The oral cavity Flashcards
Describe the boundaries of the oral cavity. (5)
Walls - buccinator Roof - hard and soft palate Floor - tongue Anterior - oral fissure and lips Posterior - oropharyngeal isthmus.
Describe the oropharyngeal isthmus. (4)
An arch formed:
Superiorly by the soft palate
Inferiorly by the tongue
Laterally by the anterior (palatoglossus muscle) and posterior (palatopharyngeus) pillars of the fauces.
Where does the tonsilar fossa lie and what does it contain? (2)
Lies between the pillars of the fauces and contains the palatine tonsil.
Describe the internal muscles of the tongue. (4)
Lie entirely within the tongue, have no bony attachments, shape the tongue, and run in all directions.
Describe the extrinsic muscles of the tongue. (3)
Give some examples. (4)
Give their nerve supplies. (3)
Act to change the position of the tongue (protrusion, retraction, side to side, protraction).
Attach to the the hyoid/mandible inferiorly and the tongue/soft palate superiorly.
Genioglossal - protrudes tongue - tests function of cranial nerve XII
Hyoglossal
Styloglossal
Palatoglossal
All hypoglossal except palatoglossal which is vagus.
Describe the sensory innervation of the tongue. (5)
Posterior 1/3: glossopharyngeal nerve does general and special sensory, and carries parasympathetics to the parotid gland.
Anterior 2/3: general sensory is carried by lingual branch of Vc, and taste is carried by the chorda tympani branch of the facial nerve, and carries the parasympathetics for every othe salivary gland.
Describe what would be seen orally if you had hypoglossal or vagus never lesions. (4)
Hypoglossal - deviation on protrusion towards the side of the lesion - “lick the wound”
Vagus - deviation (weakness - failure to rise) on the OPPOSITE side of the soft palate. Uvula points to the healthy side.
Describe the anatomical location of the pharynx. (3)
Base of the skull to C6.
Superior part lies posterior to the nasal and oral cavities.
It’s posterior wall is covered with buccopharyngeal fascia, which leads to the retropharyngeal space.
Define the nasopharynx. (3)
Lies superior to the soft palate and anterior to C1. Eustacian tubes and pharyngeal tonsils (adenoids) exist here.
Define the oropharynx. (3)
From the soft palate to the epiglottis (C2-C3). The palatine tonsils lie either side between palatoglossus and palatopharyngeus.
Define the laryngopharynx. (3)
Epiglottis to the oesophagus at the level of the cricoid cartilage (C3-C6). On either side of the laryngeal inlet exists the piriform fossa.
Describe the walls of the pharynx. (4)
Externally
Superior, middle and inferior constrictors, all vagus nerve. Relax and contract sequentially to propel food into the oesophagus.
Internally
3 longitudinal muscles that work with the constrictors.
Explain the causes and symptoms of large pharyngeal pouches. (4)
The inferior constrictor of the larynx has two bellies, between which there’s a weakness called Killian’s dehiscence, which can herniate to form a pharyngeal pouch if pressure rises.
Small pouches can be asymptomatic, but large ones can present with dysphagia, regurgitation and neck lump.
Describe the nerve supply of the pharynx. (5)
Motor: vagus does all the muscles except stylopharyngeus which is glossopharyngeal. - why vagus is the efferent arm fo the gag reflex but glossopharyngeal is the afferent.
Nasopharynx: Vb
Oropharynx and Eustachian tube: glossopharyngeal
Laryngopharynx: vagus.
Describe how pathology of the tonsils can affect the pharynx. (3)
Adenoiditis can obstruct the nasopharynx and block the Eustachian tube causing mouth breathing and middle ear pathology.
