The document discusses the anatomy and physiology of the phonatory system, primarily focusing on the larynx and vocal folds, which are critical for sound production in human speech. It outlines the larynx's location, structure, functions, and its role in breathing and swallowing, while also explaining the physiological mechanisms behind phonation. Additionally, it describes the components of the laryngeal skeleton and the muscles involved in vocal fold movement, supported by references and educational resources.

1. (Anatomy and Physiology)
A Daisy Evangeline
PGDEI (2022-23)
Dept. of Cross Disability-Early Intervention,
NIEPID, Secunderabad

2. Contents
• Introduction
• Components of Phonatory System (Larynx &Vocal folds)
• Functions of Larynx
• Anatomy of Larynx: Location & Structure
• Laryngeal Skeleton
• Physiology ofVoice production
• Theory of Phonation
Disclaimer: All the pictures & Videos in this presentation rightly belongs to their owners. The content provided is meant for EDUCATIONAL PURPOSE only.

3. • Human language and speech require the cooperation of several physical
structures and systems.
• The biological components required for speech production are
separated into 4 different systems:
Articulatory
System
Resonatory
System
Respiratory
System
Phonatory
System
https://study.com/academy/lesson/the-physiology-of-human-language-speech.html

4. https://sandiegovoiceandaccent.com/videos/six-vocal-warm-ups-everyone-should-be-doing

5. • The second system of interest in
speech production after Respiratory
system is the Phonatory system,
which is responsible for producing
sound.
• This is a system of throat valves and
protective cartilage repurposed to
create the sounds which is
recognized as the human voice.
https://study.com/academy/lesson/the-physiology-of-human-language-speech.html
https://tenor.com/search/lungs-breathing-gifs
Click here for Video

6. • Phonation is the production of vocal sound and speech. It
is the conversion of air pressure into sound.
https://www.buzzfeednews.com/article/danvergano/scientists-grow-human-vocal-cords

7. • Phonatory System, also known as the Larynx or “voice
box”, where sound is produced. It includes: larynx and,
specifically, the Vocal folds (also called “vocal cords”)
. •Larynx
. •Vocal folds
https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=zm6118

8. • Larynx serves as a principle source of sound
for speech besides other biological
functions, such as:
1) Controls the air flow (in & out of lungs)
2) Prevents entry of food, water and other
substances into lungs.
3) Aids in swallowing
4) Enables pressure build up within the
thorax for functions such as Coughing,
Vomiting, Defecation & lifting heavy
https://www.norellehealth.com/conditions/larynx-cancer/

9. • Larynx is located at the neck region.
• The larynx sits at the front of the neck between the third and
seventh neck vertebrae (C3 to C7), where it’s suspended from
Hyoid bone and sits on top of Trachea.
Location
https://www.verywellhealth.com/larynx-anatomy-4845379 https://www.visiblebody.com/blog/anatomy-and-physiology-phonation-and-the-larynx

10. • The upper portion of this organ
is attached to the lower portion
of the pharynx, or throat, via the
hyoid bone.
• Its lower border connects to the
upper portion of
the trachea (also known as the
windpipe)
https://thancguide.org/cancer-types/throat/pharyngeal/hypopharyngeal/anatomy/

11. • The larynx is a tube like structure
with complex band of cartilages
connected by ligaments and muscles
& connecting membranes covered by
mucous membrane along with
Sensory and Motor Innervations.
• All the components together is called
the Laryngeal skeleton
structure of larynx
https://thumbs.gfycat.com/ZanyThoseArgusfish-size_restricted.gif
Click here for Video

12. Laryngeal
Skeleton
Cartilaginous
framework
Ligaments &
Membranes
Extrinsic & Intrinsic
Muscles
Sensory & Motor
Innervations
https://www.researchgate.net/figure/Anterior-view-of-larynx_fig1_260780703

13. The Cartilaginous framework of the larynx consists of:
 Three large unpaired cartilages
i. Cricoid
ii. Thyroid
iii. Epiglottis.
 Three pairs of smaller cartilages
i. Arytenoid
ii. Corniculate
iii. Cuneiform.
https://teachmeanatomy.info/neck/viscera/larynx/laryngealcartilages/

14. https://makeagif.com/gif/how-the-larynx-produces-sound-sJ9cRm
Click here for Video

15. • Thyroid cartilage also called Adam’s apple is
the largest one, named because it is like a
shield. (Greek, Thyreos = large shield) is
present anterior to Arytenoids and superior
to Cricoid cartilage.
• Cricoid cartilage is like a Signet ring shaped
and forms the top ring of trachea.
• Arytenoids are pyramidal in shape and
articulate with cricoid cartilage via oval
depressions.
https://phys.org/news/2020-08-primate-voice-evolving-rapid-pace.html
Click here for Video

16. • The epiglottis is a leaf-shaped
flap in the throat that prevents
food and water from entering
the trachea and the lungs.
• It stays open during breathing,
allowing air into the larynx.
• During swallowing, it closes to
prevent aspiration of food into
the lungs, forcing the swallowed
liquids or food to go along
the esophagus toward the
stomach instead. https://www.visiblebody.com/blog/the-wonderful-windpipe-five-awesome-facts-about-the-trachea
Click here for Video

