Upper airways, mouth, pharynx and oesophagus Flashcards
Where is the upper airways?
Part of the respiratory tract above the trachea
What bones form the skull?
Frontal bone (forehead)
Parietal and occipital bones (lateral and posterior)
Sphenoid, temporal, occipital make up the floor of skull
What are the three parts to the temporal bone, which is the hardest and what do each form?
Squamous (lateral wall of skull), zygomatic (cheek bone), petrous (hardest: auditory and vestibular sensory systems)
Why is the petrous part necessary to be hard?
Protect the internal carotid artery and auditory mechanics that runs through/near to it.
What is located in the sphenoid bone?
Pituitary fossa
What does greater wing of sphenoid bone form, what is clinically significant about this part?
Lateral part of skull called the pterion, most fragile part of the skull
What do lateral pterygoid plates offer attachment for?
Jaw muscles
What are the bones (regions) of the facial skeleton?
Orbit, nose, upper jaw and lower jaw
What is the orbit and what makes it up
The orbit is the bony protective socket for the eye and is formed by the surrounding frontal, sphenoid, maxilla and zygomatic bones. As well as,
Ethmoid bone.
Palatine bone.
Lacrimal bone.
What forms the nose skeleton?
Two nasal bones, and the ethmoid bone forms the roof of nose and part of nasal septum. Lateral wall by maxilla
How is zygomatic arch of cheek formed?
Zygomatic bone joins maxilla and temporal bone
What forms the upper jaw?
Two maxilla bones
What does the lower jaw comprise?
Mandible
What does mandible articulate with?
Temporal bone (temporomandibular joint)
Two roles of the nose
Olfaction
Warming/filtering inspired air
Where does air enter nose?
Via nostrils (anteiror nares) passing between anteiror nasal hairs (vibrissae)
How does epithelium lining change after entering the nose?
From keratinised to mucous respiratory epithelium (pseudostratified and ciliated)
True or false, mucous membrane often continuous with underlying bone in nasal area
True
How does the nose warm air?
Rich blood supply warms and moisturises air
Describe the nasal mucosa blood supply
Branches of maxillary, facial and opthalmic artery (all from internal/external carotids)
What forms the nasal septum?
Bony vomer, septal/perpendicular plate of ethmoid (posteriorly) and septal cartilage (anteriorly)
What do the three conchae do?
Increase surface area of nasal
epithelium
Increase turbulence of air flowing through nasal cavity which enhances moistening and warming of passing air and increases change of trapping particles
What are conchae formed by?
Bony ridges
What happens to air as it enters the airways and reaches conchae?
It is obstructed by conchae hence increased turbulence
What are the superior and middle conchae part of?
Ethmoid bone
Describe the two types of mucous membrane lining nasal cavity
Respiratory epithelium
Olfactory epithelium
How does nose perform olfaction?
Olfactory epithelium found in upper part of nasal cavity above superior conchae and is specialsied for detecting smell
What happens to air as it exits the nose?
Exits through posterior openings (right and left choanae i.e. postieror nares) to enter nasopharynx
What are paranasal air sinuses?
Hollow air filled bony cavities that surround nasal passage
What are three functions of paranasal air sinuses?
Humidfy inspired air
Reduce weight of face
Add resonance to voice
What are the 4 pairs of paranasal sinuses?
Frontal, maxillary, ethmoidal, sphenoidal
What are meati?
Openings below each concha
What is the opening above the superior concha known as?
Spheno ethmoidal recess
What are paranasal sinuses lined by, where do they drain?
Respiratory mucosa secreting mucus that drains into nasal cavity behind conchae via meati
What is each sinus drained by?
Sphenoidal - Sphenoethmoidal recess
Posterior ethmoidal - Superior meatus
Maxillary, frontal and anterior/middle sinuses - Middle meatus
What does nasolacrimal duct do?
Drains tears into nasal cavity (to inferior concha, i.e. nose)
Infection and inflammation of Which sinus causes toothache?
Maxillary
Where do arteries supplying nose anastomose?
Little’s area in anterior nasal septum
What arteries supply roof, anterior and lateral walls of nose?
Anterior and posteiror ethmoidal arteries
What supplies meati, septum and conchae?
Sphaenopalatine arteries, superior labial artery + branch of greater palatine artery
Describe the sensory innervation to the nose
Trigeminal (V) nerve
Describe what innervates the olfactory epithelium
Olfactory nerve (I)
What supplies the parasympathetic innervation of the mucosal glands?
Pterygopalatine ganglion which is supplied with pre-gang fibres from facial (VII) nerve
What are the lips and oral cavity innervated by?
Trigeminal nerve
What is oral cavity formed by?
Maxilla, mandible
Soft and hard palate
Buccinator muscle (lateral walls)
Anterior bellies of digastric muscles below mylohyoid muscle (forms floor)
What forms the hard palate (anterior 2/3 of palate)?
