Ch 5 Book Questions

Describe three functions of the larynx. *

1. Primary purpose of the larynx is to protect the lungs from the foreign body, whether an errant piece of food or one's own saliva. 2.

To what do the terms abduction and adduction refer? What muscles control tase actions?

Abduction: refers to opening, or outward (lateral) movement. Muscles is posterior cricoarytenoid. Adduction: refers to the inward (medial) or closing movement. Muscles are lateral cricoarytenoids, the transverse arytenoids, and the oblique arytenoid muscles.

Describe separately the general functions of the extrinsic laryngeal muscles.

Extrinsic muscle- Digastric: elevates hyoid (and move it anteriorly) Geniohyoid: draws tongue and hyoid bone forward Mylohyoid: elevates hyoid or depresses mandible Stylohyoid: elevates and retracts hyoid Thyrohyoid: depresses hyoid bone or elevates thyroid cartilage Sternohyoid: depresses hyoid bone Sternothyroid: depresses thyroid cartilage Omohyoid: depresses and retracts hyoid bone

Define glottis, subglottis, and supraglottis.

Glottis: when the vocal folds are abducted (open), the space that is formed between them Subglottis: the airway below the vocal folds Supraglottis: the airway above the vocal folds

Identify the supra- and infra hyoid muscles and their functions.

Infrahyoid muscles ("below" the hyoid) are sternohyoid (connecting the thyroid cartilage with the sternum), the sternohyoid (connecting the sternum with the hyoid bone), and the thyrohyoid muscle (connecting the thyroid cartilage with the hyoid bone). [ the omohyoif and inferior pharyngeal constrictor are also considered infrahyoid muscles, but they are not generally considered extrinsic laryngeal muscles ] Suprahyoid: muscles ("above" the hyoid) are stylohyoid, mylohyoid, geniohyoid, and digastric muscles, and sometimes the middle pharyngeal constrictor is also included as a supra hyoid muscle.

Describe separately the general functions of the intrinsic laryngeal muscles.

Intrinsic muscle- posterior cricoarytenoid: rotate vocal process of arytenoid laterally cricothyroid: pars recta, puls thyroid cartilage down; pars oblique, draws thyroid cartilage forward interarytenoids: oblique, pulls apex of arytenoids medially; transverse, glides arytenoids (and vocal folds) together (no rotation) lateral cricoarytenoids: rotate muscular process forward and inward (adducting vocal folds) thyroarytenoids (2) thryomusclaris: pulls arytenoids forward (releasing tension on thyrovocalis and vocal ligament to laden vocal folds). possibly also sphincter function working in conjunction with other adductor muscles. Thyrovocalis: tenses vocal folds

What types of movements are made by cricoarytenoid joints and what is the result of those movements?

Movements such as rocking- enables the vocal folds to abduct and adduct (predominant movement) gliding- enables the vocal folds to abduct and adduct rotating- ?

Describe the body-cover mechanical model of the vocal folds.

The body cover model groups the muscle and deep layer of lamina propria together, and the remainder of the lamina propria is grouped in turn with the epithelium as the cover layer.

What is the function of the cricothyroid joint, and what effect does movement of the joint have on the vocal folds? "

The function of the cricothyroid joint is to permit rotation such as when the cricothyroid muscle contracts, it rotates the thyroid cartilage downward and anteriorly. Since the cricothyroid joint is formed by the inner surface of the inferior horns of the thyroid cartilage and the side of the cricoid cartilage, the forward gliding motion of the thyroid cartilage may be responsible for up to 30% to 40% of potential elongation of the vocal folds and it contributes to vocal fold adduction.

Describe the three-layer mechanical model of the vocal folds.

The three layers are: epithelium and Reinke's space (referred to as the mucosa) the transition (vocal ligament) body (thyroarytenoid muscle)

Identify the three layers of the lamina propria and describe their composition.

Three layers are: superficial layer of the lamina propria- composed of loosely arranged elastin fibers and a cellular matrix. intermediate layer of the lamina propria- immediately below the superficial layer, is also composed of elastin fibers, but these are more densely distributed and interwoven and and organized to lie parallel to the free edge of the vocal folds. Deep layer of the lamina propria- is composed heavily of collagen fibers, which, like the elastin fibers of the intermediate layer, are tightly packed and lie parallel to the length of the vocal folds.

Identify the three paired and three unpaired laryngeal cartilages.

Three unpaired: cricoid, thyroid, and epiglottis Three paired: arytenoids, corniculate, and cuneiform (doesn't play a substantial role in voice production)

Define Reinke's space.

the consistency of the superficial layer is like gelatin which is often called Reinke's space. A few capillaries are found in Reinke's space, but no lymphatics. The low density of connective tissue fibers in Reinke's space results in a highly mobile layer of tissue.