s10. larynx and conditions Flashcards
What are the functions of the larynx?
- airway protection
- ventilation
- cough reflex
- phonation
What is the relation of the larynx to the hyoid bone?
it is suspended from an lies below the hyoid bone
What is the larynx?
part of the upper respiratory tract that begins at the laryngeal inlet and ends at the lower border of the cricoid cartilage (C6), when it then continues on as the trachea
What is the relation of the larynx to the laryngopharynx?
lies anterior to it
What is the piriform fossa and its function?
it is formed by the laryngopharynx as it cups around the laryngeal inlet- collects food and fluid that moves over the epiglottis, protecting the airway
What are the laryngeal cartilages?
- the epiglottis
- Arytenoid cartilages
- Cricoid cartilage
What are the Arytenoid cartilages?
Pyramid-like cartilaginous structures that form the posterior attachment of the true vocal cords- they are found at the back of the cricoid cartilage
What is the cricoid cartilage?
a complete ring of cartilage that connects the larynx to the trachea
What synovial joints are present in the larynx?
- cricothyroid
- cricoid arytenoid
What is the thyrohyoid membrane?
membrane between thyroid cartilage and hyoid bone which suspends the larynx from the hyoid
What is the cricothyroid membrane and what is its importance?
connects thyroid cartilage to cricoid cartilage-we carry out a cricothyroidotomy here
What is the use of a cricothyroidotomy?
provides emergency access to to the airway beneath the vocal cords when the patient is unable to be intubated or ventilated
What is the position of the vocal cords at different pitches?
- at HIGH PITCH the vocal cords are pulled taught by the cricothyroid muscles
- at LOW PITCH the vocal cords are less taught
What is the innervation of the cricothyroid muscle and what is its clinical relation?
the external branch of the superior laryngeal nerve (a branch of CNX)
CLINICAL RELATION
- runs in close proximity to the superior thyroid artery so a risk of injury in thyroid surgery resulting in hoarse voice when attempting higher pitches
What is laryngitis?
inflammation of the larynx, often involving the true vocal cords
How does laryngitis present? -hoarse weak voice
-sore throat
-history URT
-viral and non infectious aetiology
SELF LIMITING
what are laryngeal nodules?
benign growths of the vocal cords caused by acute trauma or chronic irritation
How do laryngeal nodules present?
- hoarse voice for more than 3 weeks
- requires visualisation of vocal cords and biopsy to rule out cancer
What can cause laryngeal oedema?
allergic reaction or swallowed foreign body
What is epiglottitis?
inflammation of the epiglottis and supraglottic tissues usually affecting children-often haemophilus
How does epiglottitis present?
difficulties breathing difficulties swallowing and drooling high fever sore throat sniffing position
How do we manage epiglottitis?
DO NOT EXAMINE THROAT AS CAN CAUSE DETERIORATION INTO COMPLETE AIRWAY OBSTRUCTION
- intubation or tracheostomy
- antibiotics
What is croup?
a viral respiratory infection that infects the larynx and trachea in children between 6 months and 3 years
How does croup present?
- barking cough, most mild and doesnt need hospitalisation
- severe symptoms such as stridor, resp distress and cyanosis will present to hospital and may need oxygen and steroids
How is the airway normally maintained?
actively held open by muscles and has protective reflexes such as gag reflex requiring complex neural pathways- decreased consciousness can depress these reflexes
