LARYNX Flashcards
location of larynx?
anteiror compartment of the neck
suspended from hyoid bone, opens superiorly in laryngopharynx, spans C3-C6 and then continues inferiorly with the trachea
boundaries of the larynx?
covered anteriroly by the infrahydois muscles, laterally by the thyroid lobes and posteriorly by oesophags
what is the internal cavity of the larynx lined by?
pseudostratified columnar epithelium
(other than true vocal cords which are lined by stratified squamous epithelium)
what are the 3 regions of the larynx?
supraglottis - from inferior epiglottis to vestibular folds
glottis
subglottis - from 1cm bellow glottis to inferior border of cricoid cartilage
vasculature of the larynx?
arterial - superior and inferior laryngeal arteries
venous - superior and inferior laryngeal veins
sensory and motor inervation to the larynx?
recurrent larngeal nerve provides motor innervation to all internal muscles except the cricothyroid + sensory innervation to infraglottis
superior laryngeal internal branch provides sensory innervation to supraglottis, and external branch provides motor innervation to the cricothyroud muscles
infrahyoid muscles?
omohyoid
sternohyoid
sternothyroid
thyrohyoid
suprahyoid muscles?
stylohyoid
digastric muscle
mylohyoid
gleniohyoid
how can we visualise the larynx?
laryngoscopy or videostroboscopy
what is videostroboscopy?
using an endoscope with a strobe light to create a series of images that appear to be slow motion vibration of the vocal folds. This helps assess how well the vocal cords are vibrating
physiology of vocal cord vibration?
intrinsic muscles bring vocal cords together to close the glottis
pressure against the closed vocal cords blows them apart
When the vocal folds vibrate, they alternately trap air and release it. Each release sends a little puff of air into the pharynx; each puff of air is the beginning of a sound wave
Physiology of vocal cords to raise the pitch?
Vocal cords vibrate faster so they get thinner by being stretched - done by extrinsic laryngeal muscles
What is laryngitis?
Inflammation or infection of the larynx and vocal cords
Most common causes of laryngitis?
Viral laryngitis is most common - rhinovirus, adenovirus, parainfluenza, influenza
Bacterial and fungal also possible
Can also be caused by trauma e.g. excessive voice use, chronic coughing etc
Symptoms of laryngitis?
Episodic coughing
Throat clearing behaviours
Hoarse voice
Dysphonia
Dysphagia
Fever
Systemic symptoms
Management of laryngitis?
Self-limiting so offer NSAIDs
When should you offer antibiotics for a sore throat?
Marked systemic upset
Unilateral features of peritonsillitis
PMHx of rheumatic fever
an increased risk from acute infection (such as a child with diabetes mellitus or immunodeficiency)
patients with acute sore throat/acute pharyngitis/acute tonsillitis when 3 or more Centor criteria are present
What antibiotics should be given for a sore throat if indicated?
Phenoxymethylpenicillin for 7-10 days
(Clarithromycin if allergic)
What is the centor criteria?
Centor criteria: score 1 point for each (maximum score of 4).
Tonsillar exudate.
Tender anterior cervical lymphadenopathy or lymphadenitis.
History of fever (over 38°C).
Absence of cough.
A score of 0, 1 or 2 is thought to be associated with a 3-17% likelihood of isolating streptococcus. A score of 3 or 4 is thought to be associated with a 32-56% likelihood of isolating streptococcus.
What is the FeverPAIN criteria?
Score 1 point for each (maximum score of 5)
Fever (during previous 24 hours).
Purulence (pharyngeal/tonsillar exudate).
Attend rapidly (within 3 days after onset of symptoms).
Inflamed tonsils.
No cough or coryza.
A score of 0 or 1 is associated with a 13-18% likelihood of isolating streptococcus. A score of 2 or 3 is associated with a 34-40% likelihood of isolating streptococcus. A score of 4 or 5 is associated with a 62-65% likelihood of isolating streptococcus.
What most commonly causes acute sore throats?
Viruses - most commonly rhinovirus, coronavirus, parainfluenza virus, influenza virus
Strep, adenovirus, HSV 1, EBV, fusobacterium necrophorum
Whats the most common bacterial case of sore throat?
Group A beta-haemolytic strep (strep pyogenes)
What is scarlet fever?
A reaction to erythrogenic toxins produced by group A haemolytic strep (usually strep pyogenes)
Spread via resp route
Most common in children 2-6
Presentation of scarlet fever?
Fever for 24-48 hours
Malaise, headache
N&v
Sore throat
Strawberry tongue
Pinhead rash on torso most obvious in flexure with a rough sandpaper texture (desquamation occurs later around fingers & toes)
Compilations of strep pharyngitis/tonsilitis?
Scarlet fever
Otitis media
Acute sinusitis
Quinsy
More rare…
Acute rheumatic fever
Acute glomerulonephritis
Reactive arthritis
What is a quinsy?
A peritonsillar abscess that usually develops as a complication of bacterial tonsillitis
Presentation of a quinsy?
Severe throat pain lateralising to 1 side
Deviation of uvula to unaffected side
Trismus (difficulty opening mouth)
Reduced neck mobility
Management of quinsy?
Urgent ENT review
Needle aspiration or incision and drainage
IV antibiotics
Consider tonsillectomy for prophylaxis
Examination findings for pharyngitis?
Pharyngeal exudate
Cervical lymphadenopathy
Fever
Examination findings for tonsilitis?
Tonsillar exudate
Enlargement and erythema of tonsils
Anterior cervical lymphadenopathy
Fever
What symptoms suggest viral rather than bacterial pharyngitis?
Rhinorrhoea
Nasal congestion
Cough
What symptoms suggest a strep infection of the throat?
Fever over 38.5
Exudate on pharynx or tonsils
Anterior neck lymphadenopathy
Absence of cough
What causes glandular fever?
EBV (HHV-4)
Classic triad of symptoms for glandular fever?
2-4 weeks of…
Sore throat
Lymphadenopathy
Pyrexia
(May also cause malaise, anorexia, headache, palatal petechia, splenomegaly, hepatitis, haemolytic anaemia, lymphocytosis)