HNN Topic 18 - Pharynx, Larynx, Tonsils, Nose and Ear Flashcards
(111 cards)
1
Q
List the intrinsic muscles of the larynx and describe their functions
A
- Cricothyroid muscle - stretches and tenses vocal ligaments (forceful speech)
- Thyroarytenoid muscle - relaxes vocal ligament (soft speech)
- Posterior cricoarytenoid muscle - abducts vocal ligament
- Lateral cricoarytenoid muscle - adducts vocal ligament
- Transverse and oblique arytenoid muscles - adducts vocal ligament
2
Q
What is the function of the larynx?
A
Phonation, cough reflex, protection of lower respiratory tract
3
Q
Describe the areas of the nasal cavity
A
- Vestibule - surrounds anterior external opening to nasal cavity
- Respiratory region - lined by ciliated pseudostratified epithelium (respiratory), mucous secreting goblet cells
- Olfactory region - at apex of nasal cavity, lined by olfactory cells
4
Q
What is the function of the intrinsic muscles of the larynx?
A
Control shape of rima glottidis and length/tension of vocal folds for phonation
5
Q
How can the vestibuloocular reflex be tested?
A
Barany chair or caloric stimulation
6
Q
Describe how the inner ear functions in balance
A
- Vestibular apparatus = semi-circular canals and otolith organs (utricle and saccule)
- Semi-circular canals detect angular acceleration in 3 planes due to orientation in 3 different planes - superior, horizontal + posterior
- Otolith organs detect linear acceleration (horizontal and vertical) and orientation in a gravitational field
- Vestibular receptors - hair cells, affected by movement of endolymph
7
Q
Describe the lining and location of the oropharynx
A
- Lined by stratified squamous non-keratinised epithelium
- From edge of soft palate to tip of epiglottis
8
Q
List the treatment/management options in otitis media with effusion
A
- Active observation (6-12 weeks)
- Hearing aids
- Autoinflation/Valsalva manoeuvre
- Surgical - myringotomy and ventilation tube (Grommet) insertion
9
Q
If things become stuck in the throat (e.g. fish bones), where are they likely to be lodged?
A
In the vallecula/piriform fossa
10
Q
What is the function of the fenestra vestibuli and the fenestra cochlea?
A
- Fenestra vestibuli - stapes moves in and out of in response to vibration
- Fenestra cochlea - fluid pushed by footplate of stapes bulges here (2nd tympanic membrane)
11
Q
List the risk factors for otitis media with effusion
A
- Bottle-fed
- Parental smoking
- Group nursery
- Atopy e.g. eczema, asthma
- Genetic disorders
- Mucociliary e.g. cystic fibrosis, primary ciliary dyskinesia
- Craniofacial e.g. Down’s syndrome, cleft palate
12
Q
Describe the structure of the palatine tonsils
A
- Covered by stratified squamous epithelium
- Penetrated by 15-20 crypts - contains lymphocytes, bacteria and desquamated epithelial cells
13
Q
What is the function of the vestibuloocular reflex?
A
Stabilise images on the retina during movements - eyes move against direction of rotation of head
14
Q
Describe the boundaries of the nasal cavity
A
Vestibule to nasopharynx
15
Q
What is the function of the sphenopalatine foramen?
A
At the level of the superior meatus, allows communication between the nasal cavity and the pterygopalatine fossa, sphenopalatine artery, nasopalatine and posterior superior lateral nasal nerve pass through
16
Q
What is the function of the inner ear?
A
Hearing and balance
17
Q
Describe the contents of the mastoid antrum
A
Mastoid air cells - can become infected ( =mastoiditis)
18
Q
What causes sensorineural deafness?
A
- Nerve deafness- damage to nerve or inner ear (hair cells)
- Aging, ototoxicity, loud noise, tumours
19
Q
What is the function of the nose?
A
Olfactory and respiratory
- Warms/humidifies air
- Removes and traps pathogens/particulate matter from inspired air
- Sense of smell
- Drains paranasal sinuses and lacrimal ducts
20
Q
Describe the parts of the middle ear
A
- Tympanic cavity - contains ossicles
- Epitympanic recess - superior to tympanic cavity, next to mastoid antrum
- Auditory tube - connects middle ear to nasopharynx
- Fenestra vestibuli
- Fenestra cochlea
21
Q
Where is the incisive canal and what is its function?
A
Between nasal cavity and incisive fossa of the oral cavity, transmits nasopalatine nerve and greater palatine artery
22
Q
Where are the corniculate cartilages found?
