S9) Functional Anatomy of the Oral Cavity, Tongue & Pharynx Flashcards
Identify and describe the borders of the oral cavity
- Roof: hard and soft palates
- Floor: muscular diaphragm & tongue
- Lateral walls: buccinators
Describe the anterior and posterior extensions of the oral cavity
- The oral cavity begins anteriorly at the oral fissure (bounded by lips)
- The oral cavity extends posteriorly to the oropharyngeal isthmus
The oropharyngeal isthmus is an arch in the oral cavity (continues into oropharynx).
Identify and describe its borders
- Superior: soft palate
- Below: upper surface of the tongue
- Sides: anterior and posterior pillars of the fauces
Which muscles form the anterior and posterior faucial pillars?
- Palatoglossus (anterior)
- Palatopharyngeus (posterior)
What do the palatopharyngeus and palatoglossus muscles do?
They contract during chewing to pull the soft palate down towards the back of the tongue, closing the oropharyngeal isthmus so food remains in the oral cavity while chewing
What is the tonsillar fossa and why is it significant?
The tonsillar fossa is the space between the two faucial pillars which contains the palatine tonsils (visible when inflamed)
The intrinsic muscles of the tongue only attach to other structures in the tongue.
What are the four paired intrinsic muscles of the tongue?
- Superior longitudinal muscle
- Inferior longitudinal muscle
- Transverse muscle
- Vertical muscle
Describe the function and innervation of the intrinsic muscles of the tongue
- Function: affect the shape and size of the tongue and have a role in facilitating speech, eating and swallowing
- Motor innervation: hypoglossal nerve (CNXII)
Identify the 4 extrinsic muscles of the tongue
- Genioglossus muscle
- Hyoglossus muscle
- Styloglossus muscle
- Palatoglossus muscle
What are the general functions of the extrinsic muscles of the tongue?
Extrinsic muscles allow protrusion, retraction and side-to-side movement of the tongue
What is the clinical significance of the genioglossus muscle?
The genioglossus muscle contracts to protrude the tongue and by its action, one can test the function of the hypoglossal nerve (CN XII)
Describe the motor innervation of the extrinsic muscles of the tongue
- Hypoglossal nerve (CN XII) – genioglossus, hyoglossus, styloglossus muscles
- Vagus nerve (CN X) – palatoglossus muscle
Describe the sensory innervation of the anterior 2/3 of the tongue
- Sensation – trigeminal nerve (CN V3)
- Taste – facial nerve (CN VII)
Describe the sensory innervation of the posterior 1/3 of the tongue
Sensation and taste – glossopharyngeal (CN IX)
What is the Wharton duct?
The submandibular duct (Wharton duct) is one of the salivary excretory ducts which drains saliva from each bilateral submandibular gland and sublingual gland to the base of the tongue
What is the Stensen duct?
The parotid duct (Stensen duct) is a duct and the route that saliva takes from the major salivary gland, the parotid gland into the mouth
What is Sialolithiasis?
Sialolithiasis (salivary gland stones) is a condition where a calcified mass / sialolith forms within a salivary gland, usually in the duct of the submandibular gland
Salivary gland stones reduce salivary flow.
Other than dehydration, what symptoms are experienced?
- Pain in gland
- Swelling
- Infection
How is Sialolithiasis diagnosed?
- History
- X-ray
- Sialogram
What is tonsillitis?
Tonsilitis is the recurrent inflammation of the tonsils (especially palatine tonsils) due to a virus or bacteria, often requiring a tonsillectomy (less common)
Identify 5 symptoms of tonsillitis
- Fever
- Sore throat
- Pain/difficulty swallowing
- Cervical lymph node enlargement (jugulo-digastric)
- Bad breath
What is a peritonsillar abscess?
- A peritonsillar abscess is a bacterial infection that usually begins as a complication of untreated strep throat or tonsillitis
- It generally involves a pus-filled pocket that forms near one of your tonsils
Identify 5 symptoms of peritonsillar abscesses
- Severe throat pain
- Fever
- Bad breath
- Drooling
- Difficulty opening mouth
What is the pharynx and where is it found?
- The pharynx is a muscular tube arising from the base of the skull down to the level of C6
- It forms the upper part of the alimentary canal and lies posterior to the nasal and oral cavities
Describe the fascial covering of the pharynx
The posterior wall of the pharynx is covered with buccopharyngeal fascia and lies against the prevertebral layer of the deep fascia
What are the boundaries of the nasopharynx?
- Superior: base of skull
- Inferior: upper border of soft palate
- Posterior: C1-C2 vertebrae
- Anterior: nasal cavity
What is found in the nasopharynx?
- Pharyngeal tonsils (adenoids)
- Orifice of the Eustachian tube
What are the boundaries of the oropharynx?
- Superior: soft palate
- Inferior: epiglottis
- Anterior: oral cavity
- Posterior: C2-C3 vertebrae
What is found in the oropharynx?
Palatine tonsils (in tonsillar fossa)
What are the boundaries of the laryngopharynx?
- Superior: oropharynx / epiglottis
- Inferior: oesophagus / cricoid cartilage
- Anterior: laryngeal inlet
- Posterior: C4-C6 vertebrae