The larynx Flashcards
What is the only complete circle of cartilage around the respiratory inlet?
The cricoid cartilage
What are the two functions of the larynx?
Production of voice
Acts as valve to prevent food and foreign bodies entering lower respiratory passages
How does the larynx vary between men and women?
Larynx is shorter in females
Where is the laryngopharynx found?
Behind the larynx, infront of C4-6 vertebrae
What is the inferior cornu and what does it articulate with?
Part of thyroid cartilage that forms synovial joint with cricoid cartilage
How is the epiglottis attached to the tongue?
By a median and two lateral glosso-epiglottic folds
On either side is the valleculae
How is the epiglottis attached to the arytenoid cartilages?
Aryepiglottic folds on the side
Form the lateral margins of the laryngeal inlet
What are the two processes of the arytenoids called?
Muscular and vocal processes
What is the slit between the two vocal cords called? Function?
The rima glottis,
Acts as a sphincter in coughing and sneezing
Where are the vocal folds found?
Attached between vocal processes of arytenoids and thyroid cartilage
What is the quadrangular membrane?
Fibroelastic membrane between epiglottis and arytenoids, thickened below to form vestibular ligament (false vocal cord)
Where do objects get stuck in the larynx?
In the space lateral to the aryepiglottic folds (Piriform fossa)
What is the lower border of the larynx?
The lower border of the cricoid cartilage, turns into trachea
How does the mucosa of the vocal folds differ from the rest of the larynx?
Over the vocal folds it is keratinized stratified squamous epithelium, the rest of the larynx is respiratory (ciliated pseudostratified columnar epithelium w/mucous glands)
Which muscles work by rotating arytenoids?
Lateral and posterior cricoarytenoid
What is the action and innervation of the lateral cricoarytenoid?
Closes glottis through medial rotation of arytenoids
Recurrent laryngeal nerve
What is the action and innervation of the posterior cricoarytenoid?
Separates vocal processes and cords by lateral rotation of arytenoids
Recurrent laryngeal nerve
What is the action and innervation of cricothyroid muscle?
Tightens vocal cords by rotating thyroid cartilage downwards and forward
External laryngeal nerve
What is the action and innervation of the vocalis muscle?
Regulates tension of vocal cords
Recurrent laryngeal nerve
What is the action and innervation of the transverse arytenoid muscle?
Closes posterior part of rima glottis
Recurrent laryngeal nerve
What is the action and innervation of the oblique arytenoid muscle?
Closes rima glottis
Recurrent laryngeal nerve
What is the sensory supply of the laryngeal membrane?
Above vocal folds= internal branch of superior laryngeal nerve
Below vocal folds- recurrent laryngeal
What is the blood supply of the larynx?
Superior and inferior thyroid arteries
Name 5 possible reasons for a hoarse voice
Swollen vocal cords from infection, bilateral paralysis of cricoarytenoids, laryngeal tumours and severe dental infections
How is the frequency of sound produced by the vocal cords change?
By the length and tension of the vocal cords when vibrated and by mass of vocal cords
What innervation is needed for clear speech?
Vagus (vocal fold tension), facial (motor), trigeminal (sensory face and tongue), glossopharyneal (sensory tongue), hypoglossal (motor tongue)
What muscles oppose the actions of the mylohyoid and geniohyoid?
Infrahyoid muscles- thyrohyoid, omohyoid and sternohyoid
What muscles are involved in elevation of the tongue?
Styloglossus and palatoglossus
What would be the effects of injury to the sympathetic trunk in the neck?
Horner’s syndrome
Ipsilateral pupil constriction, ptosis (droopy eyelid), dry forehead
What symptoms would someone with a completely damaged vagus nerve have?
Palipitation, constant vomiting, feeling of suffocation