A
Articulate with the apex of the arytenoid cartilage
23
Q
How is autoinflation/Valsalva manoeuvre used in treatment of otitis media with effusion?
A
- Valsalva manoeuvre = blow out air against pressure (with nose pinched/mouth shut)
- Equalises pressure in middle ear, allows ventilation and drainage of fluid
- Done if child is old enough
- Young children - autoinflation
- Blow up balloon via nostril to equalise pressure
24
Q
Describe the aetiology/pathogenesis of otitis media with effusion in children
A
- Combination of inflammatory changes and auditory tube dysfunction
- Upper respiratory infection - inflammation of tonsils, tubal tonsil inflammation causes occlusion of auditory tube
- Negative pressure due to occlusion of the auditory tube - fluid accummulation
- Children’s auditory tubes are shorter + more horizontal, more susceptible to infection/occlusion
25
What is the Weber test used for?
* Detect unilateral conductive/sensorineural hearing loss
* Tuning fork placed in the middle of the forehead - compare volume in each ear
* Normal - symmetrical
* Abnormal
* Conductive - louder in defective ear
* Sensorineural - louder in normal ear
26
Describe how the inner ear functions in hearing
* Cochlea detects magnitude/frequency of sound waves
* Inner hair cells of organ of Corti activate ion channels in response to vibration of the basilar membrane
* Action potential from spiral ganglia (cell bodies of cochlear nerve)
* Higher magnitude of sound waves = more action potentials
27
Describe the blood supply of the lingual tonsils
Lingual artery, tonsillar branch of external carotid artery
28
Describe the location of the tonsils
Waldeyer's ring of tonsil tissue - around oropharynx
29
Describe the location and structure of the pharyngeal tonsils
* Adenoids, in superior nasopharynx
* Covered by pseudostratified columnar epithelium (respiratory)
* No crypts
30
Describe the venous drainage of the palatine tonsil
Internal jugular vein via peritonsillar plexus of the lingual/pharyngeal veins
31
Describe the clinical signs which would be seen in conductive deafness
* Rinne test negative - bone conduction \> air conduction
* Absolute bone conduction normal
32
Describe the blood supply of the nasal cavity
* Branches of internal and external carotid arteries
* Internal - anterior and posterior ethmoidal arteries, branches of ophthalmic artery, come through cribiform plate
* External - sphenopalatine, greater palatine, superior labial and lateral nasal arteries
* Veins follow arteries, drain into pterygoid plexus, facial vein or cavernous sinus
33
Where are the tubal tonsils found?
On tubal elevation, surrounds the opening to the auditory tube
34
What is the clinical significance of the relationship between the paranasal sinuses and the nasal cavity?
* Upper respiratory tract infection can spread to sinuses, causes inflammation (swelling and pain) of mucosa - sinusitis
* More than one sinus affected = pansinusitis
* Maxillary nerve supplies maxillary sinus and maxillary teeth - inflammation of maxillary sinus can present with toothache
35
List the types of deafness
1. Conductive deafness
2. Sensorineural deafness
36
Describe the surgical treatment of otitis media with effusion
* Myringotomy - small incision in tympanic membrane, relieves pressure and allows for Grommet insertion
* Grommet - small tube inserted in tympanic membrane to ventilate middle ear and allow drainage of fluid
* Side effects - ear discharge (otorrhoea), tympanic membrane perforation
* Remain in membrane for 6 months - 2 years, spontaneously fall out
* Tympanic membrane usually closes without residual hole
37
Why is observation often the first line of management of otitis media with effusion? When is observation not appropriate?
* Spontaneous resolution is common
* Referral to ENT if:
* Severe hearing loss
* Delay in reaching developmental milestones
* Symptoms persist for longer than observation period
* Underlying craniofacial abnormality e.g. Down's syndrome/cleft palate
38
Where does the ethmoid sinus drain to?
* Anterior, middle and posterior
* Anterior drains to hiatus semilunaris
* Middle into ethmoid bulla
* Posterior into superior meatus
39
Describe the structure of the interior of the nasal cavity
* 3 nasal conchae - inferior, middle + superior
* 'Turbinates' - curved shelves of bone
* Create 4 pathways for air
* Inferior, middle and superior meatuses
* Spheno-ethmoidal recess
40
Define otitis media with effusion
* Also called serous otitis media/secretory otitis media/glue ear
* Fluid accummulation in the middle ear and mastoid air cells due to negative pressure produced by dysfunction of the auditory tube
* Can be associated with a viral or bacterial upper respiratory infection e.g. otitis media
* Causes conductive hearing loss
41
What is the function of the auditory tube?
