it includes introduction, situation, cartilage, muscles, cavity, blood supply, and summary about larynx

1. By – Chirag Ajmera
Shri S.L. Saini Memorial College of Paramedical Sciences
Mjf Group of Colleges and Hospitals

2.  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.
 Organ of phonation
 Wind pipe (respiratory air passage)
 Watch dog for foreign bodies

3.  Anterior aspect of
Neck
 Inferior to pharynx
 Superior to Trachea
 Between pharynx
and trachea
 Opposite to C3- C6

4.  Superiorly- Hyoid bone, Root of tongue
 Inferiorly – Trachea
 Anteriorly- Skin, Muscles
 Posteriorly- pharynx, C3- C6
 Laterally – lobes of thyroid gland

6.  Anatomical structure
 Cartilage
 Muscles
 Membranes

7.  Supraglottis
 Glottis
 Subglottis

9.  Supraglottis – From the inferior surface of the
epiglottis to the vestibular folds (false vocal
cords).
 Glottis– Contains vocal cords 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.

11.  The vocal cords (also called vocal folds) are two bands of smooth
muscle tissue found in the larynx (voice box). The vocal cords
vibrate and air passes to produce the sound of your voice.
 The fissures between the vocal cord is called Rima Glottides
 Males and females have different vocal fold sizes. Adult
male voices are usually lower pitched due to longer and thicker
folds. The male vocal folds are between 1.75 cm and 2.5 cm in
length, while female vocal folds are between 1.25 cm and
1.75 cm in length. The vocal folds of children are much shorter
than those of adult males and females. The difference in vocal
fold length and thickness between males and females causes a
difference in vocal pitch.

13.  The laryngeal skeleton have nine
cartilages which are provides rigidity and
stability.
 They are unpaired and paired
 Unpaired cartilages
 Epiglottis
 Thyroid cartilage
 Cricoid cartilage

14. Unpaired cartilages

15.  The epiglottis is a leaf shaped plate of elastic
cartilage which marks the entrance to the
larynx. It is attached to the back of the
anterior aspect of the thyroid cartilage.
 During swallowing, the epiglottis flattens and
moves posteriorly to close off the larynx and
prevent aspiration.

17.  large, prominent structure
 it is easily visible in adult males.
 It is composed of two sheets (laminae), which join together
anteriorly to form the laryngeal prominence (Adam’s apple).
 The posterior border of each sheet project superiorly and
inferiorly to form the superior and inferior horns (also known as
cornu). The superior horns are connected to the hyoid bone via
the lateral thyrohyoid ligament, while the inferior horns
articulate with the cricoid cartilage.

19. Cricoid cartilage
 The cricoid cartilage is a complete ring
of hyaline cartilage, consisting of a broad sheet
posteriorly which is called lamina and a
much narrower arch anteriorly (signet ring in shape).
 The cartilage completely encircles the airway, marking
the inferior border of the larynx at the level of C6. It
articulates with the paired arytenoid
cartilages posteriorly, as well as providing an
attachment for the inferior horns of the thyroid
cartilage.

21.  Arytenoid cartilages
 Corniculate cartilages
 Cuneiform cartilages

22.  The arytenoid cartilages are pyramidal shaped
structures that sit on the cricoid cartilage. They
consist of an apex, base, three sides and two
processes, and provides an attachment point for
various key structures in the larynx:
 Apex – articulates with the corniculate cartilage.
 Base – articulates with the superior border of the
cricoid cartilage.
 Vocal process – provides attachment for the
vocal ligament.
 Muscular process – provides attachment for the
posterior and lateral cricoarytenoid muscles.

24. Corniculate Cartilages
 These are minor, Horn shaped of elastic
cartilaginous structures.
 They located at the apex of each arytenoid
cartilage.
Cuneiform Cartilages
 These are Club-shaped pieces of elastic
cartilage located anterior to the
corniculate cartilages.
 They have no direct attachment, but act
to strengthen the folds.

26.  The muscles of the larynx are divided into
 Extrinsic muscles.
 Intrinsic muscles.
The extrinsic muscles pass between the larynx and
parts around it.
The intrinsic muscles are confined entirely within
the larynx.

