Swallowing, Phonation and Articulation

Question 1

What is swallowing called technically?

Answer 1

DEGLUTITION

Question 2

What is swallowing (Deglutition?)

Answer 2

Coordinated actions of structures in oral cavity &

pharynx, especially tongue & palate.

Question 3

Is swallowing voluntary or involuntary?

Answer 3

Both - voluntary while awake, involuntary while asleep

Question 4

How many times a day do we swallow on average?

When awake? When asleep?

Answer 4

500-700 or more for some people

We swallow about once a minute while awake, and
about 3 times an hour when asleep

Question 5

How many muscles does swallowing use?

Answer 5

26

Question 6

What is dysphagia?

Answer 6

Difficulty is swallowing caused by an injury or disorder

Question 7

What are the 4 phases of swallowing

Answer 7

1. Oral preparatory phase: voluntary - mastication and formation
   of bolus
2. Oral phase: (oral transit/oral propulsive phase): voluntary -
   bolus moved to posterior part of oral cavity
3. Pharyngeal phase: mainly automatic, bolus is triggered to pass
   through pharynx
4. Oesophageal phase: automatic. Peristaltic waves of smooth
   muscle transport bolus to stomach

Question 8

What happens in:

1. ORAL PREPARATORY PHASE of swallowing

Answer 8

• Preparing food for swallowing.
• Chewing/moistening food, collecting
into a “bolus,” for easy swallowing.
• Lips – closure and movement
• Tongue – coordinated movement and
pressures created
• Teeth, with mandibular movement:
chewing
• Salivary glands – to mix with food
• Larynx and pharynx are at rest during
this stage. Breathing still continues
• Anterior & posterior tongue elevated
• Soft palate still lowered, containing
the bolus in the oral cavity

Question 9

What happens in:

2. ORAL (TRANSIT/PROPULSIVE) PHASE of swallowing

Answer 9

• Tongue uses an anterior to posterior
action to move bolus back along a
central groove
• Lips are still sealed
• Bolus pushed against hard & soft
palates
• Pushed posteriorly towards the
oropharynx
• Triggers swallowing; 1-1.5 seconds
• Soft palate contains bolus in oral
cavity, not letting it fall over the base
of the tongue

Question 10

What happens in:

3. PHARYNGEAL PHASE of swallowing

Answer 10

• Triggered by sensory receptors when bolus
passes palatoglossal arches
• Lasts 1 second
• Soft palate elevates, closes off nasal
cavity
• Hyoid and larynx elevate (2-3cm) and move
anteriorly.
• Breathing stops
• Airway is protected by retraction of
tongue to pharynx
• Closure of epiglottis and vocal folds
• Pharyngeal elevation by contraction of
pharyngeal constrictor muscles.
• Upper oesophageal sphincter (UES) opens
• Bolus enters oesophagus

Question 11

What happens in:

4. OESOPHAGEAL PHASE of swallowing

Answer 11

• Bolus then enters the oesophagus
• A reflexive phase = involuntary
• Bolus moved by peristaltic
contractions of oesophagus
toward stomach.
• May last 8 seconds, depending on
bolus.
• When the bolus is in the
oesophagus, breathing resumes.

Question 12

What is the sequence to produce voice?

Answer 12

• We inhale quickly.
• Vocal folds are adducted.
• Expiration ➜ build-up of air pressure beneath closed vocal folds =
subglottal (or subglottic) pressure.
• Pressure reaches a threshold level - momentarily blows vocal folds
apart and air flows superiorly past glottis.
• Airflow speed is increased through glottis, air pressure
momentarily decreases, causing the vocal folds to be sucked back
together again (the Bernoulli effect), allowing the air pressure to
build up again, and so on.
• This repeated action (of blowing apart + sucked back together
again) creates the vibration of the vocal folds, which can occur
hundreds of times per second or more.
• Laryngeal adduction muscles - in constant contraction, with
expiration.
• To stop phonation, use laryngeal ABductor muscle to open vocal
folds.

Question 13

What is phonation?

Answer 13

Producing voice