Larynx Anatomy

Epiglottis

protective cartilage flap that prevents food and water from getting into the respiratory tract

Thyroid

largest primary cartilage support structure that protects the vocal cords, rocks back and forth at cricothyroid joint, articulates with hyoid bone

cricoid

last cartilage ring that anchors muscles and ligaments, also produces voice by controlling vocal cords

arytenoid

paired cartilage that produces sound and regulates airflow

corniculate

paired cartilage on top of arytenoids that prop up and support the aryepiglottic folds, they also help assist arytenoid movement

vocal folds

produces voice

hyoid bone

provides support and movement for larynx, not directly connected to other bones (connected via ligaments and muscles) attached to tongue and 23 muscles

larynx functions

breathing, speaking, swallowing

cuneiform cartilage

located within the aryepiglottic folds to strengthen and support them

cricothyroid muscle

controls pitch by lengthening and shortening vocal folds

lengthening and shortening of vocal cords

the cricothyroid muscle contracts and lengthens the vocal cords to produce high pitch sounds and it shortens and relaxes to produce low pitch sounds

cricothyroid joint

synovial joint: rocking, gliding, rotation; creates changes in pitch

cricoarytenoid joint

synovial joint: rocking, gliding, rotation. Adduction of vocal folds, changes in vocal cord length

Adductor muscles

Lateral cricoarytenoid, transverse arytenoid, oblique arytenoid

lateral cricoarytenoid muscle

adductor, pulls arytenoid cartilages together (vocal folds come together)

transverse arytenoid

adductor, pulls arytenoid cartilages together (vocal folds come together)

oblique arytenoid

adductor, pulls arytenoid cartilages together (vocal folds come together)

posterior cricoarytenoid muscles

abductor, opens airway for breathing, coughing

glottal tensors

cricothyroid muscles, pars recta, pars oblique, thyrovocalis (medial thyroarytenoid) muscles

cricothyroid muscles

glottal tensor, rocks thyroid cartilage forward to tense and lengthen vocal cords to change pitch

thyromuscularis (thyroid muscle)

relaxers

Auxillary musculature

thyroarytenoid, superior thyroarytenoid, aryepiglotticus, thyroepiglotticus

hyoid and laryngeal elevators

muscles that lift the hyoid bone and larynx and thyrohyoid muscle (swallowing)

hyoid and laryngeal depressors

muscles that pull the hyoid bone and larynx down (breathing and swallowing)

vocal folds

bands of mucous membranes, connective tissue, thyrovocalis muscle

The epiglottis is highly connected

to the thyroid, hyoid bone, and tongue

cartilage at front of vocal folds

thyroid cartilage

cartilage at back of vocal folds

arytenoid cartilage

quiet breathing glottis size

8 mm

forced respiration glottis size

16mm

larygeneal muscle group needed for inhalation 

adductors, respiratory muscles 

coughing

caused by irritation on respiratory tract tissue

cough is triggered by

vagus nerve

muscles used for coughing

abductors, adductors, tensors, elevators 

when our cores tighten our vocal folds

adduct

valsalva maneuver

popping ears

swallowing process

larynx elevates, epiglottis folds down and covers larynx, aryepiglottic folds tense and adduct the vocal folds 

vibration

movement possible by elasticity, stiffness, and inertia

elasticity

return to original state after being displaced

stiffness 

strength of elasticity after being displaced 

inertia

object in motion stays in motion

pitch

tone produced by vibration ex. guitar

Bernoulli effect 

at a point of constriction with an increase in velocity there is a decrease in pressure which creates a suction, this cycle repeats

Bernoulli effect in relation to vocal folds

As air from the lungs travels through the narrow glottis, its speed increases, creating a drop in pressure. This low-pressure area pulls the vocal folds together, this cycle repeats, opens from posterior to anterior

frequency Hz

how many repetitive cycles of vibration per second

intensity dB

loudness and amplitude of the waveform 

sustained phonation

holding the vocal folds in the air stream for vibration

simultaneous vocal attack

breath and vocal fold vibration stops at the same time

breathy vocal attack

airflow comes before closing the vocal folds 

glottal attack

adduction of folds comes before respiration ex. uh oh

vocal register

a mode of vocal fold vibration

modal voice (register) 

pattern of phonation used in daily conversation 

glottal fry

pulse register, low in pitch, rough sounding

falsetto

highest register of phonation

whispering

non phonatory, no vibration despite tension

what effects pitch?

vocal fold mass, length, tension, elastic qualities

muscles associated with pitch

cricothyroid: stretch and thins vocal folds, thyrovocalis