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Flashcards in Larynx, laryngeal muscles Deck (58):

connections of larynx

-Covered anteriorly by : infrahyoid muscles
-laterally by lobes of thyroid gland (also closely related to
major vessels)
-posteriorly esophagus => clinical relevance; Sellick's


Sellick's manoeuvre

aka. cricoid presure manoeuvre
During emergency intubation, pressure can be applied to the cricoid cartilage of larynx to occlude the esophagus =>prevents regurgitation of gastric content


What makes up the laryngeal skeleton?

-Thyroid cartilage
-Cricoid cartilage
-Arytenoid cartilage
-Epiglottis cartilage


Which parts of the laryngeal skeleton are Elastic cartilages?



Which parts of the laryngeal skeleton are Hyaline cartilages?



Thyroid cartilage

-Hyaline cartilage
-composed of 2 laminae (R&L) on either side of superior
and inferior notch.
-Has an oblique line on each lateral side which divides it
into ant. and post. facets
-Has inf. horn => artuculates with cricoid cartilage
-Has sup. horn =>articulates with major cornu of hyoid
-Thyrohyod membrane with lateral and medial thickenings.
Lat and median thyrohyoid ligaments.


Cricoid cartilage

-Ring-shapes, encircling airways
-has post surface; Lamina
-has Ant. surface; Arch
-Thyroid articular surface: at junction of lamina and arch on
either side (inferior most)
-Arytenoid articular surfaces: on up. border of each lamina


Cricothyroid joint

-Inf. horn of thyroid cartilage + thyroid articular surface of cricoid cartilage.
- Hinge type
-1 axis: transverse


Cricoarytenoid joint

-arytenoid articular facet of cricoid + articualar surface of
base of arytenoid cartilage
-Pivot type
-1 axis : vertical


Arytenoid cartilage

-Elastic cartilage
-Apex: -Tilted medially and posteriorly
-Carries the corniculate cartilage (of santorini) at
the tip -> sometimes apex is referred to as post.
-Base: articulate process with cricoid = has 2 processes:
-Muscular process: angled laterally and posteriorly.
-Vocal process: projects anteriorly-> attachment for vocal ligament mm


What does the muscular process give attachment to?

-Lateral cricoarytenoid m
-Post. cricoarytenoid muscle
(-Oblique arytenoid m(post aspect))
(-Thyroarytenoid m?)


What does the vocal process give attachment to?

-Vocalis mucle



-Elastic cartilage
-Has a stem/stalk (petidus) which attaches to inner surface
of thyroid cartilage => forms epiglottic tubercle on
mucosa and an oval lamina
-Ant.surface: faces pharynx and is lined with non-
keratinized stratified squamous epith.
Post surface: faces laryngeal inlet and is lined with
respiratory epithelium.
-Sieve- like character: has holes/perforations which allows
passage to small vessels and glandular tissue


Which are the extrinsic laryngeal ligaments

-Thyrohyoid membrane (inc. median and lateral thyrohyoid ligaments)
-Thyroepiglottic ligament
-Hyoepiglottic ligament
-Cricotracheal ligament


"Parts" of thyrohyoid membrane

-Median thyrohyoid ligament: is a thicheming on the centre of the membrane-> from body of hyoid bone to thyroid notch?
-Lateral thyrohyoid ligament: thickening between major cornu of hyoid bone to tip of superior horn of thyroid -> contains a small cartilage embedded :TRITICEAL catilage
-Has an opening on each side for vessels and nerves


Thyroepiglottic ligament

from inner surface of body of thyroid bone
to stalk of epiglottis


Hyoepiglottic ligament

body of hyoid bone
to upper part on anterior surface of epiglottis


cricotracheal ligament

lower margin of cricoid cart.
to 1st tracheal cart?


