04 - Anatomy & Physiology - Nerves? Flashcards
What are the two types of Laryngeal Muscles?
Extrinsic (Origin or Insertion point outside of the Larynx)
Intrinsic (Both Origin or Insertion points inside the Larynx)
What are the Extrinsic Muscles that ELEVATE the Larynx?
4
Digastric
Mylohyoid
Stylohyoid
Geneohyoid
What are the Extrinsic Muscles that DEPRESS the Larynx?
3
Thyrohyoid
Omohyoid
Sternohyoid
What are the Intrinsic Thyroid Muscles?
7
Cricothyroid
Posterior Crico-Arytenoid (PCA)
Lateral Crico-Arytenoid (LCA)
Transverse + Oblique Arytenoids
Aryepiglottic
Thryo-Arytenoid
Vocalis
What does the Cricothyroid connect?
Cricoid -> Thyroid
What does the PCA connect?
Cricoid -> Arytenoid
Posterior Crico-Arytenoid
What does the LCA connect?
Cricoid -> Arytenoid
Lateral Crico-Arytenoid
What do the Transverse + Oblique Arytenoids connect?
One Arytenoid to the other Arytenoid
What does the Aryepiglottic connect?
2
It is a continuation of the Oblique Arytenoid
It goes into the Aryepiglottic fold
What does the Thyro-Arytenoid connect?
Thyroid -> Arytenoid
What does the Vocalis connect?
Thyroid -> Arytenoids
Which Intrinsic Laryngeal muscles are innervated by the SUPERIOR Laryngeal Nerve?
Cricothyroid
Which Intrinsic Laryngeal muscles are innervated by the RECURRENT Laryngeal Nerve?
(6)
Posterior Crico-Arytenoid (PCA)
Lateral Crico-Arytenoid (LCA)
Transverse + Oblique Arytenoids
Aryepiglottic
Thryo-Arytenoid
Vocalis
What is the function of the Cricothyroid?
What does it do?
What kind of joint is it?
Changes pitch
Lengthens, tenses, and adducts
Tense
What is the function of the PCA?
ABDUCTS Vocal Folds
Posterior Crico-Arytenoid
What is the function of the LCA?
Adducts vocal folds
Lateral Crico-Arytenoid
What is the function of the Transverse + Oblique Arytenoids?
Adducts vocal folds
What is the function of the Aryepiglottic?
Adducts aryepiglottic folds
What is the function of the Thryo-Arytenoid?
Probably relaxes vocal folds
What is the function of the Vocalis?
Alters vocal fold in phonation
What do we call the membrane that connects the Hyoid + Thyroid Cartilages?
Thyro-Hyoid Membrane
What is the Quadrangular Membrane?
3
It covers the Thyroid and Arytenoid Cartilages all the way to the Epiglottis
It also covers the upper part of the Aryepiglottic folds
The inferior margin makes the Ventricular Folds (False Vocal Folds)
What is the name for the ligament that connects the Thyroid + Cricoid Cartilages?
Cricothyroid Ligament
What is the name for the ligament that connects the Epiglottis to the Thyroid Lamina?
Thyroepiglottic Ligament
What is the name for the ligament that connects the Epiglottis to the Hyoid Bone?
Hyoepiglottic Ligament
What is the Conus Elastics?
2
An elastic membrane that starts at the Cricoid Cartilage
It connects to the inner surface of the Thyroid Cartilage and the Vocal Processes (Arytenoids)
What does the Cricothyroid Joint increase the distance between?
(2)
Anterior Commissure (junction of the vocal folds)
Vocal Processes
What muscles are associated with the Cricothyroid Joint?
Vertical + Oblique Cricothyroids
What is the Cricoarytenoid Joint?
Connects the Cricoid with the base of the Arytenoid
What does the Cricoarytenoid Joint do?
4
Rotates
Slides
Tilts anteriorly + posteriorly
Helps tense + relax vocal folds
What muscles are associated with the Cricoarytenoid Joint?
5
PCA
LCA
Transverse + Oblique Arytenoids
Thyro-Arytenoid
Vocalis
What are the three folds in the Larynx?
