The Larynx The Hypopharynx The Oropharynx class2014-20… · The larynx: -A cartilaginous structure...
Transcript of The Larynx The Hypopharynx The Oropharynx class2014-20… · The larynx: -A cartilaginous structure...
The Larynx
The Hypopharynx
The Oropharynx
To describe the laryngeal skeleton & membranes
To analyze the function of laryngeal parts in relation
to its anatomy.
To describe oro- & hypo-pharynx
Case scenario …
A 40 years old female teacher consulted
the ENT surgeon for change in her voice
which became hoarse over the last few
weeks, hoarseness was interrupted by
periods where she looses her voice
completely, there was also laryngeal
discomfort & attacks of dry cough.
Fibreoptic laryngoscopy showed a big
polyp in her left cord.
Decision for excision of this polyp was
made by direct laryngoscopy.
The larynx:
-A cartilaginous structure that serves as a
passageway for air between the pharynx and
the trachea
-Lies in the anterior midline (C4-C6)
-Upper part is triangular in section
-Lower part is rounded in section
Ph
Relations:
*Anterolaterally; Thyroid gland & strap muscles
*Laterally; Carotid sheath
*Posteriorly; Pharynx
Functions:
1- Valve action; during
swallowing.
2- Phonation.
3- Building intra-abdominal
pressure.
4- Respiration.
1 2
3 4
Single Pair
1 Thyroid 4 Arytenoid
2 Cricoid 5 Corniculate
3 Epiglottis 6 Cuneiform
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2 2
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3
3
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4 4
Laryngeal cartilages:
The thyroid cartilage:
•Two quadrilateral laminae meet in the midline
•The meeting angle is 90O in male & 120O in female (Adam’s apple)
•The cartilage articulates by its inferior horns with the cricoid cartilage
Parts of the thyroid cartilage:
The cricoid cartilage:
•It is the lowest part of larynx (C6 level)
•Ring-like with anterior arch & posterior broad
lamina
•It provides two pairs of synovial joints:
1- For the inferior horns of thyroid cartilage;
on each side.
2- For the arytenoids; on the lamina.
arch
lamina
2
1
Joints (synovial):
1- Cricothyroid; permits rocking movement
of thyroid on cricoid (forward & backward
bending).
2- Cricoarytenoid; permits sliding &
rotation of the arytenoid on cricoid lamina.
1
2
The arytenoid cartilage:
•Three sided pyramid
•The base sits on the cricoid shoulder &
carries three processes, two are
important:
1- The anterior (vocal) process: for vocal
cord
2- The lateral (muscular) process: for
muscles
1 2
1 2
The epiglottis:
•Elastic, leaf-like cartilage
•Attached by its base to the back of the thyroid
cartilage in the midline
•Its upper part stands behind the posterior third
of the tongue
•Attached by its sides to the arytenoids by the
quadrate membrane
The quadrate membrane:
Has four borders:
1- Anterior; to the epiglottis
2- Posterior; to the arytenoids
3- Upper; free, called ary-epiglottic fold
4- Lower; free, called vestibular fold (false cord)
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4
Laryngeal membranes:
The thyro-hyoid membrane:
-From upper border of thyroid cartilage to
the hyoid bone
-Forms the lateral boundary of the
pyriform recess
The pyriform recess:
-Lies between the thyrohyoid membrane
laterally & quadrate membrane medially.
-It is outside the laryngeal cavity
-It is common site for fishbones & foreign
bodies lodgement
The conus elasticus:
-Is ½ a cylinder
-Lower attachment to cricoid arch
-The ends of the free upper border are attached to the vocal processes of the
arytenoid forming the vocal cord
-Anterior attachment to the thyroid cartilage
-Movement of arytenoids on the cricoid cartilage will move the vocal cords
Laryngeal inlet:
Is an inverted vertical triangle:
•Base; epiglottis
•Sides; ary-epiglottic folds
The cavity of the Larynx
The vestibule:
-The distance from inlet to vocal cords
-Lies between the two quadrate membranes
-Features:
1- The vestibular folds
2- The laryngeal ventricle; mucosal hernia
between the true & false cords
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2
The vocal folds:
-The anterior 3/5 (conus)
-Posterior 2/5 (vocal process)
-Vocalis; muscle fibers in the vocal cord,
increases the apposed surface area
-Rima glottidis; openings between the cords
-Glottis ; laryngeal diameter at the level of the
vocal cords
The rima glottidis:
-Is 23 mm long in male & 17 mm in female
Movements:
1- Phonation; cords are just touching each other.
2- Quite respiration; V shape opening, by sliding of the arytenoids on the
cricoid lamina.
3- Forced respiration; diamond shape opening, by rotation of the arytenoids on
the cricoid lamina.
1 2 3
Act on vocal cords Act on inlet
Tension Sphincteric Sphincteric
Shorten Lengthen Open Close Open Close
Thyroarytenoi
d (6)
Cricothyroid
(5)
Posterior
crico-arytenoid
(4)
Transverse
arytenoid (2) Elastic
recoil
Aryepiglottic
(1) Lateral crico-
arytenoid (3)
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2
3 4
6 5
Laryngeal muscles
Arteries of the larynx:
1- Superior laryngeal artery;
-From the superior thyroid artery
-Pierces the thyrohyoid membrane to lie in the
floor of the pyriform recess
-Supplies the supraglottic part
2- Inferior laryngeal artery;
-From the inferior thyroid artery
-Enters the larynx deep to the inferior
pharyngeal constrictor
-Supplies the glottic & infraglottic parts
Veins accompany arteries
Nerves of the larynx:
Motor:
All muscles of the larynx are supplied by the
recurrent laryngeal nerve except cricothyroid
(external laryngeal nerve)
Sensory:
•Supraglottic part: internal laryngeal nerve
•Infraglottic & glottic parts: recurrent laryngeal
nerve
The laryngopharynx:
•The part of the pharynx opposite to
laryngeal inlet
•It is characterized by:
1- One median glosso-epiglottic fold
2- Two lateral glosso-epiglottic folds
3- The valleculae; on each side of the
median glosso-epiglottic fold
4- The pyriform recess
2 2
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4
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4
3 3
The oropharynx:
•The part of the pharynx behind the oral
cavity
•Limited anteriorly by the palatoglossal
fold
•Supplied by pharyngeal branch of IX
•Structures in this part are:
1- Faucial pillars (palatoglossal &
palatopharyngeal folds)
2- Lingual tonsils
3- Palatine tonsils
2
1 3
1
The palatine tonsils:
•Lie between the 2 pillars (tonsillar fossa)
•The part above it is called supratonsillar
recess
•Characterized by surface crypts
•Surrounded by tonsillar capsule
•Supplied by branches from facial, palatine
& pharyngeal arteries
chronic acute
Tonsillitis