Equalises pressure between the external environment and the middle ear
42
Describe the innervation of the muscles of the middle ear
* Tensor tympani - innervated by tensor tympani nerve (branch of mandibular nerve)
* Stapedius - innervated by nerve to stapedius (branch of facial nerve)
43
Describe the structure of the vocal folds
* Superor vestibular folds - false vocal folds
* Inferior vocal folds - true vocal folds
* Rima glottidis between the true vocal folds, size altered by muscles of phonation
44
What would be see during an otoscopy in otitis media with effusion?
* Dull tympanic membrane
* Loss of 'cone of light'
* Fluid level behind tympanic membrane
* Reduced tympanic membrane mobility
45
Where do the lacrimal ducts drain to?
Nasolacrimal duct drains to the inferior meatus
46
What is the clinical significance of the annular ligament?
Can calcify with age - common cause of deafness
47
List the parts of the external ear
1. Auricle/pinna
2. External acoustic meatus
3. Tympanic membrane
48
Why does motion sickness occur?
Sustained movement at constant velocity - endolymph keeps moving after movement stops
49
List causes of vestibular dysfunction and their symptoms/signs
* Due to labrythitis, vestibular neuritis, Meniere's disease etc.
* Symptoms/signs - vertigo, nausea, vomiting, loss of balance, nystagmus
50
What is the function of the tonsils?
* 1st line defence against ingested or inhaled foreign particles
* Engore with blood to assist in immune responses to common illnesses
* Have M cells (antigen presenting) on their surface, alert underlying B and T cells in the tonsil
* Hold B memory cells, allow for production of secretory antibodies (IgA)
* Produce T cells similarly to the thymus
51
Describe screening for deafness in children
* Newborns/first few weeks after birth - automated otoacoustic emission test (clicking noises, measure response)
* 8-12 months
* 4/5 years
* Further testing if hearing loss suspected
52
Why does cleaning the ear sometimes illicit an involuntary cough reflex?
Deep part of external acoustic meatus innervated by branches of the facial/vagus nerve - cleaning ears results in stimulation of the auricular branch of the vagus nerve which is responsible for controlling the cough reflex
53
Describe the appearance of a healthy tympanic membrane in an otoscopy
* Transluscent - can see middle ear structures through it
* 'Cone of light' - reflection of light during otoscopy
* Pearly grey colour
* Malleus and umbo visible
54
What is the clinical significance of the sphenoid sinus
Can reach the pituitary surgically through the sphenoid sinus and bone
55
What is the function of the auricle of the external ear?
Capture and direct sound towards the external acoustic meatus
56
Describe the impact of deafness on children
* Delayed speech and language development, communication, cognitive skills (learning)
* Linked to - isolation, low self-esteem, learning difficulties, behavioural problems
* Poor academic performance - often misidentified as ADD/ADHD, leads to frustration/confusion
* Early intervention is important
57
Where does the maxillary sinus drain to?
Drains into nasal cavity at hiatus semilunaris, under frontal sinus opening (potential spread of infection from frontal to maxillary sinus)
58
Where are the lingual tonsils located?
On posterior part of tongue base
59
Describe the clinical signs which would be seen in sensorineural deafness
* Rinne test positive - air conduction \> bone conduction
* Absolute bone conduction reduced
60
Describe the innervation of the intrinsic muscles of the larynx
* Inferior laryngeal nerve - terminal branch of the recurrent laryngeal nerve (branch of vagus nerve) except cricothyroid muscle
* Cricothyroid innervated by superior laryngeal nerve
61
Describe the lining and location of the nasopharynx
* Respiratory epithelium
* Ends at palatoglossal fold
62
How does the cribiform plate contribute to the nasal cavity?
Forms part of the roof of the nasal cavity, allows fibres of the olfactory nerve to enter/exit
63
List the gateways to the nasal cavity
1. Cribiform plate
2. Sphenopalatine foramen
3. Incisive canal
64
Why is caloric stimulation clinically relevant?
