reflex causes upward movement of soft
palate to close nasopharynx & upward
movement of larynx to close respiratory
passage so that bolus enters the
esophagus

45. PHASE OF RESPIRATION & SWALLOWING
Swallowing occurs during expiratory phase of respiration
This helps in clearing food material left in the vestibule. Thus it
should be considered to be a protective phenomenon
The rhythm of respiration is reset after a successful swallow
45

46. APPLIED PHYSIOLOGY
DYSPHAGIA
ODYNOPHAGIA
GLOBUS HYSTERICUS
PHAGOPHAGIA
PRESBYDYSPHAGIA
VOMITING
DEGLUTITION APNEA
ASPIRATION
CRICOPHARYNGEAL
DYSFUNCTION
CHOKING
ANTIPERISTALSIS
GAG REFLEX

47. Difficulty in swallowing…….Coexist with heart burn & vomiting
Pathophysiology Of Dysphagia
Lack of coordination or strength of muscles Or Mechanical obstruction
If contractions fail to develop progress ,bolus distends the oesophageal
lumen & causes discomfort
Low amplitude of 1O& 2O peristaltic activity is insufficient to clear
oesophagus as in elderly individuals
Mechanical narrowing of oesophageal lumen obstructs passage of
bolus despite adequate contractions
Abnormal sensory perception in oesophagus may cause sensation of
dysphagia even after bolus is cleared

49. Is highly integrated & complex reflex invloving both autonomic &
somatic neural pathways
Synchronous contraction of diaphragm ,intercoastal muscles &
abdominal muscles raises intra abdominal pressure & combined with
LES –forcible ejection of gastric contents
Imp to distinguish between vomiting & regurgitation
Associated symptoms: abdominal pain,fever,diarrhoea

51. Arrest of breathing during deglutition.
Occurs reflexly during pharngeal stage.
When bolus is pushed into esophagus from pharynx during pharyngeal
stage,there is possibility for the bolus to enter the respiratory passage
through trachea...........which may cause choking
To prevent this,there is apnea along with approximation of vocal cords ,
forward & upward movement of larynx &
backward movement of epiglottis to close the larynx

52. Defined as the inhalation of oropharyngeal or gastric contents into the
larynx & lower respiratory tract
Aspiration Pneumonitis (Mendelson’s Syndrome) chemical injury
caused by the inhalation of sterile gastric contents
Aspiration Pneumonia is an infectious process caused by the inhalation
of oropharyngeal secretions that are colonized by pathogenic bacteria.
Risk Factors For Oropharyngeal Aspiration
Elderly, neurologic dysphagia, GERD
Poor oral hygiene-colonization by respiratory tract pathogens
Silent aspiration is common in stroke.
Management :
Upper respiratory suction,Antbiotics,ET intubation for airway

53. Failure of the tonically contracted upper esophageal sphincter to relax and
open when one swallows.
Symptoms
pills or solid food begin to lodge at the level of the lower part of the
larynx.
Treatment
Resolved through surgical procedure Cricopharyngeal Myotomy

54. Mechanical obstruction of the flow of air from the environment into the
lungs that prevents breathing
Prolonged choking-asphyxa-anoxia-fatal
Causes:
Foreign body,respiratory disease,compression of laryngopharynx
Signs & symptoms
Person cannot speak or cry, Violent cough
Difficult in breathing ,produce wheezing sounds, Clutches throat
If respiration not restored ,then cyanosis
Treatment
BLS & ALS
Heimlich maneuver

55. Wave of contraction in digestive tract that moves toward the oral end
of tract -regurgitation

56. Characteristic changes in the swallowing mechanism of otherwise
healthy older adults.
AGE ASSOCIATED CHANGES
Demonstrate delay in onset of specific pharyngeal events
Swallowing is slow
Larger duration
Upper Esophageal Sphincter
opening is delayed
Chance of Aspiration-more

57. • Painful swallowing
• Sensation of a lump lodged in throat
• Fear of swallowing as in rabies, tetanus, pharyngeal paralysis due to
fear of aspiration

58. GAG REFLEX
Stimulation of sensitive areas of pharynx, soft palate, uvula, tongue
Stimulation of Trigeminal & Glossopharyngeal & Vagus nerves
Uncoordinated & spasmodic movements of swallowing muscles
Gagging
Causes
chemical irritants, toxic materials, specific drugs, severe pain, mild
stimulation of pharynx etc.
Treatment
• Removal of factors
• Local anesthetic may be used while working
• Drugs like atropine along with a sedative may be prescribed
• Acupressure

