Transcript SALC07 Biological Sciences Head & Neck 4: Normal Swallow

SALC07 Biological Sciences
Head & Neck 4:
The Typical Adult Swallow
Flora Hall MCRSLT/HPC
[email protected]
Review of oral &
pharyngeal anatomy
Cavities of the oropharynx:
 Oral
 Nasal
 Oropharynx, naso- and laryngopharynx
 Pharynx
The oral cavity
Extends from oral
opening (lips) to
pillars of fauces at
back
Teeth and alveolar
ridge or maxillae
make up lateral
margins
Soft palate
•Uvula
•Velum
Pillars of fauces
•Anterior
•Posterior
Also known as
glossopharyngeal
arch
Muscles of the velum
Muscle
Function
Levator veli palatine
Elevator
*also movement of Eustachian
tube
Musculus uvulae
Elevator/bunching
Tensor veli palatine
Tenses and shortens
Palatoglossus
Depressor
Palatopharyngeus
Depressor
The pharynx
Divided into areas:
1. Oropharynx
2. Nasopharynx
3. Laryngopharynx
Pharyngeal muscles
 Superior
pharyngeal
constrictor
 Middle pharyngeal
constrictor
 Inferior pharyngeal
constrictors
Muscle
function
Innervation
Superior pharyngeal
constrictor
Velopharyngeal closure
Reduces diameter
CN XI & X
Middle pharyngeal
constrictor
Reduces diameter
CN XI & X
Inferior pharyngeal
constrictor
Reduces diameter:
Two parts:
CN XI & X
1. Cricopharyngeal
muscle
*arises from cricoid
Muscular orifice of oesophagus
Pharyngeal musculature
2. Thyropharyngeal
muscle
*arises from thyroid
Salpingopharyngeus
Elevates lateral pharyngeal wall
CN XI & X
Stylopharyngeus
Elevates pharynx
CN IX
Intrinsic tongue muscles
The epiglottis
 Leaf-shaped
cartilage
 Attached to root
of tongue and hyoid
Pharyngeal spaces and
places
 Valleculae
 Laryngeal
vestibule
 Pyriform sinuses
 Upper Oesophageal Sphincter
Anatomical differences
infants/adults
The infant pharynx
 Pharynx
generally curved from
nasopharynx to hypopharynx
 With growth the gentle curve gradually
changes to become closer to 90’ angle
seen in adults
Nasal breathing
 Small
oral cavity
 Close proximity of tongue, soft palate and
pharynx with the larynx appears to
facilitate nasal breathing
The typical
adult swallow
Swallowing
 Eating
and Drinking
 Feeding
 Swallowing
Deglutition: “ a complex process involving
neuromuscular control and coordination,
sensory perception, integration of the
autonomic and somatic nervous systems
and respiratory function” (RCSLT 2006)
Label the following
Nasal cavity
Teeth
Lips
Pharynx
Epiglottis
Larynx
Vocal Folds
Soft Palate
Tongue
Trachea
Oesophagus
Lungs
Stomach
Pharynx
http://www.youtube.com/watch?v=pNcV6
yAfq-g
Swallowing
Commonly divided into 4 stages:
Pre-oral stage
Oral stage (Oral preparation and oral
transit)
Pharyngeal stage
Oesophageal stage
Pre-Oral
 Anticipation
 Hunger
 Likes/Dislikes
 Mood
 Cognitive
status
 Physical status
Oral phase:
2 Parts;
1.Oral preparatory

2.

To organise food/liquid in the mouth
into a coherent bolus ready for
swallowing
Oral/Oral Transit
To propel the bolus to the back of
the mouth and trigger the
pharyngeal stage of swallowing
Oral Preparatory
 Begins
when food/liquid enters mouth at
level of lips
 Nasal airway dependent-oral closure
required
 Voluntary control
 Time-dependent on range of factors
 Ends when bolus is formed and held
ready for transit
Oral Stage: Prep
Oral Prep
continued
 Lips
& jaw close, increased buccal tone
 Range of complex and integrated tongue
movements to form bolus


Liquid bolus cupped
Solid bolus-’tippers’ & ‘dippers’
 Larynx
& pharynx at rest, airway open
 Chewing; as required. Food mixed with
saliva
 If not chewing, velum pulled anteriorally
to rest on base of tongue-prevents
spillage into pharynx & allows for variation
in intra-oral pressure
Chewing skills
 Requires
lateral, rotary and grinding
movements of tongue and jaw
 Lateral and rotary tongue>jaw
 Intermittent lip closure-Complete lip seal
 Grinding movements
Oral Stage: Transit



Intact labial seal
Anterior to posterior tongue movement,
begins ‘stripping’ action
Soft palate elevates and closes nasal
airway
Oral stage: Transit
Pharyngeal stage
Pharyngeal Stage
Oesophageal Stage
 Cricopharyngeal
sphincter relaxes and is
pulled open
 Bolus passes into oesophagus
 CP sphincter closes
 Structures return to resting position
 Lower eosophageal sphincter relaxes
Oesophageal stage
Breathing and swallowing
 Breath
is held during the swallow
 This is called APNOEA
When something goes wrong:
 Airway penetration
 Aspiration
 Silent Aspiration
 Choking
Breathing and swallowing
•
Cough response:
–
–
Needs intact sensory input from superior
laryngeal nerve (X) and effective glottic
closure
Voluntary cough may be present, but if no
sensation in laryngeal vestibule, aspiration
may still occur
The typical swallow, anatomy
again. Why is it like that?
Variations in normal
swallowing
Age Related Changes to
the Swallow
Any metabolic, biochemical and
physiological processes change with
increasing age.
Notably:
 Oral/pharyngeal motor function
 Dentition
 Hunger
 Vision
 Salivation
 Taste
Neural Regulation of
Swallowing
Neural control of swallowing
Cortex
Peri
Nucleus tractus
solitarius
Medulla
Peripheral afferent inputs
(CN’s)
Nucleus
ambiguous
Motor response (CN’s)
Cranial Nerves
–
CN V -- Trigeminal
•
•
–
CN VII -- Facial
•
•
–
contains both sensory and motor fibers that
innervate the face
important in chewing
contains both sensory and motor fibers
important for sensation of oropharynx & taste
to anterior 2/3 of tongue
CN IX -- Glossopharyngeal
•
•
contains both sensory and motor fibers
important for taste to posterior tongue,
sensory and motor functions of the pharynx
Cranial Nerves

CN X -- Vagus
 contains
both sensory and motor fibers
 important for taste to oropharynx, and
sensation and motor function to larynx and
laryngopharynx.
 important for airway protection

CN XII -- Hypoglossal
 contains
motor fibers that primarily innervate
the tongue
Is that all there is to it?