Oral and Nasal Cavities, Pharynx, Larynx and Thyroid Flashcards
what are the boundaries of the oral cavity
- from oral fissure (opening of lips) anteriorly to oropharyngeal isthmus posteriorly
- divided to vestibule (between cheeks and teeth) and mouth proper
what are the boundaries of the mouth proper?
- roof: hard and soft palate
- floor: muscular diaphragm (mylohyoid), geniohydoid muscle, tongue, salivary gland and duct
- lateral: cheeks- buccinator (facial n)
where is the hyoid?
C3
describe the structure of the hyoid
body, greater and lesser horns
what ligaments attach to hyoid?
- stylohyoid lig: from styloid process of temporal bone to lesser horn
- thyrohyoid: superior border of thryoid to post surface and greater horn
- hypoepiglottic: hyoid bone to the anterior aspect of the epiglottis.
what is the lingula of the mandible
- bony ridge surrounding the margin of the mandibular foramen
where is the thyroid cartilage
C4-C5
What is the structure of the thyroid cartilage?
- 2 sheets- laminae- joined anterior at laryngeal prominence- adams apple
- superior and inferior horns
- superior connected to hyoid by lateral thyrohoid lig
- inferior: cricothyroid ligament to cricoid carilage
what is the thyrohyoid membrane?
lateral and median thyrohyoid ligaments
where is the cricoid cartilage?
C6, inferior border of larynx
What is the structure of the cricoid cartilage
- complete ring of hyaline cartilage
- broad sheet posteriorly and narrow arch anteriorly
- sigent ring
- articulates with paired arytenoid cartilages posterioly
what is the epiglottis
- leaf shaped plate of elastic cartilage
- marks entrance to larynx
- stalk attaches to back of anterior aspect of thyroid cartilage
what are the arytenoid cartilages
- pyramidal shaped structures on cricoid cartilage
- apex: articulate with corniculate cartilage
- base: w/ superior border of cricoid
- 3 sides
- vocal process (anterior): attachment for vocal lig
- muscular process (posterior): attachment for posterior and lateral circoarytenoid muscle
- paired
what are the corniculate cartilages
- paired
- minor cartilaginous
- articulate with apices of arytenoid
what are the cuneiform cartilage
- pair
- in ary-epiglottic fold
- strength fold
what are the tracheal rings
- incomplete C shaped rings of cartilage that hold open the trachea
what is the hard palate?
where is it?
what bones make up the hard palate?
- horizontal bony plate
- anterior 2/3 of roof of oral cavity
- make of palatine process of maxilla and paired palatine bones
- separate oral and nasal cavity
what are the divisions of the pharynx
- nasopharynx: Base of skull to soft palate, continuous with nasal cavity, contains adenoid tonsils
- oropharynx: soft palate to superior border of epiglottis, post 1/3 of tongue, lingual tonsils at base of tongue, palatine tonsils, superior constrictpor muscle
- laryngopharynx: distal, superior border of epiglottis, inf border of cricoid, continuous with oesophagus
what is the pharyx and where is it
- muscular tube connecting oral and nasal cavity to larynx and oesophagus
- starts base of skull and ends at inferior border of cricoid cartilage C6
what is the larynx and where is it?
the organ of voice production, C3-C6
- connects inferior part of oropharynx with the trachea
what is the waldeyers ring
- ring of lymphoid tissue in naso- and oro-pharynx formed by paired palatine tonsils, adenoid and lingual tonsils
what are the muscles of the pharynx?
- circular: superior, middle and inferior constictors
- longitudinal: stylopharyngeus, palatopharyngeus, salpingopharyngeus
what is the function of the pharyngeal constrictors
- form incomplete muscular circle
- contract sequentially
- constrict lumen and propel food bolus inferiorly into oesophagus
what innervates the constrictor muscles
superior: pharyngeal branch of vagus nerve, pharyngeal plexus
middle and inferior: pharyngeal branch of vagus, pharyngeal plexus, external and recurrent laryngeal nerves
which nerves make up the pharyngeal plexus?
glossopharyngeal nerve CN IX and vagus nerve CN X
what is the origin of the external laryngeal nerve?
superior laryngeal nerve
explain the divisions of superior laryngeal nerve
splits in carotid sheath to internal and external laryngeal nerve
- is a branch of vagus nerve
what is the origin of inferior laryngeal nerve?
continuation of recurrent laryngeal nerve (branch of vagus)
what is the course of recurrent laryngeal nerve
right: under right subclavian artery
left: under aortic arch
What is the function of the longitudinal muscles of the pharynx
- shorten and widen pharynx
- elevate larynx during swallowing
whats the innervation of the longitudinal muscles of the pharynx?
- palatopharyngeus and salpingopharyngeus- pharyngeal branch of vagus CN X
- stylopharyngeus: glossopharyngeal CNix
what is the sensory innervation of the pharynx?
glossopharyngeal nerve
what is the blood supply of the pharynx?
- arterial from branches of external carotid
- ascending pharyngeal a
- branches of facial a
- branches of lingual and maxillary arteries
what is the venous drainage of the pharynx?
- pharyngeal venous plexus
- drains into internal jugular vein
what is the soft palate
- posterior of roof of oral cavity
- muscle fibre covered by mucous membrane
- anteriorly continuous with hard palate and palatine aponeurosis
- posterior: free, uvula
- palatoglossal arches and palatopharngeal arches
