The larynx is enclosed within which fascia?
Which structures can be found within the pretracheal fascia?
- Strap muscles
- Thyroid gland
- Trachea and larynx
- Oesophagus and pharynx
- Recurrent laryngeal nerves
The larynx is found anteriorly to which structure?
Which vertebral levels can the larynx be found?
C4 and C6
What are the main fuctions of the larynx?
- Keeps upper respiratory tract patent
- Prevents entry of foreign bodies into lower respiratory tract
- Vocal cords produce sound
Which muscles can be classed as strap muscles?
- Levator muscle of the thyroid gland
What are the three processes of the arytenoid cartilages?
What are the false vocal cords?
Thick folds of mucosa surrounding the vestibular ligaments which connect the arytenoid cartilages to the epiglottis
What are the true vocal cords?
Thick folds of mucosa encompassing the vocal ligament which travels between the vocal process of the arytenoid cartilage to the thyroid cartilage
Which membrane can be found between the vestibular ligament and epiglottis?
Name the five different types of intrinsic muscles in the larynx?
- Cricothyroid muscles
- Thyroarytenoid muscles
- Lateral crico-arytenoid muscles
- Arytenoid muscles
- Posterior crico-arytenoid muscles
What innervates the intrinsic muscles of the larynx?
(Inferior (recurrent) laryngeal nerve innates all except the cricothyroid which is innervated by the superior laryngeal branch of the vagus nerve)
What is the function of the cricothyroid muscles?
Tenses vocal ligament
(increases pitch of voice)
What are the attachments of the cricothyroid muscles?
Anterolateral cricoid cartilage
Inferior horn of thyroid cartilage
What is the function of the thyroarythenoid muscles?
Relax vocal ligament
(lowers pitch of voice)
What are the attachments of the thyroarytenoid muscles?
Anterior arytenoid cartilage
What is the function of the lateral crico-arytenoid muscles?
Adducts vocal ligaments
What are the attachments of the lateral crico-arytenoid muscles?
Muscular process of the arytenoid
Anterior cricoid cartilage
What is the function of the arytenoid muscles?
Adducts vocal ligaments
(makes voice quieter)
What are the attachments of the arytenoid muscles?
One arytenoid cartilage to the opposite cricoid cartilage
What is the function of the posterior crico-arytenoid muscles?
Abducts vocal cords
(makes voice louder)
What are the attachments of the posterior crico-arytenoid muscles?
Posterior cricoid cartilage
Muscular process of arytenoid cartilage
Where do supra-glottic tumours spread?
Superior deep cervical lymph nodes
Where do glottic tumours spread?
95% stay of the cords
Where do sub-glottic tumours spread?
Which cranial nerves are involved in speech?
CN V3 - Tension of soft palate
CN X - Elevation of soft palate
CN XII - Tongue movement
CN VII - Movement of teeth and lips
What is the innervation of the mucosa
a) Above the vocal folds
b) Below the vocal folds
a) Internal laryngeal nerve - Above the vocal folds
b) Inferior laryngeal nerve - Below the vocal folds
What are the branches of the superior laryngeal nerve?
- Internal laryngeal nerve
- External larngeal nerve
At which point does the recurrent laryngeal nerve become the inferior laryngeal nerve?
Locel of the cricothyroid joint
How can the vagus nerve and its branches be clinically tested?