Larynx Flashcards
Give 4 Functions of the Larynx
1) Sphincter for lower respiratory tract
2) Respiration
3) Mechanism for producing sound (phonation)
4) Swallowing Effort closure
Describe the stucture of the larynx
Hollow musculoligamentous structure with a cartilage framework that caps the lower respiratory tract
HIGHLY mobile!!
What is found above and below the larynx?
ABOVE: Superior laryngeal aperture opens into the laryngopharynx (just inferior to the tongue)
BELOW: Continuous with the trachea.
What is the motor and sensory innervation to the larynx?
CN X
What are the names of the 3 large unpaired cartilages of the larynx?
Cricoid, Thyroid and Epiglottis
What are the names of the 3 pairs of smaller cartilages of the larynx?
Arytenoid, Corniculate and Cuneiform
How are all of the cartilages connected?
By fibroelastic membrane and numerous intrinsic muscles
What is the anatomical name for the ‘adams apple’ and where is it located?
Laryngeal prominence located on the thyroid cartilage
What is the largest cartilage and describe its shape
Thyroid cartilage
Shield shaped, comprising two lamina. Has superior and inferior thyroid horns (hyoid and cricoid respectively)
What structure is ‘leaf shape’ and how it it attached to the thyroid cartilage?
Epiglottis- attached posteriorly to thyroid cartilage by thyroepiglottic ligament
What is the most inferior cartilage?
Describe its shape and the the purpose of its 2 articular facets on each side
Cricoid Cartilage
Signet ring shape and completely encircles the airway
Articular facets on each side with a:
- Superolateral surface for arytenoid cartilage
- Lateral surface for the medial surface of inferior horn of thyroid cartilage
What structure is indicated by the arrow?
State the function of this
Arytenoid Cartilage- pyramid shaped and contains a concave base articulating with cricoid
Involved in vocal cord movement
What 2 processes does Arytenoid cartilage contain and state their function
Label these on the image below
Vocal process: points forwards, for vocal cord attachment
Muscular process: points back and sideways, for attachment of intrinsic muscles… allows movement of the arytenoid depending on movement we want
What type of joints are the Arytenoid Cartilage
What is the clinical implication of this on RA patients
These are synovial joints and thus can be affect by RA, patient may present with voice problems
What are the mucosal depressions on either side of the larynx?
Piriform Recess (Fossa)
What is the function of the Piriform Recess?
Channels solids/liquids through the piriform fossae into oesophagus
During swallowing, how is the laryngeal inlet closed?
larynx moves up and forward → epiglottis swings downward toward arytenoid cartilages → closes the laryngeal inlet
What does the up and forward movement of the larynx cause during swallowing?
OPENING of the oesophagus, which is attached to the posterior aspect of the cricoid cartilage
What is indicated by the arrows?
Piriform Recess (Fossa)
Compare our ‘true’ vs ‘false’ vocal cords and label them on the image below
True → consist of vocal ligaments and elastic membrane that sits between ligaments and cricoid cartilage. Responsible for phonation
False → NOT responsible for sound and are located superior and lateral to the true cords (called the “Vestibular folds”)
Label the true vs false vocal cords AND the regions located above and below
Above: vestibule
Below: infraglottic space
The true vocal cords are oftens called the what?
The glottis
What are the 2 major blood supplies to the larynx? (incl what these are a branch of and structures it passes through)
Superior laryngeal arteries:
- Branch of the superior thyroid artery (first branch of ECA).
- Passes through a hole in the thyrohyoid membrane to supply the inside of the larynx
Inferior laryngeal arteries:
- Branch of the Inferior thyroid artery (from the thryocervical trunk)
Describe the 2 pathways for venous drainage of the larynx
Superior laryngeal vein ➞ superior thyroid vein ➞ Internal jugular vein
Inferior laryngeal vein ➞ inferior thyroid vein ➞ left brachiocephalic vein
Nerves of the larynx are all branches of what CN?
