Biting Chewing and Swallowing Flashcards
3 subdivisions of the pharynx
Nasopharynx, Oropharynx, Laryngopharynx
2 types of muscle in the pharyngeal wall
3 Constrictor muscles - superior middle and inferior
2 Longitudinal muscles
Constrictor muscle contraction causes
Innervation of the constrictor muscles
Causes narrowing of the pharyngeal cavity - contract sequentially to move the bolus of food down the oesophagus
Nerve supply: pharyngeal branch of the vague nerve
Contraction of the longitudinal muscles causes
elevation of the pharyngeal wall up and over the bolus of food in swallowing
Muscles of the tongue are divided into
Intrinsic and extrinsic muscles
Tongue forms part of the ….. in ….
part of the floor in the oral cavity
part of anterior wall of the oropharynx
Innervation of the tongue
All are innervated by the hypoglossal nerve except palatoglossus - innervated by the vagus nerve
Intrinsic muscles originate and insert….
Involved in
Within the substance of the tongue
Involved in altering the shape of the tongue
Name the extrinsic muscles
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
Actions: genioglossus
Protrude and depresses tongue
Actions: Hyoglossus
Depresses tongue
Actions: Styloglossus
Elevates and retracts tongue
Actions: Palatoglossus
Depresses palate and elevates back of the tongue
Anterior 2/3 of tongue innervation: sensation and taste
sensation: Mandibular division of the trigeminal
Taste: Facial
Posterior 1/3 of tongue innervation: sensation and taste
Sensation and taste: Glossopharyngeal
Swallowing steps
1) Lift and retract the tongue (styloglossus and intrinsic muscles
2) Move bolus into the oropharynx (palatoglossus)
3) Close off nasopharynx by raising the soft palate
4) Raise larynx and close off using the epiglottis
5) Peristaltic wave of constrictor muscles
6) Relax cricopharynxgeus and open oesophagus
3 salivary glands
Parotid
Submandibular
Sublingual
Borders of the parotid gland
Extends anteriorly over the master
Inferiorly over the posterior belly of the digastric
Parotid duct: where it enters the mouth
Penetrates the buccinator and opens into the oral cavity adjacent to the crown of the 2nd molar
Parotid: secretion
Serous
Parotid: what it encloses
External carotid artery, retromandibular vein, extra cranial part of the facial nerve
Parotid: Innervation
Glossopharyngeal
Submandibular gland: where it opens
Opens out either side of the frenulum of the tongue
Submandibular gland: secretions
Serous
Submandibular gland: innervation
Facial nerve
Sublingual salivary ducts: positions
Along the submandibular duct into which some open
Sublingual salivary ducts: secretions
Mucous
Sublingual salivary ducts: innervation
Facial nerve
Muscles: elevation of the mandible
Masseter, temporalis, medial pterygoid
Muscles: depression of the mandible
Digastric, geniohyoid, mylohyoid
Muscles: protrusion of the mandible
Lateral pterygoid assisted by the medial pterygoid
Muscles: retraction of the mandible
Posterior fibres of the temporals, deep part of masseter, geniohyoid, digastric
Muscles of mastication
Masseter - elevates mandible
Temporalis - elevates and retracts mandible
Medial pterygoid - elevates, protracts and lateral movement of the mandible
Lateral pterygoid - depresses and protracts mandible to open mouth
Describe the tempero-mandibular joint
2 synovial cavities joined by a fibrocartliagenous disc
What do the lower and upper parts of the tempero-mandibular joint do
Lower joint cavity - depression and elevation of the mandible
Upper joint cavity - protrusion of the mandible
Actions involved in opening and closing the mouth
Opening - depressing and protruding the mandible
Closing - elevating and retracting the mandible
Side to side movements of the mandible are enabled by
Contralateral heads rotating on the inferior surface of the articular disc.
Identify major branches of the sternal carotid artery
Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior articular Maxillary Superficial temporal
The mandibular division of the trigeminal nerve exits the skull via…
foramen ovale
The mandibular division of the trigeminal nerve divides into the
Lingual nerve
Inferior alveolar nerve
Lingual nerve joins with
Facial nerve’s chords tympani
Which nerve is more anterior, lingual or inferior alveolar
Lingual
Lingual nerve innervates
Sensory innervation to the anterior 2/3 of the tongue, the floor of the mouth and the lingual gingivae
Inferior alveolar nerve passes through… and innervates
Mandibular canal
Forms the inferior dental plexus - sends dental branches to all mandibular teeth on its side
Path of the parotid duct
emerges through the anterior border of the gland, passes the master, turns medially, penetrates the buccinator, and opens into the mouth opposite the second upper molar.
Path of the facial nerve
Emerges from skull via the stylomastoid foramen in the temporal bone (via the internal acoustic meatus).
The extra cranial part enters the parotid gland (doesn’t innervate it), continues superficially and forms a plexus.
Branches of the facial nerve
Temporal – to frontal belly of occipitofrontalis
Zygomatic – to orbicularis oculi and upper face
Buccal – to buccinatorm orbicularis oris and mid face
Marginal mandibular – to orbicularis oris and the corner of the mouth
Cervical – to platysma
Bell’s palsy
a lower motor lesion of the facial nerve – lesion of cell bodies or the nerve itself causing the muscles of the face to sag on the affected side
A full set of adult teeth is
In each quadrant of the mouth, there are:
32
2 incisors
• 1 canine
• 2 premolars
• 3 molars
In a complete deciduous (baby) set there are
20
The first deciduous come at
complete at
6-8 months
20-24 months
Permanent adult teeth start at
Complete at
6 years
early 20s
