Oral cavity and upper GIT Flashcards
Describe the location of the Palatine tonsil
Between soft palate and back of tongue
Recall the boundaries of the nasopharynx, oropharynx and laryngopharynx
Nasopharynx = Pharyngeal tonsil --> inferiormost point of soft palate Oropharynx = --> top of epiglottis Laryngopharynx = --> inferior border of cricoid cartilage
What is found at the bifurcation of the oropharynx where the trachea and oesophagus begin?
Transverse arytenoid muscle
How can the oropharynx and nasopharynx be sealed off from one another?
Depression of pharyngeal isthmus
What is the main characterising feature of the oropharynx?
Lymphatic ring of lingual, pharyngeal and Palatine tonsils
Recall the movement of the epiglottis during swallowing
Retroflexes to cover trachea
What is the clinical relevance of the inlet of the larynx?
There is a bilateral piriform recess in which foreign bodies may become lodged
Describe the muscles of the pharynx
Constrictor muscles (circular) = sup, med and inf; sequentially contract superoinferiorly Longitudinal muscles (vertically arranged) = elevate pharyngeal wall to bring it up and over a bolus of food during swallowing
Describe the muscular arrangement of the tongue
Intrinsic and extrinsic paired muscles, separated by median saggital septum
Describe the motor inneravtion of the tongue
Palatoglottus = CNX, all others = CNXII
Recall the origin, insertion and function of the intrinsic muscles of the tongue
Origin and insertion = within substance of tongue
Function = alter tongue shape
Recall the extrinsic muscles of the tongue
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
Recall the sensory innervation of the pharynx
Pharyngeal plexus (CNIX/X)
Recall the function of styloglossus
Lift and retract tongue
Recall the function of palatoglossus
Bolus –> oropharynx
What must be relaxed in order to open the oesophagus?
Cricopharyngeus
Recall the 3 salivary glands, their innervation and the composition of their secretions
- Parotid, CNIX, serous
- Submandibular, CNVII, serous
- Sublingual, CNVII, mucous
Briefly summarise the location of each of the extrinsic tongue muscles
Immediately behind body of tongue = palatoglossus
Just behind that = styloglossus
Originating just behind the mandible and projecting superiorly = genioglossus
Describe the sensory innervation of the tongue
Anterior 2/3: sensation = V3, taste = VII
Posterior 2/3: sensation + taste = IX
Recall the 4 main muscles of mastecation
Superficial: Masseter Temporalis Deep: Lateral pterygoid Medial pterygoid
Recall the origin and insertion of masseter
Zygomatic arch to ramus and angle of mandible - superficial and deep parts
What is the function of masseter?
Elevation of mandible to force closure of mouth
Recall the origin and insertion of Temporalis
Temporal fossa to mandibular coronoid process
What is the function of Temporalis?
Elevates and retracts mandible
Recall the origin and insertion of the lateral pterygoid muscle
Top of neck of mandible to sphenoid plate
Recall the origin and insertion of the medial pterygoid muscle
Maxilla to angle of mandible
What does the medial pterygoid overlie?
Buccinator
What is the function of lat. pterygoid?
Depresses and protracts mandible to open mouth
What is the function of med. pterygoid?
Acts on mandible to allow chewing: elevation, protraction and lateral movement
Summarise the structure of the temperomandibular joint
Superior --> inferior: Temporal tubercle Mandibular fossa Articular disc Joint capsule Head of mandible
Which action of the TMN predominates in slight opening of the jaw?
Hinge action
Which action of the TMN predominates in wideopening of the jaw?
Hinge AND GLIDING movements
Recall the order of the 8 branches of the external carotid artery
She Always Likes Friends Over Papa, Sister, and Mama Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior Auricular Superficial temporal Maxillary
Recall the branches of the facial nerve, from superior to inferior
Temporal Zygomatic Buccal Mandibular Cervical
Describe the path of the parotid duct
Penetrates buccinators and opens into the oral cavity adjacent to 2nd upper molar
Which nerve innervates the parotid gland?
IX
Where does the submandibular gland lie (2 descriptions)?
Along body of mandible
Partly superficial and partly deep to nylohyoid
Where does the submandibular duct open out?
Either side of frenulum of tongue
Describe the location of the sublingual glands
Scattered along the submandibular duct into which some of them open
Recall the innervation of the muscles of mastecation
Mandibular branch of trigeminal (V3)
Recall the function of buccinator
Presses cheeks against molars when chewing
What sort of tissue makes up the articular disc of the TMJ?
fibrocartilaginous
Describe the origin of the lingual nerve?
Main origin = V3, exits via foramen ovale
Also a contribution from facial nerve through chorda tympani
Which nerve is the main contributor to the inferior dental plexus?
Inferior alveolar nerve
How many teeth in a full adult set? Recall how many of each type
32 including wisdom teeth: Per quadrant: 2 incisors 1 canine 2 premolars 3 molars
Describe where you would test each of the dermatomes of the face
V1 = forehead V2 = Between nose and lip, or cheek V3 = Chin or more lateral cheek