* Used to test brainstem integrity in unconscious patient (as well as pupil/gag reflex)
* Removal of ear wac by syringing may elicit reflex and cause dizziness
65
List the parts of the pharynx
1. Nasopharynx
2. Oropharynx
3. Laryngopharynx
66
Describe the signs/symptoms of otitis media with effusion
* Difficulty hearing - conductive hearing loss
* In young children often noticed as difficulty with attention at school or poor speech/language development
* Feeling of pressure inside ear
67
Describe the parts of the internal larynx
* Supraglottis - superior border of epiglottis to the vestibular folds
* Glottis - vocal folds and 1cm away
* Subglottis - inferior border of epiglottis to inferior cricoid cartilage
68
What kind of epithelium lines the paranasal sinuses?
Psuedostratified columnar ciliated epithelium (respiratory epithelium)
69
Describe the structure of the tonsils
* Mass of lymphoid follicles supported on a connective tissue framework
* Germinal centre - middle of nodules densely packed with lymphocytes
* Tonsillar crypts - penetrate from the surface, almost down to the centre of the tonsil follicle (except in pharyngeal tonsils)
* Luminal surface - non-keratinised stratified squamous epithelium (same as surrounding oropharynx)
* M cells on surface
70
Describe the location and function of the middle ear
Within the temporal bone, transmits vibration from the tympanic membrane to the inner ear
71
List the muscles of the middle ear and describe their function
* Protective function - contract in response to loud noises
* Tensor tympani - attaches to handle of malleus, pulls it off of tympanic membrane
* Stapedius - attaches to stapes
72
Describe the location of the pharyngeal recess
Also called fossa of Rosenmuller, deep pocket moving laterally from nasopharynx
73
What is the function of the conchae?
Increase the surface area of the nasal cavity to increase the amount of air in contact with the walls of the nasal cavity, make the airflow slow and turbulent
74
What is the clinical importance of the cricoid cartilage?
Pressure applied to occlude the oesophagus - prevents regurgitation of gastric contents.
= Cricoid pressure/Sellick's maneouvre
75
Where does the sphenoid sinus drain to?
Drains onto roof of nasal cavity
76
Describe the process of the vestibuloocular reflex
Rotation of the head, endolymph in semi-circular canals moves in opposite direction, causes activation of hair cells and eventual excitation of the extraocular muscles on one side with inhibition on the othe side
77
What is the tubal elevation?
* Elevation around opening of auditory tube
* Made of cartilage, lined by mucous membrane
* Rich in lymphoid tissue - tubal tonsil
* Projects 4/5mm into auditory tube
78
Define otitis media
Infection of the middle ear which causes inflammation and a build-up of fluid behind the tympanic membrane
79
Describe the location of the larynx and its anatomical relations
* C3-6, continuous with laryngopharynx superiorly and trachea inferiorly
* Covered anteriorly by infrahyoid muscles, laterally by lobes of thyroid
* Oesophagus is posterior
80
Describe the lining and location of the laryngopharynx
* Stratified squamous non-keratinised epithelium
* From tip of epiglottis to end of pharynx - where it narrows to become oesophagus (at level of C6)
81
Where are the cuneiform cartilages found?
In the aryepiglottic folds, strengthen the folds
82
Describe the general structure of the larynx
* Cartilaginous skeleton held together by ligaments and membranes
* Lined by pseudostratified ciliated columnar epithelium, except true vocal folds (stratified squamous epithelium)
83
Describe the aetiology of otitis media with effusion in adults
* Less common in adults than children
* Due to blockage of auditory tube - infection/occlusive mass
84
What is the clinical significance of the auditory tube?
* Path for upper respiratory infection to spread to middle ear
* Shorter and narrower in children, infection more common
85
Where does the auditory tube drain to?
Drains into the nasopharynx at the level of the inferior meatus, allows middle ear to equalise with atmospheric air pressure
86
What are tonsils?
* Collections of lymphoid tissue - sites of high immune activity
* Face into the aerodigestive tract, part of mucosa associated lymphoid tissue (MALT)
87
Describe the structure of the tympanic membrane
* 3 layers - outer cutaneous, middle fibrous and inner mucous membrane
* Cone shaped
* Handle of the malleus articulates with the tympanic membrane at the umbo
* Anterior and posterior malleolar folds move away from the lateral process of the malleus
* Thin, susceptible to perforation (trauma or infection)
88
Describe the structure of the arytenoid cartilage
* Pyramidal cartilages on top of the cricoid cartilage
* Attached to vocal cords - tighted/relax to change pitch of voice
* Attachment for posterior and lateral cricoarytenoid muscles
89
Compare the severity and treatment of conductive and sensorineural deafness
* Conductive - usually mild, treatable
* Sensorineural - usually persistance/long-lived, not treatable, can be mild, moderate, severe or profound
90
What is the clinical significance of the pharyngeal recess?
