The Mouth and Pharynx Flashcards
What are the borders of the oral cavity?
Upper and lower teeth
Floor of mouth/tongue
Oropharynx
Hard palate and soft palate
What is the oral vestibule?
The space between the lips and teeth
What structures are found in the floor of the mouth?
Deep lingual vein
Frenulum
Sublingual caruncle
Sublingual fold
What are the muscles of the floor of the mouth and what is their innervation?
Geniohyoid - C1 via hypoglossal nerve
Mylohyoid - CN V3
Which muscle of the floor of the mouth has a free border and why is this clinically significant?
Mylohyoid
Potential space for transfer of infection
What are the major salivary glands?
Bilateral pairs:
Parotid
Submandibular
Sublingual
What are the minor salivary glands and what is their function?
1000’s in oral mucosa
Basal secretion to keep mouth moist
What stimulates salivation?
Thought, site, smell of food or presence of food in the mouth
Painful oral conditions (teething or fracture)
What is the surface anatomy of the parotid duct?
Parotid duct crosses face and secretes into mouth by upper 2nd molar
What is the surface anatomy of the submandibular duct?
Submandibular duct enters floor of mouth and secretes via lingual caruncle
What is the surface anatomy of the sublingual gland?
Sits n floor of mouth and secretes via several ducts superiorly
What is the potential consequence of duct clogging/blockage?
Swelling due to a back up of secretions
What is the innervation of the submandibular and sublingual salivary glands?
Parasympathetic from CN VII
Chorda tympani connects to lingual nerve branch of CN V3
What is the innervation of the parotid gland?
Parasympathetic from CNIX
Hitches a ride on branches of CN V3 (auriculotemporal branch)
What is the basic histology of the tongue?
Made from skeletal muscle
Covered in mucosa
Where is the posterior 1/3 of the tongue and what is it’s innervation?
Vertical part - not in oral cavity
Taste and general sensory by CN IX
Where is the anterior 2/3 of the tongue and what is it’s innervation?
Horizontal part - in oral cavity
General sensory by CN V3
Taste by CN VII
What papillae are found in the tongue and what are their functions?
Foliate, vallate and fungiform = Taste buds
Filliform = Touch, temperature
What structure divides the tongue into its anterior and posterior portions?
Sulcus terminalis
What is found at the apex of the sulcus terminalis?
Foramen caecum
Where does the thyroid originate and how does it get to its final destination?
Originates in pharynx and descends through foramen caecum of tongue
What are the 4 pairs of extrinsic muscles of the tongue?
Palatoglossus
Styloglossus
Genioglossus
Hyoglossus
What is the function of the extrinsic muscles of the tongue?
Change the position of the tongue during mastication, swallowing and speech
How many intrinsic muscles of the tongue are there and where are they found?
4 pairs
Mainly dorsally/posteriorly
What is the function of the intrinsic muscles of the tongue?
Modify the shape of the tongue during function
What is the innervation of the tongue muscles?
All = hypoglossal nerve
Except palatoglossus = Vagus
What is the CNS connection of hypoglossal nerve?
Medulla oblongata
Through which foramina does the hypoglossal nerve exit the base of the skull?
Hypoglossal canal
found in anterior all of foramen magnum
What is the extra cranial course of the hypoglossal nerve?
Descends in neck lateral to carotid sheath
At level of hyoid passes anteriorly to lateral aspect of tongue
What is the clinical test for the hypoglossal nerve?
Ask the patient to stick their tongue straight out
NORMAL = Tip in midline
UNILATERAL CNXII DAMAGE = Tip of tongue points towards the side of the injured nerve
What is the blood supply to the tongue?
Lingual artery
Where are arteries and nerves found in relation to the tongue?
Arteries pass medial to hypoglossus
Nerves pass lateral to hypoglossus
What is the gingivae?
Mucosa covering the alveolar bone
What passes through the greater and lesser palatine foramina?
