18 - The Larynx Flashcards Preview

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Flashcards in 18 - The Larynx Deck (30)
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1
Q

Where is the larynx found and what are it’s functions?

A
  • Between the hyoid bone (laryngeal inlet) and the end of the cricoid cartilage at C6
  • Ventilation
  • Airway protection from food and fluid
  • Cough reflex
  • Phonation
2
Q

What are the three divisions of the larynx?

A
3
Q

Where are the two synovial joints in the larynx?

A
  • Between the arytenoid cartilage and cricoid
  • Between thyroid and cricoid cartilage
4
Q

Label the different parts of the larynx.

A
5
Q

What is a cricothyroidotomy?

A
  • In acute laryngral obstruction, e.g due to tongue swelling or laryngospasm, the cricothyroid membrane can be punctured to get below the vocal areas
  • Used when cannot intubate or ventilate and temporary solution to hypoxic damage being caused to brain and tissues
6
Q

Label the following parts of the larynx.

A
  • Aryepiglottic folds are the upper part of the quadrangular membrane
  • Aditus = laryngeal inlet
7
Q

Where do the vocal ligaments (cords) form from?

A
8
Q

What is the structure of the thyroid, cricoid and arytenoid cartilages?

A
  • Thyroid: shield like. two lateral plates that meet in the middle to form a laryngeal prominence

- Cricoid: only complete ring of cartilage. Attached to trachea by cricotracheal membrane

- Artyenoid: sit on posterior cricoid

9
Q

What is the rima glottis?

A
  • Space between the vocal cord, yellow star on the diagram
  • Subglottis is true vocal cords to first tracheal ring
10
Q

What type of epithelium lines the larynx?

A

All pseudostratified columnar apart from the true vocal cords that are lined with stratified squamous

11
Q

Label the following view down the laryngoscope?

A

Can put down ET tube with small balloon past abducted vocal cords

12
Q

What procedure might you carry out if someone has a change in voice that becomes hoarse?

A
13
Q

What are the functions of the intrinsic laryngeal muscles and what nerve are they supplied by?

A
  • Open glottis and vocal cords in inspiration
  • Phonation and cough refelx
  • Close cords and glottis when swallowing

All recurrent laryngeal from vagus, apart from cricothyroid that comes from superior laryngeal

14
Q

What is the only intrinsic muscle of the larynx that abducts the vocal cords, and how does it work?

A

Posterior cricoarytenoid

Moves the arytenoids position on cricoid to change the aperture (rima glottidis)

15
Q

How do the vocal cords look when speaking and coughing?

A

Coughing: inspire and fill lungs with air, adduct cords, contract expiratory muscles, abduct cords

If recurrent laryngeal nerve damage then phonation and cough will be affected

16
Q

What is the function of the cricothyroid muscle?

A

It stretches the vocal cords making them taut, allowing high-pitched sounds to be made

Supplied by external branch of superior laryngeal

17
Q

How does the larynx change during swallowing to protect the airways?

A
  • Tongue pushes the epiglottis down along with aryepiglottic muscles contracting
  • Vocal cords (glottis) adduct
  • Larynx moves anterior to pull off pharynx and moves upwards as hyoid moves upwards
18
Q

What is the sensory and motor function of the larynx?

A

Autonomics delivered via CN X to mucosal glands within the larynx

19
Q

What happens if there is a lesion to the superior laryngeal nerve?

A
  • Often damage external branch when thyroidectomy as associated with superior thyroid artery
  • Cricothyroid will be paralysed so hoarseness or issue making high pitched noises
20
Q

What is the course of the recurrent laryngeal nerve, and how can it be injured?

A
  • Comes from vagus nerve and associated with thyroid and inferior thyroid arteries
  • Sensory to all areas below vocal cords and all motor apart from cricothyroid

- Injury: thyroid surgery, aortic arch aneurysm, cancer of apex of the lung, larynx/oesophagus surgery

21
Q

How does a recurrent laryngeal nerve palsy present?

A
  • Hoarseness of voice and ineffective cough
  • Unilateral lesion then vocal cord in paramedian position on affected side between adduction and abduction
  • If bilateral then there is a narrow glottis and this is an emergency as really narrow airway
22
Q

What are some conditions that affect the larynx and how do they present?

A

Most present with hoarse voice

  • Laryngitis
  • Singer’s nodules
23
Q

What is the innervation of the infrahyoid muscles?

A
  • Branches of C1 to C3 from the cervical plexus
  • Move and stabilise the hyoid bone during speaking, swallowing, chewing
24
Q

What is the prognosis for carcinomas in different parts of the larynx?

A

Glottis: if caught early good prognosis as minimal lymphatic drainage so less likely to spread

Infra/Supraglottis: drain to neck and paratracheal nodes so poorer prognosis

25
Q

Which recurrent laryngeal nerve is more at risk of being damaged?

A

Left as goes under the arch of the aorta and back up a groove between the oesophagus and trachea

26
Q

What is the presenting symptoms of epiglottitis, what is it caused by and how do you treat it?

A
  • Inflammation of the epiglottis, usually due to H.Influenzae B but rare as Hib vaccine
  • Usually in children 2-6, stridor, difficulty breathing, difficulty swallowing so may dribble, high fever, sore throat, sitting up in ‘sniffing’ position
  • Do not examine as epiglottis may snap shut, refer to ENT and intubate or do a tracheostomy
27
Q

What is croup caused by and what are the presenting symptoms?

A
  • Usually viral, parainfluenza virus, affecting larynx and trachea
  • Common in 6 months to 3 years
  • Barking cough made worse on agitation and at night
  • Stridor can also occur when upset and cyanosis
28
Q

How can we treat croup?

A
  • Can often be dealt with at home by giving single dose corticosteroid, calming them down and sitting them up
  • If respiratory distress or stridor at rest can give nebulised oxygen and adrenaline with corticosteroids
29
Q

Why can a hoarse voice be a red flag?

A

Could be a sign of laryngeal, lung or thyroid cancer

30
Q

What is the vallecula?

A
  • Recess between root of the tongue and the epiglottis
  • When using laryngoscope can put blade in vallecula and push the tongue foward, lifting the epiglottis making it easier to view vocal cords