A&P - Exam 2

Phonation

• voicing - product of the vibration of the vocal folds

• occurs within the larynx

What happens to the vocal folds when you produce voiceless phonation?

they abduct

What happens to the vocal folds when you produce voiced sounds?

they adduct

How are voicless sounds created?

by turbulence of airflow

Larynx structure

• musculocartilaginous structure: muscles and cartilages

• length: male 44mm, female 36mm

• suspended from the hyoid bone

• sits on the top of the trachea

• adjacent tp C4-C6

• vocal fold mobility provided by: IA, TA, LCA, PCA, CT

What is the innervation for the larynx?

CN X; vagus nerve

Larynx function

1) primary/biological: protection of the lower air way; lifting, coughing, defecation, birth

2) speech realted: phonation - vibration of the vocal folds/sound source for voiced speech, and determination of voiced/voicless sounds

What is F?

hyoid bone

What is A?

epiglottis

What is B?

thyroid cartilage with the thyrohyoid membrane

What is E?

corniculate cartilage

What is D?

arytenoid cartilage

What is C?

cricoid cartilage

What is the long tube at the end of the larynx?

trachea

What are the 3 paired cartilages? (CAC)

• corniculate

• arytenoid

• cuneiform

Corniculate cartilage

sits on the superior surface of each arytenoid cartilage

• posterior part of the aryepliglottic folds

Cuneiform cartilage

• rod shaped, hidden in the aryepiglottic folds, extremely tiny

• said to help provide structural integrity for membranous tissue

Arytenoid cartilage

• sits on the superior surface of the posterior of the cricoid cartilage

• forms the posterior point of attachment of the vocal folds

What is the blue linging?

thyroid cartilage

What is the inner blue lining?

cricoid cartilage

What are the yellow lines?

vocal folds

Thyroid cartilage

unpaired; the largest cartilage of the larynx shield-shaped

• two “rectangular” laminae: anterior surface left/right; fused anteriorly in the midline

• thyroid notch

• laryngeal prominence and angle: “adams apple”

• oblique line

• 4 horns (2 superior and 2 inferior)

Connections through the horns (thyroid cartilage)

• connections between the thyroid and hyoid bone, and cricoid cartilage

• superior horns articulate with the hyoid bone through lateral thyrohyoid ligaments

• inferior horns articulate with the cricoid cartilage at the ‘facet for the thyroid’ forming the cricothyroid joint

  • the tyroid tilts/rocks forward and backward at this joint changing the VF length/tension

The medical aspect of the anterior portion of the thyroid cartilage is called

thyroid notch

The cartilage located below the thyroid notch is called

thyroid prominence

Which of the flowwing is the name of the largest, shield-shaped cartilage that protects and supports most of the laryngeal wall?

• hyoid

• cricoid

• thyroid

• arytenoid

• cuneiform

thyroid

The vocal folds are anteriorly attached to what?

inner surface of the anterior part of the thyroid cartilage, just below the notch

The vocal folds are posteriorly attached to what?

arytenoid cartilages (vocal process)

Cricoid cartilage

• looks like a signet ring seen from the side

• sits above the top of the 1st tracheal ring

• the posterior portion arches up

• two important ‘articulation facets’ on each side: total of 4

Cricothyroid joint at the inferior facets:

used for articulation with the thyroid cartilage’s inferior horns

Cricoarytenoid joint at the superior facets:

used for articulation with the arytenoids

Cricothyroid joint (2 joints)

• joint between the lower horns of the thyroid and the lower facet (lateral) of the cricoid

Motion at the cricothyroid joint

• rotationof the cricoid and the thyroid

• both cartilages rotate some

Impact of motion on the vocal folds (cricothyroid joints)

• contraction of muscles: lengthen/tense the vocal folds

• relaxation of muscles: allow vocal folds to return to rest length and tension

Cricothyroid muscle (CT)

affects vocal pitch

Epiglottis

leaf shaped cartilage

• arises from inner surface of the angle of the thyroid cartilage just below the notch

• protective: cover the opening of the larynx during swallowing

• the entire larynx is pulled superiorly, and the epiglottis bends inferiorly to cover and seal laryngeal inlet

• keeps food out of lower respiratory tract (trachea and below)

What is the epiglottis connected to?

thyroid, hyoid bone, and tongue

1.) thyroepiglottic ligament

2.) hyoepiglottic ligament

3.) glossoepiglottic ligaments

Epiglottis meets the tongue root

at the top area, the epiglottis is attached to the root of the tongue by 3 glosso-epiglottic folds

• 1 median glosso-epiglottic fold

• 2 lateral glosso-epigottic folds

Arytenoid cartilage (paired laryngeal cartilage)

paired pyramidal shaped cartilages, on top of high-backed surface of the cricoid cartilage

• form synovial joints with cricoid cartilage: anterior/posterior cricoarytenoid ligaments

• two processes: vocal process and muscular process

• the VFs are attached to vocal process, any movement in the arytenoid will change the folds, shape, tension and relationship to each other thereby affecting phonation

• forms the posterior point of attachment of the VFs

Gliding

opens of closes the cartilaginous glottis

Rocking

opens or closes the membranous glottis

What is 1?

corniculate cartilage

What is 3?

apex

What is 4?

muscular process

What is 5?

vocal process

What is 7?

superior facet

What is 8?

