Applied anatomy of the larynx Flashcards
All paranasal sinuses drain into nasal cavity via openings called ‘[]’
All paranasal sinuses drain into nasal cavity via openings called ‘ostia’
Label the nerves that supply general sensation and tase in the anterior 2/3rd of the tongue [2]
A: Lingual nerve - mandibular nerve (CN V3)
B: Chorda tympani: Facial Nerve (CNVII)
Which nerve provides general sensation and tase to the posterior 1/3rd of the tongue? [1]
Glossopharyngeal nerve (CN IX)
what are the nasal conchae?
aka?
covered in ?
function?
- *nasal conchae:**
- *-** curved folds of bone
- aka nasal turbinates
- covered in ciliated resp. epithelium (aka pseudostratified columnar)
- curve in medially and laterally
- function: rapid warming and humidification of air as it passes to the lungs.
- The superior and middle nasal conchae & inferior nasal conchae are made from which bone?
- why does your nose run when you cry?
Superior and middle nasal conchae are from the ethmoid bone
The inferior nasal conchae is its own bone
nose runs when you cry:
- nasolacrimal duct (the tear duct) drains into the inferior meatus,
- Tear duct from our eye empties next to our inferior conchae, so drainage of this naso-lacrimal duct is what makes the nose run*
which bone is the cribiform plate in?
cribiform plate in the ethmoid bone
what are the paranasal sinuses?
how many are there / what are they called?
what is their function (3) ?
paranasal sinuses: air filled spaces within the facial skeleton, continous with nasal cavity
4 paired sinuses: frontal, ethmoid, sphenoidal and maxillary
- *funtion:**
- *-** humidify air
- reduce weight of skull
- lined with resp. pseudostratified columnar epitheloium with cilia: immunological defence
what connects the middle ear to the nasopharnyx?
what is the role of ^? (2)
eustachain tube
function:
- equalises pressure
- drains mucous from middle ear
also infection can spread between middle ear and nasopharynx
what is the name for blockage of the eustachian tube ?
what does this cause?
who is it more common in?
otitis media - causes build up of mucous / fluid. can be due to inflammation or infection
common in younger children (ET is more horizontal so gets blocked easier)
what are the nasopharynx, oropharynx and laryngopharynx innervated by?
nasopharynx: CN V2
oropharynx: CN IX
laryngopharynx: CN X
how many cartilages are there in the larynx?
which are the paired (3)
which are the unpaired? (3)
- 9 cartilages
- three unpaired cartilages: epiglottis, thyroid and cricoid cartilage
- three paired cartilages: arytenoid, corniculate and cuneiform
which part of larynx is the adams apple?
which part of larynx is the only complete ring of cartilage?
thyroid cartilage = adams apple
complete ring of cartilage: cricoid cartilage (signet ring)
what happens to the epiglottis when you swallow?
larynx moves up, towards base of tongue and hyoid bone: makes the epiglottis close over the laryngeal inlet to prevent aspiration into trachea
which ligament connect the hyoid bone and thyroid? - what is this covered by?
which ligament connects the cricoid and thyroid cartilage?
where does ithe internal laryngeal nerve and superior laryngeal artery enter larnyx?
Hyoid bone and thyroid are joined by thyrohyoid ligament, covered by a thyrohyoid membrane.
Internal laryngeal nerve and superior laryngeal artery come through this ligament/membrane
Between the cricoid and thyroid cartilages: Crico-thyroid ligament
- The trickiest is the omohyoid (as it is not named according to a location) yet it is key to remember it has two bellies like the digastric. It is a long muscle with a white tendon in the middle
- Sterno-hyoid muscle goes all the way from the sternum to the hyoid
- Sterno-thyroid goes from the sternum from the sternum to the thyroid
- Thyro-hyoid goes from the thyroid to the hyoid
Sterno-hyoid goes the whole length, sterno-thyroid is halfway up and thyro-hyoid above it.
which muscle is this?
omohyoid
what is cricothyroidotomy?
cricothyroidotomy: is a procedure that involves placing a tube through an incision in the cricothyroid membrane (CTM) to establish an airway for oxygenation and ventilation
Vestibular Folds – Mucous membranes encasing vestibular ligaments. Protective function.
Rima Vestibuli – Space between vestibular ligaments
Vocal Folds (Vocal Cords) – Mucous membranes encasing vocal ligaments
Rima Glottidis - Space between vocal ligaments
Glottis – Vocal apparatus of larynx including vocal folds, ligaments and Rima Glottidis
what is the glottis?
Glottis: Vocal apparatus of larynx including vocal folds, ligaments and Rima Glottidis
what is general function of intrinsic muscles of larynx? (3)
which is the main cartilage that move for phonation?
which intrinisc muscle is not involved in movement of cartialge to produce phonation?
- cough
- phonation
- pitch of voice
The main cartilages that move for phonation are the arytenoid cartilages
All of the intrinsic muscles, other than the cricothyroid, are involved in movement of cartilage to produce phonation.
what is the rima glottidis?
rima glottidis: space between vocal ligaments
what happens to the rima glottis during:
- normal respiration?
- forced respiration?
- phonation?
