Head And Neck Session 11 Flashcards
What are the cartilaginous components of the larynx?
3 singular: thyroid, cricoid and epiglottic
3 paired: arytenoid, corniculate and cuneiform
Which vertebral levels is the larynx located at?
C3-6
Which bone is part of the larynx?
Hyoid
What are the functions of the larynx?
Respiration, phonation, protection of trachea and bronchial tree during swallowing, cough reflex
What covers the anterior aspect of the larynx?
Infrahyoid muscles
What is found lateral to the larynx?
Loves of thyroid and major BV of neck
What lines the larynx?
Ciliated columnar epithelium
Where is the supraglottis?
Inferior surface of epiglottis to vestibular folds
What is the alternative name for the vestibular folds?
False vocal cords
Where is the vallecula?
Between tongue base and epiglottis
Where is the glottis?
From the vocal cords to 1cm inferiorly
What is between the supraglottis and glottis?
Transglottic space
What is the subglottis?
1cm inferior to the vocal cords to border of cricoid cartilage
What does the superior margin of the quadrangular membrane form?
Aryepiglottic fold
What are the layers of the vocal cord?
Stratified squamous epithelium, Reinke’s space, vocal ligament, vocalis muscle
What are the components of the vestibular fold that runs from the thyroid to the arytenoid?
Ventricular ligament and loose mucosa
What is the function of Reinke’s space?
Allow free vibration of the epithelium
What does Reinke’s space contain?
Watery, amorphous substance
What forms the sub-mucosal fibroelastic membrane of the larynx?
Quadrangular membrane and conus elasticus
What forms Adam’s apple?
Laryngeal prominence of thyroid cartilage
What attaches to the lateral thyroid ligaments?
Thyrohyoid membrane
What does the superior horn of the thyroid cartilage articulate with?
Hyoid bone
Which nerves pierce the thyrohyoid membrane?
Superior and internal laryngeal nerves
What does the inferior horn of the thyroid cartilage articulate with?
Cricoid cartilage
What does the rotation and gliding movement of the cricoid at the inferior horn of the thyroid cartilage allow?
Change in vocal fold length
What is the cricoarytenoid joint?
Base of arytenoid and superolateral cricoid
What movements does the cricoarytenoid joint facilitate?
Slide, tilt and rotate
What action does the cricoarytenoid joint have on the vocal folds?
Approximate, tense and relax
What shape is the cricoid cartilage?
Signet ring
Which ligaments attach to the cricoid cartilage?
Median cricothyroid and cricotracheal
What are the two facets on the cricoid cartilage for?
Articulation with arytenoid cartilage and inferior horn of thyroid cartilage
Which muscles attach to the muscular process of the arytenoid cartilage?
Posterior and lateral cricoarytenoid muscle
What is the articular facet of the arytenoid cartilage for?
Corniculate cartilage
What does the apex of the arytenoid cartilage bear?
Corniculate cartilage
What does the vocal process of the arytenoid cartilage attach to?
Vocal ligament
Which two cartilages are found in the aryepiglottic fold?
Corniculate and cuneiform
Which cartilage found in the larynx does not attach to any other cartilages?
Cuneiform
What provides arterial supply to the larynx?
Superior and inferior laryngeal arteries
What arteries do those supplying the larynx branch from?
Superior and inferior thyroid
Which nerve follows the superior laryngeal artery?
Superior laryngeal nerve
Which nerve follows the inferior laryngeal artery?
Internal laryngeal nerve
Where does the superior laryngeal vein drain?
Into superior thyroid to IJV
Where does the inferior laryngeal vein drain?
Inferior thyroid or into venous plexus on trachea to L brachiocephalic vein
Describe the lymphatic drainage of the larynx.
Superior to vocal folds: with superior laryngeal artery to superior deep cervical nodes.
Inferior to vocal folds: pretracheal and paratracheal nodes to inferior deep cervical nodes
Which are the extrinsic muscles of the larynx?
Suprahyoids, infrahyoids and stylopharyngeus
Which are the intrinsic muscles of the larynx?
Cricothyroid, thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, transverse and oblique cricoarytenoids
What is the action of cricothyroid?
Stretch and tense vocal cords
What is the action of thyroarytenoid?
Relax vocal cords
What is the function of posterior cricoarytenoid?
Abduct vocal folds
What is the action of lateral cricoarytenoid?
Addict vocal folds
What is the common function of transverse and oblique cricoarytenoids?
Adduct arytenoid cartilages
Describe the innervation of the intrinsic laryngeal muscles.
All internal laryngeal nerve except cricothyroid that is external laryngeal nerve
Which structure of the neck does the superior laryngeal nerve travel in?
Carotid sheath
What innervation does the internal laryngeal nerve supply?
Sensory and autonomic to supraglottis
What are the two branches of the superior laryngeal nerve?
Internal and external
What innervation does the external laryngeal nerve give?
Motor to inferior pharyngeal constrictor and cricothyroid
Which branch of the recurrent laryngeal nerve supplies the larynx?
Inferior laryngeal nerve
What do the anterior and posterior branches of the inferior pharyngeal nerve give innervation to?
Motor to intrinsic muscles and sensory to infraglottic cavity
Which membrane of the larynx is incised in the midline to secure the airway?
Cricothyroid
Why is left recurrent laryngeal nerve palsy more common?
Has a longer course
What are some causes of recurrent laryngeal nerve palsy?
Idiopathic, thyroid surgery, thyroid carcinoma, oesophageal carcinoma, penetrating wounds, bronchial carcinoma, mediastinal lymph node malignancy, aortic aneurysm
What is Semon’s law?
Incomplete paralysis affects adductors first therefore affected cords remain abducted
What are the S/S of recurrent laryngeal nerve palsy?
Hoarseness/change in quality of voice, bovine cough
What is the treatment for recurrent laryngeal nerve palsy?
Teflon injections and voice therapy
What type of tumour are virtually all laryngeal carcinomas?
SCCs
Which area of the larynx is predominantly affected by carcinoma?
Glottis
What is the male and female distribution of laryngeal carcinoma?
Four times more common in men
What age range is most commonly affected by laryngeal carcinoma?
3/4 of pts >60 y.o.
What are the risk factors for laryngeal carcinoma?
Smoking, occupational exposures, HPV16
What are the S/S of laryngeal carcinoma?
Chronic hoarseness, pain, dysphagia, neck lump, persistent cough, earache, weight loss, loss of laryngeal crepitus
How is laryngeal carcinoma investigated?
CXR, flexible laryngoscopy, fine-needle aspiration, CT, MRI
What treatment is available for laryngeal carcinoma?
Radiotherapy +/- chemotherapy, laryngectomy, palliation
How does the prognosis of laryngeal carcinoma vary depending on its location?
Glottis has good prognosis whereas subglottis is poor
Why does the carcinoma in the glottis have a good prognosis?
Presents early with hoarseness
What are the different procedures used in thyroid surgery?
Thyroid lobectomy, sub-total thyroidectomy, total thyroidectomy
Describe sub-total thyroidectomy.
Leave enough gland to retain hormone function to avoid lifelong medication
When is total thyroidectomy preferred?
Malignancy
What complications are associated with thyroid surgery?
Bleeding –> tracheal compression, RLN –> partial airway obstruction, hypoparathyroidism, thyrotoxicosis storm, SLN
Why is superior laryngeal nerve injury generally only noticed by professional singers?
Causes an inability to create high-pitched sound
What are the S/S of thyrotoxic storm?
Hyperexia, HR>140 bpm, nausea, jaundice, vomiting, confusion, delirium, seizures