Branches of CN V2
Branches of maxillary a.
What is the pterygoid haulus?
Projection of the medial pterygoid plate of sphenoid bone
What are the muscles of the soft palate?
Tensor veli palatini Levator veli palatini Palatopharyngeus Palatoglossus Musculus uvulae
What is the function of tensor veli palatini?
Tenses palatine apopneurosis
What is the function of elevator veli palatini?
Lifts palatine apopneurosis
What is the function of palatopharyngeus?
Lifts pharynx and thyroid cartilage
What is the function of palatoglossus?
Brings tongue and soft palate together
What is the function of muscles uvulae?
Shortens uvula
What is the innervation of the skeletal muscles of the soft palate?
CN X (vagus) Exception: Tensor veli palatini - CN V3
What is the function of the soft palate?
Stops food entering nose while swallowing
Directs air into nose or mouth during speech, sneezing, coughing, vomiting
Helps close off entrance into oropharynx during gag reflex
What is the clinical test for the vagus nerve?
Ask patient to say “aaah”
NORMAL = Uvula lifts straight in midline
UNILATERAL NERVE PATHOLOGY = Uvula pulled away from the non functioning side
What is the function of the outer circular muscles of the pharynx?
During sequential contraction, push food bolus inferiorly towards oesophagus
What is the function of the inner longitudinal muscles of the pharynx?
During contraction, pulls larynx superiorly shortening pharynx during swallowing
What are the circular muscles of the pharynx?
Superior constrictor
Middle constrictor
Inferior constrictor
What is the innervation of the muscles of the pharynx?
All = CNX
Exception: Stylopharyngeus = CN IX
What is the “Gateway to mouth” ?
Formed by gaps between the circular muscles of the pharynx
CN IX, Lingual artery and stylopharyngeus muscle pass here
What is the common insertion of the circular constrictors of the pharynx?
Midline raphe
What are the longitudinal muscles of the pharynx?
Stylopharyngeus
Palatopharyngeus
Salpingopharyngeus
What is the common insertion of the longitudinal muscles of the pharynx?
Posterior border of thyroid cartilage
What is the origin of the superior constrictor of the pharynx?
Pterygoid hamulus
Pterygomandibular raphe
Mylohyoid line
What is the origin of the middle constrictor of the pharynx?
Greater horn of hyoid
What is the origin of the inferior constrictor of the pharynx?
Thyroid cartilage (oblique line) Cricoid cartilage
What is the origin of Stylopharyngeus?
Styloid process
What is the origin of Palatopharyngeus?
Palate
What is the origin of Salpingopharyngeus?
Cartilage of pharyngotympanic tube
What are the components of Waldeyer’s Tonsillar Ring?
Pharyngeal tonsil (Adenoid)
Tubal tonsil
Palatine tonsil (The Tonsil)
Lingual tonsil
What is the function of Waldeyer’s Tonsillar Ring?
Defence against invading pathogens
Where is Waldeyer’s Tonsillar Ring located?
Within the mucosa of the nasopharynx and oropharynx
What are the regional lymph nodes associated with the mouth/salivary glands/pharynx?
Retropharyngeal nodes Jugulo-digastric node Deep cervical nodes Submental nodes Submandibular nodes
Which lymph nodes drain the tip of the tongue?
Submental
Which lymph nodes drain the parotid gland?
Jugulo-digastric node
What are some of the features of an infected lymph node?
Swollen Painful Soft Smooth Not fixed to adjacent structures Improve rapidly with antibiotics etc.
What are some of the features of a lymph node due to cancer?
Swollen Not painful Hard Irregular Fixed to adjacent structures Do not improve
Why must examination of the head and neck lymph nodes be bilateral?
Midline structures often drain bilaterally
What are the bilateral regional lymph nodes to be examined?
Submental Submandibular Parotid (pre auricular) Mastoid (post auricular) Occipital Deep cervical (along IJV) Superficial cervical (along EJV)