17. https://www.youtube.com/watch?v=1NZup_VpVf4

18. • Quadrangular Membrane (A thin layer of connective tissue),
Aryepiglottic Membrane (fibro-elastic tissue), Thyrohyoid membrane
etc.,
• There are two types of ligaments (fibrous connective
tissue that connects two or more structures)
Larynx ligaments & Membranes
Extrinsic
Ligaments
• Attach the larynx to other
structures (Hyoid bone,
Trachea)
Intrinsic
Ligaments
• Connect the Larynx cartilages
b/w them.
https://www.kenhub.com/en/library/anatomy/larynx
https://teachmeanatomy.info/neck/viscera/larynx/ligaments-folds/

19. https://www.youtube.com/watch?v=mxE3rXeledY

20. • The Vocal folds are muscular
fibers and ligaments that
course from each arytenoid
to the interior of the thyroid
cartilage.
• These vocal folds move along
with arytenoids creating a
triangular shaped opening
called as Glottis. https://gfycat.com/gifs/search/larynx
Click here for Video

21. Act to elevate or depress the larynx, with most attaching to
the hyoid bone.
Extrinsic laryngeal muscles
Suprahyoid muscles
Mylohyoid
Geniohyoid
Hyoglossus
Stylohyoid
Digastric
Infrahyoid muscles
Omohyoid
Sternohyoid
Thyrohyoid
Sternothyroid
https://teachmeanatomy.info/neck/muscles/infrahyoid/
https://teachmeanatomy.info/neck/muscles/suprahyoid-muscles/

22. Intrinsic laryngeal muscles
Primarily moves the vocal
folds.
Adductors
(bring
together)
• Lateral cricoarytenoid muscles
• Inter arytenoid muscles (Transverse arytenoid muscle &
arytenoid muscle)
Abductors
(opens)
• Posterior cricoarytenoid muscles
Tensors
(stretch or
tighten)
• Cricoarytenoid muscles
• Thyroarytenoid muscle
• Some part of the vocalis muscle
https://teachmeanatomy.info/neck/viscera/larynx/muscles/
https://teachmeanatomy.info/neck/viscera/larynx/muscles/

23. https://www.youtube.com/watch?v=abuxdRFQYX8

24. Sensory & Motor Innervations
• Sensory and motor innervation of
the larynx are both achieved via
branches of the Vagus nerve, cranial
nerve X, namely the Superior
Laryngeal Nerve and Recurrent
laryngeal nerves
https://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve

25. Abductors (takes
them apart
Transverse
arytenoid muscles
Adductors (bring
together)
Lateral
Cricoarytenoids
muscle & Inter
arytenoid muscles
Vocal folds
movements
https://www.youtube.com/watch?v=DXZZpMwPeJ4

26. • The Vocal folds at rest i.e., during quite breathing
are apart from each other creating a V shaped
glottal space.
• During running speech, the folds are
a) Separated for Voiceless speech sounds
(consonants)
b) Brought together for voiced sounds (Vowels
& Diphthongs)
c) Less firmly brought together for voiced
consonants.

27. The larynx has four major functions:
• Phonation: produces sound and voice
• Breathing: allows air into the lungs
• Swallowing: elevation of the larynx to facilitate
swallowing
• Protection: prohibits entry of foreign objects into the
lungs
Physiology

28.  The power supply for speech is the expired air from
the lungs.
 During early 19th century, Helmholtz & Muller and
later by Van den Berg in 1950’s proposed a theory
“Myoelastic Aerodynamic theory of Phonation”
 Aerodynamics- The vocal folds are activated by the
airstream from the lungs
 Myoelastic- The ways in which the muscles change
their elasticity and tension to effect changes in
frequency of vibrations in the vocal cords.
How do we produce sound?
https://www.emmadeanssings.com.au/uncategorized/what-is-vocal-
resonance/
Click here for Video

29. Two types of Aerodynamic forces
produce the vibrations in vocal cords.
They are:
1) Subglottal air pressure
(applied on the lower parts of
the folds forcing them to
open)
2) Bernoulli Effect (negative
pressure that occurs as a result
of air passing b/w the folds)
https://entokey.com/aerodynamic-analyses-of-vocal-function/

30.  Sub glottal air pressure is something
which parts the vocal folds.
 During each opening, tiny puffs of air
escapes and the glottis abruptly
thus air pressure is released.
 The escape of air occurs in a very
manner i.e., usually over 100 times
second thus causing vibrations in
cords.
https://quizlet.com/321380713/laryngeal-function-in-speech-production-flash-cards/

31.  The second aerodynamic phenomenon,
Bernoulli principle is important to Voicing.
 Bernoulli effect helps in bringing Vocal cords
together.
 It is based on the observation that when a gas
or liquid current runs through a constricted
passage, the velocity (speed in a certain
direction) increases.
When air rushes through glottis at
an increased velocity, Sudden drop
in the pressure against inner sides of
vocal cords stuck them together
again
https://slideplayer.com/slide/4544607/

32. https://www.youtube.com/watch?v=JF8rlKuSoFM

33. https://www.funimada.com/thank-you/

34. References:
• Robert E Owens, Jr- Language Development-an introduction
• George H Shames, Elisabeth H.Wiig,Wayne A. Secord - Human Communication Disorders-an
Introduction
• Borden – Speech Production
• https://study.com/academy/lesson/the-physiology-of-human-language-speech.html
• https://www.ijhns.com/doi/pdf/10.5005/jp-journals-10001-1511
• https://phys.org/news/2020-08-primate-voice-evolving-rapid-pace.html
• https://www.visiblebody.com/blog/the-wonderful-windpipe-five-awesome-facts-about-the-
trachea
• Videos : 3D Anatomy Lyon https://www.youtube.com/@3danatomylyon904/videos