Structures of phonation Flashcards
What are the areas of the pharynx
Naso-pharynx, Oro-pharynx, laryngo-pharynx. It is a continous tube and is a shared space for beathing and speech
What are the respiratory tracts?
Upper - nasal cavity, pharynx,
between - larynx
Lower - trachea, bronchi, lungs
What are the respiratory tracts?
Upper - nasal cavity, pharynx,
between - larynx
Lower - trachea, bronchi, lungs
What is inferior to the Larynx?
The trachea
Diaphragm
When we inhale, the diaphragm lowers and the rib cage expands, drawing air into the lungs. As we exhale, the process reverses and air exits the lungs, creating an airstream in the trachea. This airstream provides the energy for the vocal folds in the voice box to produce sound. It is innervated by the phrenic nerve
Branches of the vagus innervate the larynx
The superior laryngeal nerve originates from the vagus nerve and provides motor innervation to the cricothyroid muscle
Recurrent laryngeal nerve: Provides motor innervation to the intrinsic muscles of the larynx (except for the cricothyroid)
What are the folds
1st fleshy structure - false vocal folds. They look red because of their high blood supply, they are shiny because they produce mucus and overlap the true vocal folds
The true vocal folds don’t have a direct blood supply. Appear white and shiny.
The vocal folds look like they are directly next to each other, but they are actually seperated by a ventricle
The process of phonation
To produce voiced sounds, the vocal folds are adducted and the subglottal pressure overcomes the resistance of the folds and they open.
This releases a burst of compressed air into the supraglottal space (known as the vocal tract)
The elastic recoil of the streched tissue combined with Bernoulli forces, returns the folds to their closed position. The cycle then repeats when the subglottal pressure is higher enough to overcome the resistance of the folds.
Adduction and abduction
Abduction: The vocal folds abduct (come apart) in order to let air in and out of the lungs during breathing. Adduction: The vocal folds may adduct (come together) to trap air in the lungs. They may also adduct to vibrate to produce vocal sound.
Role of larynx in phonation
The vocal folds are suspended across the larynx
Subglottal pressure causes the vocal folds to vibrate
Structure of the vocal folds
There are five layers and 3 anatomical divisions
- epithelium (epithelial layer)
-vocal ligament (lamina propria)
-Thyroarytenoid muscle
Structure of the vocal folds
There are five layers and 3 anatomical divisions
- epithelium (epithelial layer)
-vocal ligament (lamina propria)
-Thyroarytenoid muscle
Difference between intrinsic and extrinsic
Intrinsic - origin and insertion is within the laryngeal structure (move within structure)
extrinsic - origin outside of the laryngeal structure and insertion inside the laryngeal structure - can be separated into infrahyoid and suprahyoid (above or below hyoid bone)
Anatomical challenge
Within the pharynx, we have a cross-over pathway and this why the larynx functions to protect the airway.
Describe the larynx
It is made of cartilage and interconnecting membrane and muscles which allows it to be dynamic and flexible. It is located around C3-7 anteriorly. It is superior to the trachea. 4-5cm in length and men have a bigger one than women. Larger larynx = lower pitch.
It is innervated by CN10 = vagus nerve. There are internal and external branches - superior laryngeal nerve and the recurrent laryngeal nerve.
What is the function of the larynx
Primary - airway protection
Secondary - Phonation
