Download anatomy and physiology of the larynx

ANATOMY AND PHYSIOLOGY
OF THE LARYNX
Yard.Doc.Dr.Müzeyyen Doğan
Learning goal and objectives of
the lesson
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Learning goal of the lesson: The
learner should know the basic anatomic
structures, embryology and physiology of
the larynx
Learning objectives of the lesson the
learner will be able to
identify the anatomic structures of the
larynx
identify the physiology of the larynx
LARYNX
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Adult: between 3th and
6th cervical vertebra
İnfant: between 1st and
4th cervical vertebra
Attaches to the hyoid
bone and opens into the
laryngopharynx superiorly
Continuous with the
trachea posteriorly
Embryology I


Respiratory primordium
 Third week– 26 days
Respiratory primordium separated by tracheoesophageal
folds
 Fuse to form septum (4-5 weeks)
Embryology II
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Larynx from 4th and
5th arches
Primitive larynx
altered by
hypobranchial
eminence, epiglottis,
arytenoids
Laryngeal lumen
obliterated and
recanalized
Differences in adults and infants
●
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1/3 size at birth
Narrow dimensions (subglottis vs. glottis)
Higher in neck and more pliable
Epiglottis narrower
Framework of the Larynx
Osseous Structure
HYOID BONE
 Greater cornu(cornu majus)
 Lesser cornu (cornu minus)
 Corpus hyoideum (body)
Cartilage -1
unpaired cartilages
thyroid, cricoid, and
epiglottis
 paired cartilages
arytenoids,
corniculates, and
cuneiforms

Cartilage -2
Epıglottic Cartilage
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
This leaf shaped
cartilage is composed
mainly of elastic
cartilage
elastic cartilage that
covers the laryngeal
inlet during
swallowing
Thyroid cartilage
The thyroid cartilage is
also known as the Adam’s
apple. It is a large Vshaped cartilage that
houses and protects the
vocal cords and the
opening to the trachea.
The vocal cords attach to
the thyroid cartilage at
the front of the neck, just
under the epiglottis.
Cricoid cartilage
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Arcus cricoidea
Lamina cricoidea
The cricoid cartilage
may be regarded as
the base and support
for the entire larynx.
Paired cartilages

arytenoids,
corniculates, and
cuneiforms
Arytenoid cartilage
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Pyramidal shape
Joint with corniculate cartilage.
Processus vocalis lig.vocale
Processus muscularis
m.cricoaritenoideus lateralis and
posterior
Joints
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CRICOTHYROID JOINT
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CRICOARYTENOID JOINT
Cricoarytenoid Joint

Cricoid cartilage
articulates with the
arytenoids via the
cricoarytenoid
joints. (synovial
joint).
Cricothyroid Joint

Cricoid cartilage
articulates with the
thyroid cartilage via
the cricothyroid
joints (synovial
joint)
Ligaments and Membranes I
extrinsic ligaments
 thyrohyoid
membrane
 thyrohyoid
ligaments
 thyroepiglottic
ligament,
 hyoepiglottic
ligament,
 cricotracheal
Ligaments and Membranes II
intrinsic ligaments
 quadrangular
membrane
 vestibular ligament
 conus elasticus
 median
cricothyroid
ligament
 vocal ligament
Thyrohyoid membran

This broad fibroelastic
sheet is attached from
the superior border
and the superior horn
of the thyroid
cartilage to the
posterior surface of
the body and greater
cornua of the hyoid
bone )
Conus Elasticus
This membrane arises
from the inner surface
of the cricoid arch
Quadrangular Membrane

It extends from the
lateral margins of the
epiglottis within the
aryepiglottic fold and
attaches to the arytenoid
and corniculate
cartilages. The inferior
free edge is thickened to
form the vestibular
ligament (false vocal
cord). The superior edge
is also free and it is
covered with aryepiglottic
Vocal cords
Örtü-Gövde (Hirano)
 Epitel
 Reinke tabakası
 Vokal ligaman
 Vokalis kası
Larinks Kasları
Intrinsic muscles:
cricothyroids, posterior cricoarytenoids, lateral
cricoarytenoids, transverse arytenoid, oblique
arytenoids, and thyroarytenoids
extrinsic muscles :
strap muscles
Intrinsic Muscles
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Cricoarytenoid
Cricothyroid
Interarytenoid
Thyroarytenoid
Thyroepiglottic
muscles
Extrinsic muscles
Infrahyoid muscles
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Omohyoid
Sternohyoid
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Sternothyroid
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Thyrohyoid
Extrinsic muscles
Suprahyoid muscles
 digastric
 geniohyoid
 mylohyoid
 stylohyoid
 stylopharyngeus
 thyrohyoid .
Suprahyoid muscles
Intrinsic Muscles
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abduction of the vf.
 Posteroir
cricoarytenoid m
adduction of the vf
 thyroarytenoid /
vocalis muscle
 Lateral
cricoarytenoid m
 İnterarytenoid and
obliq muscles
tension of the vf.
krikotiroid m
m.interarytenoideus