inferior facet

Intrinsic laryngeal muscles

• muscles that connect the larynx to itself

• origin and insertion are both on laryngeal cartilages

• all are paired; subtle control of the glottis: adduct or abduct

• (IA, TA, LCA), (PCA), (CT) - tenses

Extrinsic laryngeal muscles

• they attach to a site within the larynx (or hyoid bone) and to a site outside of the larynx (jaw)

• much larger and longer than intrinsic muscles: total of 8 muscles

Function

to move the entire larynx by elevating or depressing it; important for positioning and supporting the larynx when swallowing

Posterior cricoarytenoid (PCA) origin:

posterior cricoid lamina (left/right)

Posterior cricoarytenoid (PCA) insertion:

posterior aspect of the muscular process of the arytenoid

Posterior cricoarytenoid (PCA) function:

pulls the muscular process of the arytenoid posteriorly to rock arytenoid laterally; abducts the vocal folds (only abductor)

Posterior cricoarytenoid (PCA) motor supply:

CN X (vagus nerve); recurrent laryngeal nerve branch

Lateral cricoarytenoid (LCA) origin:

superolateral surface of the cricoid cartilage

Lateral cricoarytenoid (LCA) insertion:

muscular processes of the arytenoid

Lateral cricoarytenoid (LCA) function:

rotates the muscluar process of the arytenoids anteriorly, rocking the vocal process medially and inferiorly; adduction of the membranous vocal fold

Lateral cricoarytenoid (LCA) motor supply:

CN X; recurrent laryngeal nerve branch

Interaryteniod oblique muscle (IA) origin:

posterior base of muscular process of arytenoid

Interaryteniod oblique muscle (IA) insertion:

apex of opposite arytenoid

• also pulls apex medially and rocks arytenoid down and in

Interaryteniod oblique muscle (IA) function:

pulls two arytenoids closer to approximate the cartilaginous vocal folds (assuction of posterior glottis)

Interaryteniod oblique muscle (IA) motor supply:

CN X; recurrent laryngeal nerve branch

Interarytenoid transverse muscle (IA) origin:

lateral margin of posterior arytenoid

Interarytenoid transverse muscle (IA) insertion:

lateral margin of opposite posterior arytenoid

Interarytenoid transverse muscle (IA) function:

pulls two arytenoids closer to approximate the cartilaginous vocal folds (adduction of posterior glottis)

Interarytenoid transverse muscle (IA) motor supply:

CN X; recurrent laryngeal nerve branch

Thyroarytenoid (TA) origin:

inner surface of the anterior thyroid cartilage

Thyroarytenoid (TA) insertion:

arytenoid

1) lateral surface of vocal process

2) base and muscular process

Thyroarytenoid (TA) motor supply:

CN X; recurrent laryngeal nerve branch

The inner layer of the thyroarytenoid (TA) is what?

thyrovocalis muscle

The outer layer of the thyroarytenoid (TA) is what?

thyromuscularis muscle

Cricothyroid (CT) origin:

anterolateral surfaces of arch of cricoid cartilage

Cricothyroid (CT) insertion:

lateral inferior boarder of the thyroid lamina cartilage and anterior surface of the inferior horn

• two parts: pars recta (1st), pars oblique (2nd)

Cricothyroid (CT) function:

upon contraction, CT pulls the thyroid and cricoid together, lengthening, and tensing the vocal folds

Cricothyroid (CT) motor supply:

CN X; external branch of superior laryngeal nerve

What joint does the cricothyroid muscle cross?

cricothyroid joint

Changing fundamental frequency means

• changing tension by changing the interal stiffness of the vocal folds

• changing the length of the vocal folds

• changing the amount of mass in vibration

IA: adductor

inter-arytenoid muscles; transverse fibers & oblique fibers; closes cartilaginous portion

TA: adductor

thyro-arytenoid; thyrovocalis (tenses and shortens) & thyromuscularis (shortens and relaxes)

LCA: addcutor

lateral crico-arytenoid; closes membranous glottis

PCA: abdutor

posterior crico-arytenoid; posterior crocoid lamina

CT: creates tension but doesnt abduct or adduct

cricothyroid; brings anterior parts together; lengthens and stetches the vocal folds; external branch of the superior laryngeal nerve

What is 1?

poaterior cricothyroid

What is 2?

inner arytenoid (oblique and transverse)

What is 3?

cricoid cartilage

What is 4?

cricothyroid

What is 5?

thyromuscularis

What is 6?

thyrovocalis

What is 7?

muscular process

What is 8?

vocal process

What is 9?

vocal ligaments

Hyo-epiglottic is the linkage of what?

hyoid bone and epiglottis

Thyro-epiglottis is the linkage of what?

thyroid cartilage and epiglottis

Median and lateral thyro-hyoid is the linakge of what?

throid cartilage and hyoid bone

Crico-thyroid is the linkage of what?

cricoid and thyroid cartilage

Crico-tracheal is the linkage of what?

cricoid and tracheal cartilage

Thyro-arytenoid/vocal ligament is the linkage of what?

thyroid cartilage and arytenoid

Cranial nerves

bundles of sensory or motor fibers

• always paired: 12 pairs

• branch off from the brainstem

Sensory nerves

carry impulses from sensory receptors; ascending/afferent

Motor nerves

contract mucscles or innervate glands; descending/efferent