59. Plain X-Ray
Barium swallow
CT & MRI
Videofluroscopy
STUDY OF SWALLOWING

60. PLAIN X-RAY
X-RAY SOFT TISSUE NECK
Lateral view &AP view
LATERAL VIEW(taken in full inspiration with neck extention)
Examine patency of airway
Examine soft tissues of neck
Examine the cervical vertebra
Foreign body
AP VIEW
For glottic & subglottic areas
CHEST X-RAY
PA View
Lateral View

61. Prevertebral abscess

62. BARIUM SWALLOW
PROCEDURE
Patient is given liquid barium(Barium suphate)to swallow while bolus is
followed fluroscopically.
Look for-Filling defect , Obliterative lesions , Extrinsic compression
ADVANTAGES:
 Inert,Suspendable in water
 Very minimal absorption in GIT
DISADVANTAGES:
Outside the lumen of GIT acts as foreign body
Contrast leak in mediastinum leads to inflammatory reaction

63. AchalasiaCardia
Diffuse Esophageal
Spasm
Esophageal
Carcinoma

64. AIR CONTRAST OESOPHAGRAM
Performed like barium swallow but with addition of effervescent
granules to barium
Advantages:
 Better anatomical details especially edge contrast
Disadvantages:
 Irradiation
 Documented on plain film
Normal
Fungal
Plagues

65. VIDEOFLUOROSCOPY
Definition
Dynamic fluoroscopic imaging procedure that enables visualization of
rapid & integrated movements involved in all phases of deglutition
Equipment
 X-Ray screening facility
 Digital/video recorder with microphone & timer

66. CT & MRI
CT used to stage the disease in malignant
MRI used to detect intracranial lesions and vascular abnormalities
DISADVANTAGES
Expensive
Patient has to be in supine which does not reflect stages of swallowing

67. SPECIALTECHNIQUES
Manometry
Manofluroscopy
Direct pharyngoscopy
Endoscopy
Bolus scintigraphy
24 hr oesophageal ph monitoring

68. MANOMETRY
Definition
Technique used to measure intraluminal pressure & coordination of
pressures in 3 regions
 Lower esophageal sphinchter(LES)
 Oesophageal body
 Upper esophageal sphinchter(UES)
To assess oesophageal peristalsis & oesophageal motor
dysfunction

69. MANOFLUROSCOPY
Similar to videofluroscopy & manometry
Advantages
Combines pressure & bolus information simultaneously
Disadvantages
Not widely used
Costly

70. DIRECT PHARYNGOSCOPY
Done under general anaesthesia
Used to visualize the pharynx & upper oesophagus
To take biopsy and staging tumors of pharynx & upper
oesophagus
To examine postcricoid area

71. Endoscopy /
Fibreoptic Endoscopic Evaluation Of Swallowing
(FEES)
Done in acute stages of dysphagia,Persistent dysphagia
Assesment of pharyngeal and laryngeal anatomy and physiology with
normal food and drink
Procedure
Patient sits upright,nose examined for any septal deviation
Decongestants & lubrication of nasal passages along with topical
anaesthesia
Scope passed between inferior turbinate & floor of nose
Examine nasopharynx for nasal reflux, oropharynx and hypopharynx

72. BOLUS SCINTIGRAPHY
Short lived isoptope mixed with single swallow bolus
Gamma camera registers the radiation
Bolus transit & aspiration assessed
Advantages
 Aspiration assessed
Disadvantages
 Oropharyngeal anatomy not assessed
 Cannot perform multiple swallows
 Technical expertise needed

73. ULTRASOUND
Submental transducers used to image
 Structures
 Mobility of bolus transit
 Vallecular status
Advantages
 Avoids irradiation
 Normal food used(no barium)
Disadvantages
 Cannot be used to visualize larynx & pharynx due to skeletal
interference
 Not effective for esophageal phase

74. OESOPHAGEAL PH MONITORING
24hrs ambulatory Ph monitoring –reliable for GERD
Procedure
 Proximal probe placed below UES
 Distal probe placed 5cm above LES(position detected by
manometry)
 Reflux measured along entire length of esophagus
Disadvantage
 Invasive
 Provokes relux