Clinical Anatomy Of The Karynx Flashcards
What are the boundaries of the nasopharynx
Skull
Soft palate
Which part of the pharynx do the Eustachian tubes open into
Nasopharynx
4 Paranasal sinuses
Frontal
Ethmoidal
Maxillary
Sphenoid
Where do the paranasal sinuses drain to
Nasal cavity
What openings drain the paranasal sinuses
Ostia
Why is the maxillary sinus most at risk for infection
High up Ostia makes I hard to drain
Boundaries of the oropharynx
Soft palate
Epiglottis
Innervation to anterior 2/3 of tongue
General - lingual nerve
Special sensory - chorda tympani
Innervation of posterior 1/3 of tongue
Glossopharyngeal nerve
What is the lingual nerve a branch of
Mandibular nerve
What is the chorda tympani a branch of
Facial nerve
Boundaries of the laryngopharynx
Epiglottis
Oesophagus
Which part of the pharynx is continues opwith the eosophagus
Laryngopharynx
2 major functions of the larynx
Protects lower resp tract from aspiration of food
Vocal cords - sound production
How many cartilages in the larynx
9
Unpaired cartilages in the larynx
Thyroid
Epiglottis
Cricoid
Paired cartilages in the larynx
Arytenoid
Cuneiform - not important
Corniculate - not important
Is the hyoid bone above or below the cartilages of the larynx
Above
What vertebral level is the hyoid bone
C3
What vertebral levels does the larynx cover
C3-C7
Which cartilage forms the laryngeal prominence/ adams apple
Thyroid
Which cartilage do the vocal cords attach to anteriorly
Thyroid
What type of cartilage forms the epiglottis
Elastic
What shape is the epiglottis
Leaf
What does the epiglottis do during swallowing to prevent aspiration of food
Flattens and moves posteriorly to close off larynx
How many complete cartilaginous rings are present in the upper airway
1 - cricoid
Which cartilage forms the inferior border of the larynx
Cricoid
What structures does the cricoid cartilage articulate with
Inferior horns of Thyroid cartilage
Arytenoid cartilages
Cricothyroid membrane
What do the vocal cords attach to posteriorly
Arytenoids
What do the arytenoids sit on
Posterior aspect of cricoid cartilage
What is the function of the extrinsic laryngeal muscles
Allow larynx to move as a unit
Function of the intrinsic laryngeal muscles
Control and refine sound production
Where do extrinsic laryngeal muscles attach
Hyoid bone
Where do intrinsic laryngeal muscles attach
Vocal cords
2 groups of extrinsic laryngeal muscles
Suprahyoid
Infrahyoid
How many Suprahyoid muscles are there
4
How do the Suprahyoid muscles act on the hyoid bone and larynx
Elevate
What are the attachments of the Suprahyoid muscles
Skull
Hyoid bone
How many infrahyoid muscles are there
4
Where do the infrahyoid muscles attach
Pectoral girdle, sternum, thyroid cartilage
Hyoid bone
How do the infrahyoid muscles act on the hyoid bone and larynx
Depress
How many intrinsic laryngeal muscles are there
6 paired muscles
What alters the shape of the rima glottidis
Intrinsic laryngeal muscles
How do cricothyoid muscles affect the vocal cords and rima glottidis
Lengthens cords
Decreases aperture
Increase sound pitch
How do posterior cricoarytenoid muscles affect rima glottidis
Widens aperture for inhalation
How does lateral cricoarytenoid affect rima glottidis
Narrows aperture for whispering
How is sound produced in the larynx
Exhaled air builds up pressure below vocal folds -> expelled through rima glottidis -> vocal folds vibrate -> sound
Rima glottidis
Opening between vocal folds
What does the internal division of the superior laryngeal nerve supply
Mucosa above vocal cords
What does the external division of the superior laryngeal nerve supply
Cricothyroid
What nerve supplies the mucosa below the vocal cords
Recurrent laryngeal nerve
The recurrent laryngeal nerve supplies all intrinsic laryngeal muscles accept which
Cricothyroid
What structures do the right and left recurrent laryngeal nerves hook under
R - right subclavian artery
L - arch of aorta
Which nerve produces the gag reflex
Superior laryngeal nerve
What effects does a laryngeal nerve palsy cause
Reduced gag reflex
Reduced range of pitch
Effect of unilateral recurrent laryngeal nerve palsy
Hoarse voice
Which nerve palsy causes a hoarse voice
Unilateral recurrent laryngeal nerve
What does bilateral recurrent laryngeal nerve palsy cause
Loss of phonation
Difficulty breathing
Which arteries supply the larynx
Superior thyroid artery
Inferior thyroid artery
What vessel does the inferior thyroid artery branch of from
Thyrocervical rrunk
What vessel does the superior thyroid artery branch from
External carotid artery
Is the external or internal carotid artery more anterior
External
What does ‘some anatomists like freaking out poor medical students’ mean
Branches of carotid artery -
Superior thyroid
Ascending pharyngeal
Lingual
Facial
Occipital
Post auricular
Maxillary
Superficial temporal
What level is the laryngeal prominence
C4
Where does the carotid artery bifurcate
Superior border of thyroid cartilage - C4
What vertebral level is the cricoid cartilage
C6
What vertebral level is the thyroid gland
C6
What are the 2 options for an emergency airway
Surgical airway
Endotracheal tube
What does ABCDE stand for
Airway
Breathing
Circulation
Disability
Exposure
When does a patient need a definitive airway
Unable to maintain own airway
Risk of impending or potential airway compromise
Unable to maintain O2 levels with facemask
Presence of apnoea
Features of cerebral hypoperfusion
Suspected head injury / sustained seizure w risk of aspiration
How is a definitive airway set up
Tube placed in trachea with cuff inflated below vocal cords -> tube connected to oxygen enriched assisted ventilation -> airway secured with appropriate stabilising method
How can burns to the face or neck obstruct the airway
Direct tissue damage
Inhalation injury
Oedema and swelling from irritation from soot/debris
How can anaphylaxis obstruct the airway
Angioedema of lips, tongue, or larynx can block airway
How can face or neck trauma obstruct the airway
Laryngotracheal fracture - direct obstruction
Displacement of structures - secondary obstruction
Loose teeth, bone fragments - secondary obstruction
Post traumatic complications eg swelling, haematoma - secondary obstruction
When is a cricothyroidectomy performed
Emergency access to airway required
Unable to intubate
Where is a cricothyroidectomy performed
Cricothyroid membrane
How is a cricothyroidectomy performed
Cricothyroid membrane palpated -> incision made -> bougie inserted -> broncheostomy tube inserted
