Lesson 04-01: Intrinsic Muscles of the Larynx

Cricoid Cartilage

lowest and most stable part of the larynx - shaped something like a signet ring and is mounted on the top of the last ring of the trachea.

wide part is toward the back

Facets for Arytenoids

on both sides - serves to hold the thyroid in place.

also has a pair on top which holds the next part we install

Arytenoid Cartilage

pyramid shaped structures that form anchors for the vocal folds

Corniculate Cartilage

horn like cartilage - behave as part of the arytenoids with no real independent movement

Vocal Process

holds one end of each vocal fold

Muscular Process

holds one end of the muscle pair that acts in concert with the folds

Thyroid Cartilage

largest part of the laryngeal cartilages, articulating with the cricoid cartilage blow by means of paired processes that let it rock forward and backward at the joint

Inferior Horns (inferior cornua)

grasp the side of facers of the cricoid

Superior Horn

holds up the hyoid bone

Lamina

each side

Notch

in front is where the vocal folds are attached

Pars Recta

runs more or less vertically - straight part

Pars Oblique

runs more toward the posterior of the thyroid cartilage - slanted part

Thyrovocalis Muscles

the inner pair and are the main tensor folds

contract - the folds become tense and ready to vibrate, and the arytenoid cartilages rotate inward

vocal folds

Thyromuscularis Muscles

oppose the thyrovocalis; when the thyromuscularis is contracted by itself, it rotates the arytenoid outward, leaving the folds more relaxed. The thyromuscularis is thus considered to be a relaxer for the folds.

originate from the notch of the thyroid cartilage and run to the muscular process of the arytenoid cartilages.

Abductt the fold

gliding outward serves to open

Adduct the folds

gliding inward (medially) serves to close

Arytenoids

rock forward and back on the facets of the cricoid; this action serves mainly for fine adjustments.

Glottis

Opening between vocal folds

Posterior Cricoarytenoid Muscles

are the only laryngeal muscles that act to exclusively ABduct or pull the folds apart. They also help in rocking the arytenoids back and outward.

Lateral Cricoarytenoid Muscles

ADduct (bring together) the folds, but they are not the only muscles of adduction.

Transverse Interarytenoid Muscle

run horizontally between the two arytenoid cartilages

Oblique Interarytenoids

runs from the posterior process of one arytenoid to the apex of the other.

Triticial Cartilages

create a flexible joint from the hyoid to the superior horns of the thyroid cartilage.

Greater Cornua

long set of two horns that project posteriorly from the hyoid bone

Corpus

large central portion of the uterus

Lesser Cornua

small set of horns that project superiorly from the hyoid bone