Cartilages of the Larynx - Speech Science

cricoid cartilage: means; importance; location

- "signet ring" - foundation of the larynx - forms the uppermost ring of the trachea - inferior to the thyroid

larynx

- anterior neck region - superior to trachea - suspended from the hyoid bone

cricothyroid

- articulation between the inferior horn of the thyroid cartilage and the cricoid cartilage - involved in Fundamental Frequency regulation by elongating and shortening vocal folds - joint makes cartilages flexible; so they can be rotated

What are the paired cartilages of the larynx?

- arytenoids - corniculates - cuneiforms

thyroid cartilage

- largest cartilage of the larynx - formed by two laminae (plates of cartilage) that are fused at the front - this forms the thyroid notch -projections: superior horns and the inferior horns

Superior horns of thyroid cartilage

- longer projections - extend upward and connect by ligaments to the hyoid bone

aryepiglottic fold

- most superior of the folds - run from the sides of the epiglottis to the apex of each arytenoid cartilage - contract pull epiglottis backward and to close the entrance of the larynx during swallowing

corniculate cartilages

- paired - located on the superior part(apex) of the arytenoids - small nodules

Arytenoid cartilages: where, shape, parts?

- paired - rest on cricoid cartilage - pyramid (triangular) in shape - Two parts: muscular process, vocal process

muscular process

- part of the arytenoid cartilage - intrinsic muscles of larynx attached - projects laterally and posteriorly

vocal process

- part of the arytenoid cartilage - vocal ligament (part of the vocal folds) attache here - projects anteriorly toward the thyroid cartilage

Function of the cuneiform cartilages?

- really no function if some of us don't even have them

inferior horns of the thyroid cartilage

- shorter projections - extend downward and articulate with the sides of the cricoid cartilage

hyoid bone

- small, U-shaped bone that forms the attachment for the tongue - consists of the body in front, and the major horns forming the long sides of the U - minor horns protrude from each major horn

Why is the thyroid notch more prominent in men than in women?

- the angle at which the laminae join is more acute in men than in women - around 80 degrees in men - around 90 degrees (so broader) in women

Epiglottis

- unpaired cartilage - shaped like a leaf - attached to the inner surface/angle of the thyroid cartilage to the base of the tongue - protection

What are the two joints of the larynx?

-Cricoarytenoid joint - cricothyroid joint

What are the unpaired cartilages of the larynx?

-cricoid - epiglottis - thyroid

cuneiform cartilages

-paired - located on the fold between the arytenoid and epiglottis - extremely tiny; microscopic - embedded within the aryepiglottic folds

vestigial

-refers to cuneiform cartilages -don't really serve a purpose in human beings since we have evolved - may serve a purpose in other animals

thyroid notch

-v shaped notch on the thyroid cartilage - more prominent in men than in women - aka "adam's apple"

What are the two functions of the arytenoid cartilages?

1. Abduction 2. Adduction

What are the functions of the corniculate cartilages?

1. Better attachment: to muscles that can help with opening and closing of the vocal folds 2. extension of arytenoids

Four primary functions of the larynx?

1. Protection 2. Air Pressure 3. Swallowing 4. Airflow

What are the two functions of the thyroid cartilage?

1. Protective: protects sensitive structures within larynx 2. Pitch: the joint (cricothyroid) helps to change frequency and therefore the pitch

What is the main function of the epiglottis?

Protection: Folds over and closes the trachea (laryngeal) opening; assists in swallowing - During swallowing, folds downwards over the entrance to the larynx and acts as a bridge to direct food and liquids to the esophagus

protection

airway; protection from foreign bodies into the airway

air pressure

builds up subglottal airpressure; i.e. when heavy lifting, excreting waste, birthing children

puberphonia

continue to use pre-puberscent high pitched voice

Which cartilages may not even be present in all humans?*

cuneiform cartilages

swallowing

helps in swallowing; when you swallow the larynx raises

hyothyroid membrane

membrane that connects the hyoid bone and thyroid cartilage

airflow

monitors the airflow in and out of lungs

What is the function of the larynx when it is not doing its primary functions?

sound generator

Phonation

sound produced by setting the vocal folds into vibration using the exhaled air (at the laryngeal level)

Where are the vocal folds found?

they are attached to the inner surface of the thyroid, just below the thyroid notch at the anterior commissure

adduction*

vocal folds brought together

abduction*

vocal folds separate