A&P Chapter 4 (everything but muscles)

Biological functions of the larynx

Airway protection, respiration, and phonation

Thyroid Cartilage Structure

Largest laryngeal (hyaline) cartilage. Includes superior notch and superior/inferior horns

Thyroid Cartilage Function

Protects vocal fold and tilts forward at the cricothyroid joint to increase vocal fold tension and raise pitch

Cricoid Cartilage Structure

Hyaline cartilage shaped like a signet ring. Has a narrow anterior arch and broad posterior lamina

Cricoid Cartilage Function

Provides foundation of larynx, maintains airway patency, and supports arytenoid movement

Arytenoid Cartilages Structure

Paired pyramidal cartilages located on the superior border of the cricoid lamina. Contains vocal and muscular processes.

Arytenoid Cartilages Function

Rotate and glide to adduct and abduct the vocal fold during phonation and breathing

Corniculate Cartilages Structure

Small paired elastic cartilages that sit in the apices of the arytenoids

Corniculate Cartilages Functions

Supports the aryepiglottic folds and laryngeal inlet

Cuneiform Cartilages Structure

Small paired elastic cartilages embedded within the aryepiglottic folds anterior to the corniculates

Cuneiform Cartilages Function

Provides rigidity and support to the aryepiglottic folds

Epiglottis structure

leaf-shaped elastic cartilage attached to the inner thyroid cartilage and hyoid region

Epiglottis Function

Helps protect airway during swallowing by directing food and liquid away from the laryngeal inlet

Hyoid Bone Structure

U-shaped bone superior to the larynx. Does not directly artoculate with other bones

Hyoid Bone Function

Provides attachment for tongue, laryngeal, and neck muscles. Assists in swallowing and laryngeal movement

Adduction

Movement that brings the vocal folds together for voicing

Abduction

Movement that separates the vocal folds for breathing

Pitch Increase

Occurs when the thyroid cartilage tilts forward, increasing vocal fold length and tension

Thyrohyoid Membrane Structure

Broad extrinsic membrane connecting the hyoid bone and thyroid cartilage

Thyrohyoid Membrane Function

Suspends the larynx from the hyoid bone and allows coordinated movement

Median Thyrohyoid Ligament Structure

Thickened midline portion of the thyroid membrane

Median Thyrohyoid Ligament Function

Provides central stabilization between the hyoid bone and thyroid cartilage

Lateral Thyrohyoid Ligaments Structure

Thickened lateral portion of the thyrohyoid membrane

Layeral Thyrohyoid Ligaments Function

Helps suspend and stabilize the larynx

Cricotracheal Ligament Structure

Connects the inferior border of the cricoid cartilage to the first tracheal ring

Cricotracheal Ligament Function

Anchors larynx to trachea

Conus Elasticus Structure

Fibroelastic membrane extending from the cricoid cartilage toward the vocal folds; superior border forms the vocal ligament

Conus Elasticus Function

Provides support for the vocal folds and contributes to phonation

Quadrangular Membrane Structure

Fibroelastic sheet extending from the epiglottis to the arytenoid cartilages

Quadrangualr Membrane Function

Forms structural support for the supraglottic larynx

Vestibular ligament

Inferior free edge of quadrangular membrane

Vestibular ligament Function

Forms the framework of the vestibular folds

Vocal ligament Sturcture

Superior free edge of the conus elasticus. Composed of intermediate and deep lamina propria

Thyroepiglottic Ligament Structure

Connects the petiole (stem) of the epiglottis to the inner surface of the thyroid cartilage near the thyroid angle.

Vocal Ligament Function

Provides strength and elasticity required for vocal fold vibration

Layngeal Vestibule

Space extending from the laryngeal inlet to the vestibular folds

Layngeal Ventricle

Space between the vestibular fold and the true vocal folds

Infraglottic Cavity

Right below the true vocal folds extending to the lower boarder of the cricoid cartilage

Epithelium

Most superficial vocal fold layer stratified squamous epithelium that protects underlying tissues

Superficial Lamina Propria

Loose, gel-like layer often called Reinke’s space. Essential for the mucosal wave

Intermediate Lamina Propria

Layer rich in elastic fibers. Contributes flexibility and stretch

Deep Lamina Propria

Layer rich in collagen fibers. provides tensile strength

Thyroarytenoid Muscle

Deepest layer of the vocal fold. Forms the body of the vocal fold

Cover

Epithelium + superficial lamina propria

Body

Thyroarytenoid/vocalis muscle

Collagen

Extra matrix protein that provides strength and resistance to stretching

Elastin

Extracellular matrix protein that provides flexibility and allowa recoil after stretching

Thyroepiglottic Ligament Function

Anchors the epiglottis to the thyroid cartilage and helps maintain epiglottic position

Hyoepiglottic Ligament Structure

Elastic ligament extending from the anterior surface of the epiglottis to the hyoid bone

Hyoepiglottic Ligament Function

Connects the epiglottis to the hyoid bone and contributes to epiglottic positioning during swallowing

Median Cricothyroid Ligament Structure

Thickened midline portion of the conus elasticus connecting the thyroid cartilage to the cricoid cartilage

Median Cricothyroid Ligament Function

Provides support between the thyroid and cricoid cartilages

Vocal Process Structure

Anterior projection of the arytenoid cartilage

Vocal Process Function

Attachment point for the vocal ligament

Muscular Process Structure

Lateral projection of the arytenoid cartilage

Muscular Process Function

Attachment point for intrinsic laryngeal muscles

Laryngeal Vestibule Boundaries

Extends from the laryngeal inlet superiorly to the vestibular folds inferiorly

Laryngeal Ventricle Boundaries

Located between the vestibular folds superiorly and true vocal folds inferiorly