- normal respiration: narrow wedge shape
- forced respiration: wide triangle shape
- phonation: the vocal cords close and the glottis is slit-like, if apparent at all
- whispering: achieved by leaving part of the rima glottidis open throughout the production of the sound.
which nerve controls most of the muscles of larynx? - which muscle does it not innervate?
most motor to muscles controlled by the recurrent laryngeal nerve - PHONATION
sensory innervation to area below vocal cords
doesnt innervate motor control for cricothyroid (comes from superior laryngeal nerve)
what can happen to nerves during thyroid surgery?
Could be caused by surgery to the neck (particularly thyroid), Tumours (often thyroid) leading to compressing nerve, trauma or viral infection, thyroidectomy due to tumour/hyperthyroidism.
Recurrent laryngeal injury will result in paralysis of all intrinsic muscles except cricothyroid which will cause problems with phonation. Vocal cord paralysis means you will be unable to abduct laterally, leading to hoarseness (if this damage only occurs on one side) or aphonia (if the damage is bilateral).
Stridor or respiratory distress can happen if acute due to blockage of the airflow which your body is not able to adapt to. This is due to paralysis of intrinsic muscles.
External laryngeal will lead to paralysis of cricothyroid preventing higher pitched phonation. This leads to Weak voice with low pitch, reduced range so your voice easily tires
What are the 2 major functions of the larnyx? [2]
- Protects the lower respiratory tract from aspiration of food
- Contains vocal cords – allows production of sound
Name the 3 unpaired cartilages
Name the 1 paired cartilage you need to know
Unpaired:
- Thyroid cartilage
- Epiglottis
- Cricoid cartilage
Paired:
- Artyenoid cartilages
The larynx lies in which vertebral layers? [1]
C3-C6
The vocal cords attach anteriorly to which cartilage?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
The vocal cords attach anteriorly to which cartilage?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
During swallowing, epiglottis [] and moves [] to close off the larynx
During swallowing, epiglottis flattens and moves posteriorly to close off the larynx to prevent aspiration of food
Which of the following is the only complete cartilaginous ring within the upper airway?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
Which of the following is the only complete cartilaginous ring within the upper airway?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
What does the cricoid cartilage attach to:
Anteriorly?
Posteriorly?
Anteriorly: Cricothyroid membrane
Posteriorly: Inferior horns of thyroid cartilage + paired arytenoid cartilages
The vocal cords attach anteriorly to which of the following?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
The vocal cords attach anteriorly to which of the following?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilages
Thyroid cartilage
The vocal cords attach anteriorly to which of the following?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
The vocal cords attach anteriorly to which of the following?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilages
Thyroid cartilage
Label A-D
Extrinsic larryngeal muscles:
- Attach to which bone?
- Act on which surface of the larynx?
- Role?
Intrinsic laryngeal muscles:
- Attach to which structure?
- Role?
Extrinsic larryngeal muscles:
- Attach to which bone: hyoid bone
- Act on external surface of the larynx
- Role: allow larynx to move as a unit
Intrinsic laryngeal muscles:
- Attach to vocal cords structure
- Role: Control and refine sound production
How can you subclassify the extrinsic muscles? [2]
Suprahyoid muscles
Infrahyoid muscles
What is the role of the four (extrinsic) suprahyoid muscles? [1]
What is the role of the four (extrinsic) infrahyoid muscles? [1]
Suprahyoid: Elevate the hyoid bone & larynx (e.g during swallowing)
Infrahyoid: Depress the hyoid bone
Explain MoA of sound production
- Exhaled air from trachea, builds up pressure below the vocal folds.
- Air is expelled through the opening between vocal folds (Rima Glottidis)
- As air travels through the Rima Glottidis it causes the vocal folds to oscillate/vibrate
- Vibration of the vocal cords generates sound
- The length, size and tension of the vocal folds affects the pitch and volume of sound
- The intrinsic laryngeal muscles form part of the vocal fold and refine sound production by changing the shape and tension of the vocal cords
*
How can you think about the intrinsisc laryngeal muscles? [2]
Cricothyroid
All others
What is the sensory innervation to all muscles below the vocal cords? [1]
What is the sensory innervation to all muscles above the vocal cords? [1]
What is the motor innervation to all muscles of the larynx except for the cricothryroid? [1]
What is the motor innervation to all muscles of the larynx except for the cricothryroid? [1]
What is the sensory innervation to all muscles below the vocal cords? [1]
Recurrent laryngeal nerve
What is the sensory innervation to all muscles above the vocal cords? [1]
Internal laryngeal nerve
What is the motor innervation to all muscles of the larynx except for the cricothryroid? [1]
Recurrent laryngeal nerve
What is the motor innervation to all muscles of the larynx except for the cricothryroid? [1]
External laryngeal nerve
Which nerve is responsible for the opening the rima glottidis to refine sounds during phonation? [1]
Recurrent laryngeal nerve
Palsy to which nerve causes loss of phonation?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
Palsy to which nerve causes loss of phonation?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
What are the effects of superior, internal and external branch palsies? [A&B]
A: reduced gag reflex
B: reduced range of pitch
Palsy to which nerve causes reduced gag reflex?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
Palsy to which nerve causes reduced gag reflex?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve
Palsy to which nerve causes reduced range of pitch?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
Palsy to which nerve causes reduced range of pitch?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
Palsy to which nerve causes horseness of voice?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
Palsy to which nerve causes horseness of voice?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