What are the 2 main nerves?
VAGUS nerve (CN X) gives of 2 branches to supply larynx:
- Superior Laryngeal Nerves
- Recurrent Laryngeal Nerves
Describe the pathway and structures innervated by the Superior laryngeal nerve
Descends medial to ICA on each side, then divides into Internal and External branches just above hyoid
Internal: Pierces Thyrohyoid membrane and provides sensory innervation of the internal larynx until the level of vocal folds
External: Innervates Inferior Constrictor muscle (pharynx) + Cricothyroid muscle
What sensory and motor innervation do the Recurrent Laryngeal Nerves provide?
Provides sensory innervation to laryngeal cavity BELOW the level of vocal folds and Motor to ALL intrinsic muscles of larynx (EXCEPT Cricothyroid)
List 2 things that are unique to the Cricothyroid
1) Only intrinsic muscle of the larynx which is NOT innervated by the recurrent laryngeal nerve (its supply is from the External branch of the Superior Laryngeal Nerve)
2) ONLY tensor muscle of the larynx to ELONGATE the vocal cords (stretch them tight) → Important for forceful speech/ changing pitch
Describe the pathway of the Right vs Left recurrent laryngeal nerves
Right – hooks under right subclavian artery
Left – hooks under aortic arch
The Tracheo-oesophageal groove is useful in identifying what?
Right recurrent laryngeal nerve
What is the function of the Cricothyroid Muscle?
Important for forceful/loud speech and changing pitch
State the Intrinsic Muscles of the Larynx and the function of each
Cricothyroid muscles- elongates vocal cords (tensor)
Thyroarytenoid (‘vocalis muscle’)- shortens vocal cord (relaxor)
Lateral cricoarytenoid muscles (AD-duct)
Transverse and oblique arytenoid muscles (AD-duct)
Posterior cricoarytenoid muscles (AB-duct)
State the movement and the muscles of the vocal cords involved in:
- Forceful speech/changing pitch
- Deep inspiration/breathing
- Speaking
- Sphincter/swallowing (to stop food entry into larynx)
- Soft speech
1) Forceful speech/changing pitch ➞ elongation of cords ➞ cricothyroid
2) Deep inspiration/breathing ➞ ABduction (opening cords) ➞ Posterior cricoarytenoid
3) Speaking ➞ ADDuction (folds together) ➞ lateral cricoarytenoid and transverse and oblique arytenoid
4) Sphincter/ swallowing ➞ ADDuction ➞ lateral cricoarytenoid and transverse and oblique arytenoid
5) Soft speech ➞ shortening of cords ➞ Thyroaryntenoid
Give the 4 layers of vocal cords
- Stratified squamous epithelium
- Reinke’s space
- Vocal ligament
- Vocalis muscle
What is the name of the potential space located in the vocal cords and why is it important?
Reinke’s space- important role in the vibration of the vocal cords
Label the intrinsic muscles of the larynx and state which one cannot be seen in this image
We cannot see the Cricothyroid (elongation)
What muscle is shown on this image?
Cricothyroid!!
State which image shows the vocal cords during:
- breathing
- phonation
- increase in abdominal pressure/ effort closure
- deep inspiration
Label the vocal cord and state what this position most likley indicates
Describe the position of this vocal cord and state what this most likley indicates
Label and describe the position of this vocal cord
State what this position most likley indicates
Describe the vocal cord and state what this position most likley indicates
State what this position most likley indicates
Where would you perform a Tracheostomy?
Along the cricothyroid ligament ➞ gap between the cricoid layngeal prominence and arch of cricoid cartilage
State the clinical importance of the cricothyroid ligament
This is the location you make an incision during a cricothyroidotomy (cricothyrotomy) for emergency airway access
In what direction does the larynx open and into what structure?
Opesn BACKWARDS into the laryngopharynx
What suspends the larynx and how it it attached to the trachea?
Suspended from the hyoid bone above and attached to the trachea below by membranes and ligaments
