Phonation: Structures and Processes Flashcards
Biological functions of the larynx
- closure of the trachea to stop food and other substances from entering lungs
- Production of cough reflex to expel foreign substances that enter trachea
- closure of vocal folds to build subglottic pressure necessary for physcal tasks such as excretion and lifting heavy items
Housed in the larynx is the ___ ___
vocal folds
- which vibrate to produce sound for voice
vocal folds move toward the midline when they
adduct
Vocal folds move away from the midline when they
abduct
When a person is breathing quietly, vocal folds are
abducted
the muscles of the tongue and various muscles of the mandible, skull and larynx are attached to the
HYOID BONE
The laryns is suspended from the ___ ___
HYOID BONE!
which floats under the mandible, or lower jaw
A leaf-shaped peice of cartilage medial to the thyroid cartilage and hyoid bone that functions as a protective structure
EPIGLOTTIS!
- the epiglottis drops to cover the orifice of the larynx during swallowing
Key cartilages of the larynx
- THYROID
- CRICOID
- ARYTENOID
The largest laryngeal cartilage that protects and forms the anterior and lateral walls of the larynx
Thyroid cartilage
The anterior surface of the thyroid cartilage is composed of two _______ that meet at the midline to form the _______ _____.
laminae or plates; thyroid angle
The superior point of the thyroid angle commonly called the “Adam’s apple”
Thyroid notch
The thyroid cartilage is open ________ and has two pairs of horns, known as the _______
posteriorly; cornu
The pair of horns (cornu) that extend upward to meet with the hyoid bone is called
Superior Cornua
The pair of horns (cornu) that extend downward to meet with the cricoid cartilage is called
Inferior Cornua
CRICOID CARTILAGE
- some view as uppermost tracheal ring
- linked with the thryoid and arytenoid cartilages
- completely surrounds the trachea
- larger in the back than in the front
Small pyramid-shaped cartilages connected to the superior posterior cricoid through the cricoarytenoid joint
- permits sliding and circular movements
Arytenoid cartilages
laryngeal cartilage that many intrinsic laryngeal muscles connect to
Arytenoid cartilages; intrinsic laryngeal muscles connect to the arytenoids at teh two processes the vocal process and the muscular process.
CORNICULATE CARTILAGES
- small cone-shaped cartilages that sit on the apex of the arytenoids
- they assist in reducing the laryngeal opening during swallowing
tiny cone-shaped cartilages located under the mucous membrane that covers the aryepiglottic folds
they stiffen or tense the aryepiglottic folds
Cuneiform cartilages
Intrinsic Laryngeal Muscles of the Larynx are
- thyroarytenoid (X)
- vibrates and produces sound; has two parts internal (vocalis; VF) and external (thyromuscularis)
- lateral cricoarytenoid (X)
- adducts VFs; increases medial compression
- transverse arytenoid (X)
- adducts VFs
- oblique arytenoid (X)
- pulls apex of arytenoids in a medial direction
- cricothyroid (X)
- lengthens and tenses VFs
- posterior cricoarytenoid (X)
- abducts VFs
THYROARYTENOID MUSCLES
- paired
- attached to the thyroid and arytenoid cartilages
- divided into two muscle masses:
- the internal thyroarytenoid ( vocalis muscle/vocal folds )
- the external thyroarytenoid ( thyromuscularis muscle)
The primary portion of the thyroarytenoid muscle that vibrates and produces sound
Vocalis muscle or Vocal folds
Muscle lateral to the vocalis that aids in vocal fold adduction when contracted
Thyromuscularis (external thyroarytenoid)
Adductor laryngeal muscles
- lateral cricoarytenoid
- transverse arytenoid
- oblique arytenoid
- these muscles act to bring the VF’s together
- VF adduction is supported when the oblique and transverse arytenoid muscles contract and pull the arytenoids closer together
- lateral cricoarytenoid increases medial compression of the VF’s by rotating the arytenoids medially
The intrinsic laryngeal muscle attached to the cricoid and thyroid cartilages
- lengthens and tenses the vocal folds resulting in pitch change
Cricothyroid muscle
EXTRINSIC
LARYNGEAL
MUSCLES
- primary function is to support larynx and fix its position
- extrinsic laryngeal muscles have -
- one attachment to a structure within the larynx and
- one attachment to structure outside the larynx
- all extrinsic muscles are attached to hyoid bone and lower or raise the position of the larynx within the neck
- Innervations are generally provided by :
- CN V (trigeminal)
- CN VII (Facial)
- CN X (Vagus)
- CN XII (Hypoglossal)
- portions of cervial spinal nerves C1-C3
- Two kinds : elevators and depressors
Elevators
(Suprahyoid muscles)
- attaches above the hyoid bone
- primary function: elevation of the larynx
- suprahyoid muscles are:
- digastric (V, VII)
- geniohyoid (XII, C1)
- mylohyoid (V)
- stylohyoid (VII)
- hyoglossus (XII)
- genioglossus (XII)
Depressors
(Infrahyoid muscles)
- attach below the hyoid bone
- Primary function: depression of the larynx
- Infrahyoid muscles are :
- Thyrohyoid (XII, C1)
- Omohyoid (C1-C3)
- Sternothyroid (C1-C3)
- Sternohyoid (C1-C3)
3 LAYERS OF THE VOCAL FOLDS
- Epithelium (outer cover)
-
Lamina Propria (middle layer) -
- has 3 layers of its own: superficial, intermediate, and deep
- Vocalis Muscle (body) - provides stability and mass to the vocal fold
ARYEPIGLOTTIC FOLDS
- composed of ring of connective tissue and muscle extending from tips of the arytenoids to the epiglottis
- Separates the laryngeal vestibule from the pharynx and helps preserve the airway
VENTRICULAR (FALSE) VOCAL FOLDS
- vibrate only at very low fundamental frequencies and usually not during normal or typical phonation
- compresses during activities such as coughing and lifting heavy items
