The Larynx
The larynx (voice box) is an organ located in the anterior neck. It is a component of
the respiratory tract, and has several important functions, including phonation, the
cough reflex, and protection of the lower respiratory tract.
The structure of the larynx is primarily cartilaginous, and is held together by a series
of ligaments and membranes. Internally, the laryngeal muscles move components of
the larynx for phonation and breathing.
In this article, we will discuss the anatomy of the larynx – its location, structure,
vasculature and innervation. We shall also consider its clinical relevance.
Fig 1 -Anatomical position of the larynx (yellow) in the neck. It is continuous with
the trachea inferiorly and the pharynx superiorly.
Anatomical Position and Relations
The larynx is located in the anterior compartment of the neck, suspended from the
hyoid bone, and spanning between C3 and C6. It is continuous inferiorly with the
trachea, and opens superiorly into the laryngeal part of the pharynx.
, It is covered anteriorly by the infrahyoid muscles, and laterally by the lobes of the
thyroid gland. The larynx is also closely related to the major blood vessels of neck,
which ascend laterally to it.
Posterior to the larynx is the oesophagus. This is of clinical relevance during
emergency intubation – as pressure can be applied to the cricoid cartilage of the
larynx to occlude the oesophagus, and thus prevent regurgitation of gastric contents
(known as cricoid pressure or Sellick’s manoeuvre).
Anatomical Structure
The larynx is formed by a cartilaginous skeleton, which is held together by ligaments
and membranes. The laryngeal muscles act to move the components of the larynx
for phonation and breathing. More information about each of these structures can
be found in their respective sections.
Anatomically, the internal cavity of the larynx can be divided into three sections:
Supraglottis – From the inferior surface of the epiglottis to the vestibular folds
(false vocal cords).
Glottis – Contains vocal cords and 1cm below them. The opening between the
vocal cords is known as rima glottidis, the size of which is altered by the muscles of
phonation.
Subglottis – From inferior border of the glottis to the inferior border of the cricoid
cartilage.
The interior surface of the larynx is lined by pseudostratified ciliated columnar
epithelium. An important exception to this is the true vocal cords, which are lined
by a stratified squamous epithelium.
Vasculature
The arterial supply to the larynx is via the superior and inferior laryngeal arteries:
Superior laryngeal artery – a branch of the superior thyroid artery (derived from
the external carotid). It follows the internal branch of the superior laryngeal nerve
into the larynx.
The larynx (voice box) is an organ located in the anterior neck. It is a component of
the respiratory tract, and has several important functions, including phonation, the
cough reflex, and protection of the lower respiratory tract.
The structure of the larynx is primarily cartilaginous, and is held together by a series
of ligaments and membranes. Internally, the laryngeal muscles move components of
the larynx for phonation and breathing.
In this article, we will discuss the anatomy of the larynx – its location, structure,
vasculature and innervation. We shall also consider its clinical relevance.
Fig 1 -Anatomical position of the larynx (yellow) in the neck. It is continuous with
the trachea inferiorly and the pharynx superiorly.
Anatomical Position and Relations
The larynx is located in the anterior compartment of the neck, suspended from the
hyoid bone, and spanning between C3 and C6. It is continuous inferiorly with the
trachea, and opens superiorly into the laryngeal part of the pharynx.
, It is covered anteriorly by the infrahyoid muscles, and laterally by the lobes of the
thyroid gland. The larynx is also closely related to the major blood vessels of neck,
which ascend laterally to it.
Posterior to the larynx is the oesophagus. This is of clinical relevance during
emergency intubation – as pressure can be applied to the cricoid cartilage of the
larynx to occlude the oesophagus, and thus prevent regurgitation of gastric contents
(known as cricoid pressure or Sellick’s manoeuvre).
Anatomical Structure
The larynx is formed by a cartilaginous skeleton, which is held together by ligaments
and membranes. The laryngeal muscles act to move the components of the larynx
for phonation and breathing. More information about each of these structures can
be found in their respective sections.
Anatomically, the internal cavity of the larynx can be divided into three sections:
Supraglottis – From the inferior surface of the epiglottis to the vestibular folds
(false vocal cords).
Glottis – Contains vocal cords and 1cm below them. The opening between the
vocal cords is known as rima glottidis, the size of which is altered by the muscles of
phonation.
Subglottis – From inferior border of the glottis to the inferior border of the cricoid
cartilage.
The interior surface of the larynx is lined by pseudostratified ciliated columnar
epithelium. An important exception to this is the true vocal cords, which are lined
by a stratified squamous epithelium.
Vasculature
The arterial supply to the larynx is via the superior and inferior laryngeal arteries:
Superior laryngeal artery – a branch of the superior thyroid artery (derived from
the external carotid). It follows the internal branch of the superior laryngeal nerve
into the larynx.