27.  The extrinsic muscles pass between the larynx and parts around it.
 The external muscles act to elevate or depress the larynx during
swallowing, that’s means these extrinsic muscles act to move the larynx
superiorly and inferiorly.
 These are divided into groups-
 Suprahyoid
 Infrahyoid
 Stylopharyngeus (a muscle of the pharynx).
 The supra- and infrahyoid muscle groups attach to the hyoid
bone. This, in turn, is bound to the larynx by strong ligaments;
allowing the whole of the larynx to be moved as one unit.
 The suprahyoid muscles and the stylopharyngeus elevate the
larynx, whilst the infrahyoid muscles depress the larynx.

28.  These muscles are located
above the hyoid bone in
the neck.
 They all act to elevate the
hyoid bone – an action
involved in swallowing.
 muscles are following-
 Digastric muscles
 Stylohyoid muscles
 Geniohyoid muscles
 Mylohyoid muscles

29. Function-
 When the two bellies of the digastric contract, they pull upward on
the hyoid bone; but if the hyoid is fixed from below,
the digastric assists in extreme opening of the mouth such as yawning
or taking a large bite of an apple.
 The mylohyoid elevates the hyoid bone, tenses the floor of the mouth.
 The Geniohyoid pulls the hyoid bone antero-superiorly, shortening the
floor of the mouth and widening the pharynx during swallowing.
 The Stylohyoid elevates and retracts the hyoid bone, elongating the
floor of the mouth during swallowing.

30.  The infrahyoid muscles or strap muscles are
a group of four paired muscles in the
anterior neck below the hyoid bone.
 These muscles are responsible for depressing
the hyoid during swallowing.
 The four muscles are:
 Sternohyoid muscle
 Omohyoid muscle
 Sternothyroid muscle
 Thyrohyoid muscle

32.  The stylopharyngeus muscle is a long and
tapered longitudinal pharyngeal muscle that
runs between the styloid process of the
temporal bone and several structure of the
pharynx and larynx.
 this muscle plays an important role
in swallowing and speaking.
 This muscle Elevates pharynx and larynx.

33.  These muscles are called intrinsic muscle
because they originate and insert on the
larynx.
 These muscles are responsible for controlling
sound production.
 They control the shape of the
 Rima Glottidis
 Length of the vocal folds
 Tension of the vocal folds

34. S.N MUSCLE FUNCTION
1. Cricothyroid lengthen and tense the vocal folds.
2. Posterior
cricoarytenoid
abduct and externally rotate the arytenoid
cartilages, resulting in abducted vocal folds.
3. Lateral
cricoarytenoid
adduct and internally rotate the arytenoid
cartilages, increase medial compression.
4. Transverse
arytenoid
adduct the arytenoid cartilages, resulting in
adducted vocal folds
5. Oblique
arytenoid
narrow the laryngeal inlet by constricting the
distance between the arytenoid cartilages
6.
Thyroarytenoid
narrow the laryngeal inlet, shortening the vocal
folds, and lowering voice pitch. The internal
thyroarytenoid is the portion of the
thyroarytenoid that vibrates to produce sound.

36.  The cavity of the larynx extends from the laryngeal
entrance to the lower border of the cricoid cartilage
where it is continuous with that of the trachea.
 It is divided into two parts by the projection of
the vocal folds, between which is a narrow triangular
opening, the rima glottidis.
 The portion of the cavity of the larynx above the
vocal folds is called the vestibule which is wide and
triangular in shape.
 It contains the vestibular folds, and between these
and the vocal folds are the ventricles of the larynx.
 The portion below the vocal folds (between the vocal
fold and the trachea) is called the infraglottic cavity.

38.  The arterial supply of the larynx is by the
superior and inferior laryngeal arteries which
are branches of the thyroid arteries.
 The venous supply of the larynx is drained by
the superior and inferior laryngeal veins.
 Lymphatic drainage- Superior and inferior
deep cervical lymph nodes

39. Introduction The larynx is a complex hollow structure located in the
anterior of the neck
Function Phonation, the cough reflex, air conduction and
protection of the lower respiratory tract
Cartilages Unpaired (3): Cricoid, Thyroid, and Epiglottis
Paired (3): Arytenoid, corniculate, and cuneiform
Muscles Extrinsic: Responsible for support and position the larynx
Intrinsic: Responsible for controlling sound production.
Cavity Two parts: Vestibule, Infraglottic cavity
Blood supply Superior laryngeal arteries
Inferior laryngeal arteries
Venous supply Superior laryngeal vein
Inferior laryngeal vein
Lymphatic
drainage
Superior deep cervical lymph nodes
Inferior deep cervical lymph nodes
Nerve supply Vagus nerve: Superior laryngeal nerves
Inferior laryngeal nerves