Intrinsic ligaments of larynx

the submucosal CT of larynx is abdindant with elastic fibers and iss collectiely referred to as the fibro elastic membrane.
firbroelastic membra is compoed of a Quadrangular membrane and the triangular membranes. (or just conus elasticus)


Quadrangular membrane

-Makes up the upper portion of the fibroelastic membrabe
-goes from lateral margin of epiglottis, within the
Aryepiglottic fold to the aryteonid (apex?) and the
corniculate cartilages.
-Has a free inferior border with a terminal thickening
which makes up the VESTIBULAR LIGAMENT. (false
vocal cord)
-Has a free superior margin as well which is covered
by/with Aryepiglottic fold mucosa.


borders of Quadrangular membrane

-Anterior: fixed to lateral edge of Epiglottis
-Posterior: Fixed to Arytenoid cartilages
-Sup: free margin, embedded in aryepiglottic fold mucsa
-Inferior: free margin, forms vestibular ligament. (last3d?)


Triangular ligament:

-old way to describe! its basically half a conus elasticus?


Conus elasticus

-the lower half of the fibroelastic membrane
- From inner surface of cricoid cartilages to vocal ligament.
-superior edge is free forming the vocal ligament
-lateral attachment goes from sup. inner border of cricoid to inner surface of thyroid angle
-posteriorly it attaches to the tip of the vocal process of the arytenoids
- Has a Median cricothyroid ligament


Median cricothyroid ligament

is the anterior (middle) thickening of conus elassticus (or and border of triangular memb?)
its composed mainly of elastic fibers.


why is the vocal fold thicker than the vestibular fold?

Because of the vocalis muscle which runs right on the side of the vocal ligament.


which are the extrinsic muscles of the larynx?

The Cricothyroid muscle is the only extrinsic muscle of the larynx


what is the action and innervation of the Cricothyroid muscle?

It is located on anterios aspect of thyroid bone
it pulls the thyroid bone forward and downwards stretching the vocal ligament
-control the rough tension of the voice
responsible for high pitch sounds

-Its the only laryngeal muscle which is innervated by the (external branch of the) Superior laryngeal nerve (Vagus)


origin and insertion of cricothyroid muscle

O: Anterior surface/arch of cricoid cartilage
I: Wing or inf horn of thyroid cartilage


which are the intrinsic laryngeal muscles?

All the rest
-Lateral cricoarytenoid
-Posterior cricoarytenoid
-Oblique/transverse arytenoids


Posterior cricoarytenoid

O: Both sides of post sufrace (lamina) of cricoid cartilage
I: Muscular processes of arytenoids
Action: Pulls arytenoids backwards (and rotates them
laterally) causing rima glottidis to open (widen)
Innervation : ext. branch of inf. laryngeal n. (from recurrent
laryngeal nerve)


Posterior cricoarytenoid

O: Both sides of post sufrace (lamina) of cricoid cartilage
I: Muscular processes of arytenoids
Action: Pulls arytenoids backwards (and rotates them
laterally) causing rima glottides to open (widen)
Innervation : ext. branch of inf. laryngeal n. (from recurrent
laryngeal nerve)


which muscle is the only laryngeal muscle which opens (Widens) the Rima glottides?

posterior cricoarytenoid


Lateral cricoarytenoid muscle

O:upper margin of ant surface (arch) of cricoid cartilage
I: muscular processes of arytenoids.
Action: pulls aryteonid forward (int. rotation) to close (narrow) Rima glottides



O: inner surface of thyroid cartilage (from thyroid angle
and a little bit of the cricothyroid membrane)
I: outer (ant.) surface of arytenoid (and muscular process)
Action relaxes vocal cord controls soft tension of vocal cord => responsible for lower pitch sound.
(haythams says that it closes rima glottidis tho)

-Action: relaxes vocal cord : lower pitch ounds

-Some believe the thyroepiglottis muscle and the vocalis muscle are parts of the Thyroarytenoid muscle.


