Lec 4 Phonation

Question 1

What is the Larynx?

Answer 1

The ‘voice box’. It is the cartilaginous structure housing the two bands of tissue we call the vocal folds.

Question 2

What is phonation?

Answer 2

Phonation refers to the process in which the silent airstream from the lungs is converted into audible acoustic energy.

Question 3

Where is the larynx found?

Answer 3

On top of the trachea

Question 4

What is the cricoid cartilage?

Answer 4

‘top most ring of the trachea. forms the connection between the trachea and the larynx.’

It is an unpaired bone.

Question 5

What is the thyroid cartilage?

Answer 5

V shaped shield
No connection at the back.
It is the largest of the laryngeal cartilages, articulating with the cricoid cartilage below by means of paired processes that lets it rock forward and backwards at that joint.

Question 6

What is the larynx made of?

Answer 6

3 unpaired and 3 paired cartilages bound by ligaments and lined with mucous membrane

Question 7

What is the arytenoid cartilages?

Answer 7

found on the high-backed upper surface of the cricoid cartilage, forming the posterior point of attachment for the vocal folds.

Question 8

What is the hyoid bone?

Answer 8

Hyoid bone, U-shaped bone situated at the root of the tongue in the front of the neck and between the lower jaw and the largest cartilage (thyroid) of the larynx, or voice box. (thyrohyoid membrane)

The primary function of the hyoid bone is to serve as an anchoring structure for the tongue

Question 9

What is the epiglottis?

Answer 9

It is a protective structure in that it will drop to cover the orifice of the larynx (the opening), during swalling

Question 10

What is the glottis?

Answer 10

Glottis is often used to refer to the vocal folds, it is a phonetic term, it refers to the space between the vocal folds. It affects the voice as it expands and contracts. You can see the trachea rings when the glottis is open.

Question 11

What is the distinction between extrinsic and intrinsic laryngeal muscles?

Answer 11

• Extrinsic - do not have attachment to the larynx, situated outside it.
• Intrinsic Laryngeal muscles. Pull the larynx down

Question 12

What can extrinsic muscles be divided into?

Answer 12

The extrinsic ones can be subdivided into laryngeal elevators (lift the larynx up) (suprahyoid muscles) and laryngeal depressors (infrahyoid muscles):

Question 13

What are the Intrinsic Laryngeal Muscles? p.189 - 193

Answer 13

The laryngeal muscles are a set of muscles in the anterior neck responsible for sound production. The intrinsic muscles of the larynx function to move the vocal cartilages and control tension.

• Abductor Muscle = opens the glottis.
  1. Called Cricoarytenoideus posterior. a paired muscle that covers most of the posterior part of both sides of the cricoid. It contracts, pulls on the sides of the arytenoids, turns it on their vertical axis and moves the vocal folds apart. It broadly abducts the vocal folds to permit greater air movement into and out of the lungs.
• Adductor Muscles = closes the glottis. All act on the arytenoids.
  1. Cricoarytenoideus lateralis - Connects the cricoid and the thyroid. It adducts (closes) the vocal folds and increases medial compression. On the sides of the cricoid cartillage
  2. Arytenoideus transversus - connects the left arytenoid with the right arytenoid. Contract pulls the arytenoids together over the cricoid cartilage moving the vocal folds together
  3. Arytenoideus obliquus - connects the top of one of the arytenoid with the bottom of the other arytenoid. a paired muscle. when contracting it will also pull the vocal folds together. has an ‘x’ shape. It also aids in pulling the epiglottis to cover the opening of the larynx as it also serves tight adduction.

Question 14

What is the Cricoarytenoideus ?

Answer 14

Abductor Muscle = opens the glottis.
1. Called Cricoarytenoideus posterior. a paired muscle that covers most of the posterior part of both sides of the cricoid. It contracts, pulls on the sides of the arytenoids, turns it on their vertical axis and moves the vocal folds apart. It broadly abducts the vocal folds to permit greater air movement into and out of the lungs.

Question 15

What is the Arytenoideus transversus ?

Answer 15

• Adductor Muscles = closes the glottis. All act on the arytenoids.

Arytenoideus transversus - connects the left arytenoid with the right arytenoid. Contract pulls the arytenoids together over the cricoid cartilage moving the vocal folds together

Question 16

What is the Arytenoideus obliquus -?

Answer 16

• Adductor Muscles = closes the glottis. All act on the arytenoids.

connects the top of one of the arytenoid with the bottom of the other arytenoid. a paired muscle. when contracting it will also pull the vocal folds together. has an ‘x’ shape. It also aids in pulling the epiglottis to cover the opening of the larynx as it also serves tight adduction.

Question 17

Explain the Myoelastic-aerodynamic theory.

Answer 17

Myoelastic = muscle elasticity
Aerodynamic = Aerodynamic means that the theory deals with the motion of air

The myoelastic theory states that when the vocal cords are brought together and breath pressure is applied to them, the cords remain closed until the pressure beneath them, the subglottic pressure, is sufficient to push them apart, allowing air to escape and reducing the pressure enough for the muscle tension recoil to pull the folds back together again. The pressure builds up once again until the cords are pushed apart, and the whole cycle keeps repeating itself. The rate at which the cords open and close, the number of cycles per second, determines the pitch of the phonation. The aerodynamic theory is based on the Bernoulli energy law in fluids

Question 18

Explain the Bernoulli effect

Answer 18

The Bernoulli effect states that given a constant volume flow of air or fluid, at a point of constriction there will be a decrease in air pressure perpendicular to the flow and an increase in velocity of the flow.