Transvers Part:
Adduction of the vocal
folds by approximating
the arytenoid cartilages
Obliq Part: Sphincter of
the inlet of the larynx
during the act of
swallowing Closes
laryngeal inlet by
approximating arytenoid
cartilages.
m.cricoarytenoideus
m.cricoarytenoideus posterior
abductor of the vocal cords

m.Cricoarytenoideus lateralis
closes the glottis by adducting the vocal folds

m.tyroaritenoideus
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Thyroarytenoideus
internus or vocalis
muscle is the major
tensor of the free edge of
the vocal fold.
Thyroarytenoideus
externa contraction
draws the arytenoid
cartilages foreward
toward the thyroid, thus
shortening the vocal
ligament.
Thyroepiglotticus
widens the inlet of the
larynx
m.cricothyroideus
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The CT produces
elongation and tension of
the vocal fold ligament by
elevating the arch of the
cricoid cartilage upward
toward the lowermost
aspect of the thyroid ala.
Contraction of the CT also
rotates the arytenoids
medially, adducting the
vocal folds.
Innervation
external branch of the
superior laryngeal nerve
Intrinsic Muscles
Vascular System
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Arterleri a.thyroidea superior ve
inferiordan gelir
Venleri (v.laringea superior ve inferior)

v.thyroidea superior ve inferior

v.jugularis interna
Arterial Drainage

a.carotis eksterna

a.thyroidea superior

a.laryngea superior
a.cricothyroideus
Subclavian arter

Turuncus thyroservicalis

A.thyroidea inferior

A.laryngea inferior
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Arterial Drainage
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SUPERIOR
LARYNGEAL A.
INFERIOR
LARYNGEAL A.
CRICOTHYROID
ARTER
Venous Drainage
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SUPERIOR
LARYNGEAL V.
INFERIOR
LARYNGEAL V.
Lymphatic Drainage
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Glottik bölgenin lenf
drenajı zayıf
Suprglottik bölgenin
lenf drenajı derin
servikal lenf nodları
Subglottik bölgenin
lenf drenajı alt
derin servikal lenf
nodları, pretrakeal
lenf nodları,
prelaringeal lenf
nodları
Nerve -1

Recurrent laryngeal
nerve
 Motor to all intrinsic
muscles
 Sensory to infra-glottic
area
 Frequency dependent
Superior laryngeal
nerve
 Supra-glottic afferent
(int.)
 Cricothyroid muscles
Nerve -2
Internal cavity of the larynx
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supraglottic space
(also called the vestibule
which is surrounded by
the piriform fossa)
preepiglottic space
paraglottic space
(which contains the
ventricles)
subglottic space (which
is the area below the true
vocal folds).
supraglottic space
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Superior border : free
margin of the
epiglottis and
aryepiglottic folds
Inferior border: lower
margin of the
ventricular or false
vocal folds
preepiglottic space
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Superior border :
hyoepiglottic ligament
Anterior border:
thyrohyoid membrane
and ligament
Posterior border:
anterior surface of the
epiglottis and
thyroepiglottic
ligament
supraglottic space
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Superior border : free
margin of the
epiglottis and
aryepiglottic folds
Inferior border: lower
margin of the
ventricular or false
vocal folds
paraglottic space
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Superior border :
quadrangular
membrane
Inferior border:
conus elasticus
Lateral border:
inner surface of the
thyroid cartilage
Medial border:
ventricle
Laryngeal Histology
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It is lined mainly by a pseudostratified, ciliated,
columnar epithelium .
It also contains a mucosa with laryngeal glands
and a few taste buds.
The true vocal folds have a specialized histology
different from the rest of the larynx.
Virtually all the laryngeal membranes and
ligaments consist of elastic and collagenous
fibers.
All the laryngeal muscle is cross-striated muscle.
Laryngeal Physiology
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1.protection
2.respiration
3.phonation
4.effort closure
Speech Production
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begins in cerebral cortex
precentral gyrus to motor nuclei then
coordinated activity
Phonation
Myoelastic - aerodynamic theory
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1.glottis closed
2.subglottal pressure increases
3.vocal folds are blown open in a zipper-like
fashion (from lower towards the upper lip)
4.glottis open
5.subglottal pressure decreases
6.recoiling forces and the Bernoulli effect adduct
the vocal folds back together (also in a zipperlike fashion with the edges of the lower lip
closing first)
Phonatory cycle
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vocal folds approximated
infraglottic pressure builds up
pressure opens folds from bottom up
upper portion with strong elastic properties
Movements of Vocal Cords
PHONATION
Physıcal Examination I
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Inspection
Palpation
Indirect Laryngoscopy
Direct Laryngoscopy
Radiography
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Neck films, chest films
Barium swallow
CT/MRI
Physical Examination Iı
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Videolaryngostroboscopy
Glottography
Laryngeal EMG
CADAVER I
CADAVER II
CADAVER III