Palatine process of maxillary bone and horizontal palates of palatine bone
What does the hard palate separate?
Oral and nasal cavities
What is soft palate?
Fold of mucous membrane containing tensor/levator platini muscles which lift soft palate in swallowing and pronation
Which muscle raises soft palate in swallowing and pronation?
Tensor/levator platini muscles
What does oral cavity then lead onto?
Leads to pharynx
What innervates hard palate and upper teeth?
Trigeminal maxillary branch
What innervates Cheeks, Floor of mouth, lower teeth?
Trigeminal mandibular nerve
What causes cleft palate?
Failure of fusion of maxilla at midline
What sort of joint is the temporomandibular joint?
Synovial hinging/sliding joint allowing opening and closing of mouth
What does the temporomandibular joint contain that makes it unique?
Fiborcartilaginous disc
Which three muscles close the jaw?
Temporalis
Masseter
Medial pterygoid (including side to side movements)
What muscle opens the jaw?
Lateral pterygoid
What are the muscles of mastication innervated by?
Mandibular branch of trigeminal nerve
What does the mylohyoid do?
Depresses the mandible
All muscles of tongue apart from palatoglossus are innervated by which nerve?
Hypoglossal nerve (XII)
Which nerve innervates the palatoglossus?
Vagus
What do intrinsic muscles of the tongue do?
Change the shape of the tongue
What do extrinsic muscles of tongue do?
Anchor tongue to bones around mouth so move tongue around
What are the names of the extrinsic muscles and principle actions?
Genioglossus - protrude and lifts up tip tongue
Styloglossus - Elevates and retracts
Hyoglossus - Depresses and retracts
Palatoglossus - elevates posterior tongue
Which nerves innervate anterior 2/3 of tongue providing sensation?
Trigeminal (general sensation) and facial (taste)
Which nerve innervates posterior third of tongue (both taste and general sensory)?
Glossopharyngeal (IX)
What are the two purposes of saliva?
Contains amylase for carbohydrate breakdown
Lubricant
What are the three types of salivary glands?
Parotid, submandibular, sublingual
What is parotid gland controlled by?
Otic ganglion (para preganglionic innervation from glossopharyngeal nerve)
Where do ducts of parotid, submandibular and sunlingual glands open to?
Back of mandible, under and at side of tongue respectively
Describe innervation of submandibular and sublingual salivary glands
Parasympathetic innervation by postganglionic nerves of submandibular ganglion
Preganglionic innervation of this is from facial nerve (VII)
Which vertebral level does pharynx extend to and from?
C1-C6
Where does the pharynx extent to and from?
Base of skull to oesophagus
What does pharynx do?
Provide path for food from oral cavity to oesophagus and air from nasal cavity to trachea
What is pharynx formed from?
3 constrictor muscles (superior, middle and inferor) which are fused posteriorly as raphe)
What is superior constrictor of pharynx attached to?
Medial pterygoid plate (sphenoid)
What is middle constrictor of pharynx attached to?
Hyoid bone
What is inferior constrictor of pharynx attached to?
Thyroid cartilage and cricoid cartilage
What is the sphincter between the pharynx and oesophagus?
Cricopharyngeus
What do muscles of pharynx receive innervation from and what do they do?
Pharyngeal plexus (vagus) Peristaltic contractions in response to receptors in upper part of oropharynx
How is nasopharynx protected from regurgitation of food in swallowing?
Soft palate rises upwards, closing it off from rest of nasopharynx from rest of pharynx
Where is oropharynx found?
Behind the mouth, between soft palate and hyoid bone
What does oropharynx do upon receiving food?
Involuntarily contracts, squeezing bolus into laryngopharynx and into oesophagus
What does oropharynx contain between palatoglossal and palatopharyngeal arches at back of throat?
Palatine tonsils
Where does laryngopharynx extend to?
Epiglottis to C5 (terminating at start of oesophagus)
Describe arterial blood supply to pharynx
Branches from external carotid and superior thyroid
Describe venous drainage of pharynx
Pharyngeal venous plexus drains into internal jugular vein
Describe the sensory innervation of the pharynx
Glossopharngeal to oropharynx
Trigeminal (maxillary division) to nasopharynx
Vagus to laryngopharynx
Describe the motor innervation of the pharynx
Vagus
What are the roles of the larynx
Produces speech and sound, protects trachea and bronchial tree in swallowing
What is larynx compromised of?
9 cartilages bound by ligaments and muscles and contains vocal cords
What is the importance of U shaped hyoid bone?
Framework by which larynx attaches to other structures in neck e.g. pharynx, mandible, tongue
What level is the hyoid bone?
C3-C4
What is the epiglottis
Elastic flap of cartilage that forms entrance to the larynx
What is opening of larynx formed by?
Aryepiglottic folds
Which cartilage forms the Adams apple?
Thyroid cartilage
What shape is the thyroid cartilage?
V shape
Which cartilage is the only complete ring of cartilage in the respiratory system?