Thyroepiglottic muscle

O: Inner surface of thyroid cartilage with thyroarytenoid m.
=>common origin
I: Epiglottis ( X surface)
Action: Depresses base of epiglottis, constricting the
laryngeal inlet
thought to be part of thyroarytenoid m.


vocalis musle

0: post./inner surface of thyroid cart.
I: vocal process of arytenoids (and all along vocal lig)
Action: shortens (relaxes (relieves tension of) vocal cord => for lower pitch sound--> controls soft tension


which are the inter arytenoid muscles?

oblique and transverse arytenoid musscles


Oblique arytenoid muscle

O/I :post aspect of muscular process (or just post surface?)
of one arytenoid and the posterior aspect of the apex of opposite arytenoid.
Action: Narrows rima glottides


Transverse arytenoid muscle

O/I: Posterior and lateral surface of each arytenoid cartilage
Action: Adducts the arytenoids (pushes them medially, closer to each other) thus closes the Rima glottides


Aryepiglottic muscle

-thought to be an extension of oblique arytenoid
continuing from apex of arytenoids to sides of epiglottis
Action: assists funclior of aryepiglottic m => closes laryngeal inlet.


Aryepiglottic folds

run from both sides of epiglottis to arytenoid carttilage


Piriform recess

find them between aryepiglottic folds and thyroid cart.
they direct the food away from laryngeal inlet and down to esophagus.


Plica Nervi Laryngei

Laryngeal nerve folds: they run across the piriform recess and are seen in the mucosa
they are formed by the underlying superior laryngeal nerve and vessels.


Borders of laryngeal inlet

Ant: superior edges of epiglottis
Post: mucosa between arytenoid cartilages
Laterally: the Aryepiglottic folds


vestibule of larynx

the cavity/space from inlet to vestibular folds or rima glottides.


borders/walls of vestibule

Ant wall: epiglottis
Posterior wall: the mucosa over the arytenoids
Lateral walls: the Quadrangular membranes


Rima vestibuli

is the space /interval between the 2 false vocal cords (vestibular folds)


Rima glottides

is the space/ interval between the 2 true vocal cords.
-Has an intramembranous part and an intercartilagenous part.


Glottis Vocalis

-Is the intermembranous part of Rima Glottides
-its the portion of the opening which is anterior to the vocal processes of the arytenoids, bounded by the vocal ligaments. (so in centre???)


What mucle causses wispering and how

The Lateral cricoarytenoid m.
It closes the glottis vocalis.


Glottis Respiratoria

Aka. interarytenoid space
Is the intercartilagenous part of Rima Glottides. (2/5ths)
-the part of the opening which is between the ocal processes of the arytenoid cartilages.
-its open during phonation and the valsava manoeuvre
-Its closed during wispering


sensory innervation of larynx

-Internal branch of superior laryngeal nerve (vagus) innervate above vocal fold
-Internal branch of inferior laryngeal n (recurrent laryngeal)
innervate below vocal fold
OBS. remember that internal branches are sensory and external branches are motor


Blood supply of larynx?

-Superior laryngeal a: upplies mucosa and muscles of upper part of larynx
-Inferior laryngeal a: suppliess muscles and mucosa of lower part of larynx


Superior laryngeal a

ECA=>Superior thyroid a=>superior laryngeal a
=> enters through opening in thyrohyoid membrane together with superior laryngeal n


Inferior laryngeal a

subclavian a=> thyrocervical trunk=> inferior laryngeal a
=>ascends to larynx with recurrent laryngeal n
enters beneath the lower border of inf. consstrictor m.


Broyles ligament

A mass of collagenous tissue at the anterior most portion of the vocal fold
attaches to the inner area of the thyroid cartilage which is devoid of perichondrium.


formal tracheosstomy

cut in 2nd and 3d tracheal rings when not emergency


Emergency cricothyroidotomy

through cricothyroid membrane anteriorly where there are no muscles imp vessels and nrves .