* Site of potential tumour growth
* Difficult to visualise - may have to take blind biopsy
* Passes close to internal carotid artery
91
List the tonsils which make up Waldeyer's ring of tonsil tissue
1. Pharyngeal tonsil
2. Tubal tonsil
3. Palatine tonsil
4. Lingual tonsil
92
Describe the structure of the external acoustic meatus
* Sigmoid shaped tube
* Extends from deep concha to the tympanic membrane
* Walls - external 1/3 = cartilage, internal 2/3 = tympanic part of temporal bone
93
Describe the structure and function of the ossicles of the middle ear
* Malleus, incus and stapes
* Held in place by ligaments - annular ligament of stapes
* Synovial joints between
* Amplify sound, transmit vibrations to inner ear
94
What causes conductive deafness?
* Blockage in outer or middle ear preventing conduction of sound into the inner ear
* Infection, impacted wax, perforated tympanic membrane, foreign objects
95
List the cartilages of the larynx
* Unpaired
* Thyroid
* Cricoid
* Epiglottis
* Paired
* Arytenoid
* Corniculate
* Cuneiform
96
What is the function of a Barany chair?
* Spins, used to test vestibuloocular reflex
* Observe nystagmus when spinning stops
* Head up - horizontal nystagmus/semi-circular canal
* Head down - rotational nystagmus, superior semi-circular canal
* Head down and turned 90 degrees - vertical nystagmus, posterior semi-circular canal
97
What is the Rinne test used for?
* Compares perception of sounds transmitter by air to those transmitted by bone conduction through the mastoid process
* Tuning fork against mastoid process then 1-2cm from auditory canal
* Normal or sensorineural deafness - air \> bone
* Abnormal (conductive deafness) - bone \> air
98
How is caloric stimulation used to test the vestibuloocular reflex?
* Injection of water into external acoustic meatus - higher or lower than body temperature
* Leads to heat transfer, convection current in horizontal semi-circular canal
* Fluid movement stimulates hair cells, activates vestibuloocular reflex
* Causes dizziness and horizontal nystagmus
99
Describe the structure of the epiglottis
Triangular flap of elastic cartilage at entrance of larynx, blocks entrance to larynx during swallowing - food bolus moves into oesophagus by passing through the piriform fossa on either side of the larynx
100
Where are the palatine tonsils found?
Between the palatoglossal arch anteriorly and palatopharyngeal arch posteriorly, in the isthmus of the fauces, laterally attached to wall by fibrous capsule
101
Describe the structure of the cricoid cartilage
* Complete ring of hyaline cartilage, inferior border of larynx (C6)
* United with trachea by cricotracheal ligament
102
Describe the structure of the thyroid cartilage
* Two laminae joined in the midline anteriorly to form the laryngeal prominence
* Posterior border project in superior and inferior horns
* Superior connects to hyoid bone via thyrohyoid ligament
* Inferior articulates with cricoid cartilage
103
How is the ear protected by structures in the external acoustic meatus?
* Hairs
* Secretion of the ceruminous glands
* Helps with lubrication and cleaning of the external acoustic meatus, protects from foreign objects and bacterial/fungal infections
104
Describe the innervation of the nasal cavity
* Special and general
* Special = olfactory nerve
* General
* Septal and lateral walls = nasopalatine nerve (branch of maxillary) and nasociliary nerve (branch of ophthalmic)
* External skin = trigeminal nerve
105
Where does the frontal sinus drain to?
Drains into nasal cavity via frontonasal duct, opens at hiatus semilunaris on lateral wall
106
Other than tonsils, what other structures are classified as MALT?
Peyer's patches in the gut
107
Describe the innervation of the lingual tonsil
Tonsillar branch of glossopharyngeal nerve
108
Describe the innervation of the palatine tonsil
Maxillary branch of trigeminal nerve, tonsillar branch of glossopharyngeal nerve
109
Describe the arterial supply of the palatine tonsils
* Ascending palatine branch of facial artery
* Tonsillar branch of facial artery
* Ascending pharyngeal branch of external carotid artery
* Dorsal lingual branch of lingual artery
* Lesser palatine branch of descending palatine artery
110
Which treatments are not usually recommended in the treatment of otitis media with effusion?
* Antibiotics
* Decongestants
* Corticosteroids
111
Describe the structure of the lingual tonsils
Covered by stratified squamous epithelium, single crypt