Cricoid
Describe the innervation of the larynx
Laryngeal structures above vocal cord (supraglottic): superior/interior laryngeal nerve (sensory innervation)
Below vocal cord (subglottic) recurrent laryngeal nerve
Describe blood supply to larynx
Superior laryngeal branch from superior thyroid artery (above cord structures)
Inferior laryngeal branch from inferior thyroid artery (below cord)
What is the name for the opening between the true vocal cords and the arytenoid cartilages of the larynx?
Rima glottides
Why is the rima glottides significant?
Its area is constantly changing in vocalisation
What is the false vocal cord, what forms it?
Superior vestibular fold forms it
Protective role (closes glottis in swallowing)
What forms true vocal cord, what is it for?
Inferior vestibular fold
Important for vocalisation (air flows between vocal cords and vibrates them)
Describe three divsions of the larynx
Supraglottic
Glottic (between 2 types of vocal cords)
Subglottic
What determines loudness of voice?
Force of air passing between vocal cords and separation of vocal cords
Intrinsic laryngeal muscles move/rotate arytenoid cartilages) and thus affect separation of vocal cords
Which nerve supplies muscles that abduct/adduct (motor) vocal cord/glottis?
Recurrent laryngeal nerves
What determines pitch?
Tension in vocal cords
What happens when we swallow?
The tip of the tongue is elevated against the hard palate and the posterior part of the tongue depressed, bolus moves to the oro-pharynx.
The sensory receptors on the posterior part of the tongue (glossopharyngeal) initiate a swallowing reflex.
The soft palate is tensed and elevated, sealing the nasal part of the pharynx. The hyoid bone is elevated (epiglottis to cover larynx opening) as the bolus passes to the pharynx, where the pharyngeal constrictors force the bolus down toward the oesophagus.
Once past the cricopharyngeus muscle, the hyoid descends and the epiglottis flips back to reopen the airway.
The sensory component of the gag reflex is given by which nerve?
Glossopharyngeal nerve
The margins of the inlet to the larynx …
Epiglottis and ary-epiglottic folds
The sensory innervation of the vestibule of the larynx…
Superior/Internal laryngeal branch of the vagus nerve
The nasal cavity has a prominent submucous venous plexus…
True
The pharynx is mainly lined by a non-keratinised stratified squamous epithelium…
True
What do olfactory sensory nerves pass through?
Cribiform plate
What cranial nerve allows protrusion of the tongue?
Hypoglossal
What tongue muscle is not innervated by the hypoglossal nerve?
Palatoglossus (Vagus)
Where does the naso lacrimal duct enter the nasal passage ?
Beneath the inferior concha
Where is the maxillary sinus in close proximity to?
The roots of the teeth of the upper jaw
What is the role of the pharyngo tympanic tube?
Allows pressure equalisation across the tympanic membrane
T/F the nasal conchae increase the surface area of the nasal passage to enhance the sense of olfaction
False
Cranial nerve controlling lacrimation
Facial
Ganglion supplying post ganglionic fibres to the nasal mucosa
Pterygopalatine
Where is the parotid duct?
Through the buccinator muscle
What muscle controls the pitch?
Cricothyroid
Muscle which opens the vocal folds?
Posterior cricoarytenoid
All intrinsic laryngeal muscles except posterior cricoarytenoid …
Close the vocal folds
Floor of mouth muscles and innervation
Superficial digastric, the mylohyoid innervated by V3, geniohyoid (hypoglossal)
Genioglossus shape
Fan shaped
Sensory innervation of the upper palate
V2 hard, glossopharyngeal soft
Arches at the back of mouth and relative position
Lateral anterior palatoglossal arch, medial palatopharyngeal
What is found around the parotid gland?
Facial nerve, division / termination of external carotid, retromandibular vein
What artery passes over the submandibular gland?
Facial
Processes on mandible
Coronal and condylar
Temporomandibular joint consists of
Head of mandible, glenoid fossa, intra-articular disc
Opening of mouth muscles
Lateral pterygoid, digastric depresses
Oropharynx between
Soft palate and the epiglottis
What is the retropharyngeal space?
Posterior to pharnyx and oesophageal posterior walls extends from skull base to thoracic spine contains areolar fat and lymph nodes
What is the Danger space?
Posterior to the retropharyngeal space extending from skull base to posterior mediastinum
Why is danger space called danger space?
Direct communication with posterior mediastinum and free L/R communication - sepsis and infection risk
Involuntary rapid swallowing phase
Soft palate muscles contract to seal off the nasopharynx, pharynx widens while the larynx is elevated by suprahoid muscles, larynx shuts and epiglottis covers, then contraction of the pharyngeal constrictors pushes food into oesophagus
Voluntary phase of swallowing
Muscles of mastication and extrinsic / intrinsic tongue muscles create bolus and push into oropharynx
Soft palate muscles and innervation
Tensor veli palatini (trigeminal v3) Levator veli palaitini (vagus)