Ary-Epiglottic Folds
False Vocal Folds (Ventricular/Vestibular Folds)
True Vocal Folds
What are the three REGIONS of the Larynx?
Supraglottal
Glottal
Subglottal
What are the two CAVITIES of the Larynx?
Laryngeal Vestibule (Between epiglottis + false vocal folds)
Laryngeal Ventricle (Between true + false vocal folds)
What do we call the disorder when a speaker uses their false vocal folds more than the true ones?
Ventricular Dysphonia
What are the three layers of the Vocal Folds?
Cover (loosely packed)
Transition Layer
Body (tightly packed)
What is in the Cover of the Vocal Folds?
2
Stratified Squamous Epithelium
Superficial Lamina Propria (LP) / Reinke’s Space
What is in the Transition Layer of the Vocal Folds?
2
Middle Lamina Propria (LP)
Deep Lamina Propria (LP)
What is in the Body of the Vocal Folds?
Vocalis
What is the Mucosal Wave?
2
The compliant cover interacting with the more stiff Basement Membrane Zone
The Transitional Layer balances this dichotomy
What innervates the Larynx?
2
Vagus Nerve (X)
Glossopharyngeal Nerve
The Vagus Nerve divides into 4 branches. Which are the three that supply the Larynx?
Pharyngeal Nerve
Superior Laryngeal Nerve (SLN)
Recurrent Laryngeal Nerve (RLN)
What are the two branches of the Superior Laryngeal Nerve (SLN)?
External Branch
Internal Branch
Where does the INTERNAL Branch of the Superior Laryngeal Nerve pass?
Through the Thyrohyoid membrane
Where does the EXTERNAL Branch of the Superior Laryngeal Nerve pass?
Inferiorly with the Superior Thyroid Vessels
What innervates the Cricothyroid Muscle?
The External Branch of the Superior Laryngeal Nerve (SLN)
What supplies most of the mucosa above the Glottis?
The Internal Branch of the Superior Laryngeal Nerve (SLN)
What are the three divisions of the Internal Branch of the Superior Laryngeal Nerve (SLN)?
First division
Middle division
Inferior division
What is another name for the Recurrent Laryngeal Nerve (RLN)?
Inferior Laryngeal Nerve (RLN)?
What is different about the two branches of the Recurrent Laryngeal Nerve (RLN)?
The right loop is shorter because the left has to go around the aorta
What is unique about the Cricothyroid?
It is the only intrinsic laryngeal muscle not supplied by the Recurrent Laryngeal Nerve (RLN)
What is unique about the Posterior Crico-Arytenoid (PCA)?
It is the only muscle that abducts
What are three possible voice pathologies associated with nerve damage?
(3)
Vocal Fold Paralysis
Monotoneness
Inability to increase loudness
What might be the effect of a lesion on the External Branch of the Superior Laryngeal Nerve (SLN)?
Trouble changing pitch due to malfunction of the Cricothyroid
Which branch of the Superior Laryngeal Nerve (SLN) is sensory?
The Internal Branch
What will a lesion on the Recurrent Laryngeal Nerve (RLN) cause?
(2)
Trouble with abduction and adduction
It will be more specific the further down the lesion is
What is Paralysis?
Complete loss of function
What is Paresis?
Partial loss of function
What is the Cover-Body Theory?
2
The cover of the vocal folds is lax and the body is dense creating a difference in the vibratory properties of each
This makes a vertical phase difference when vibrating = mucosal wave
What is the Myo-Elastic Aerodynamic Theory?
3
When air reaches the vocal folds, the velocity decreases and air pressure increases
The pressure overcomes the strength holding the VF together and they are blown apart.
This reduces subglottal pressure and the VF’s elasticity and the Bernoulli Effect cause the VF to adduct again
What is the Bernoulli Effect?
2
An increase in velocity is always accompanied by an increase in pressure
This creates areas of high and low pressure
What is the Vertical Phase Difference?
2
Vocal folds open from superior to inferior aspects
They close from inferior to superior
What is the Neurochronaxic Theory?
2
That every vibration of the vocal fold is cause by a muscle contraction
No accepted as a valid theory
How is vocal pitch modified?
By modifying the length, tension, and mass of the VF
What is the primary muscle that controls pitch?
Cricothyroid
What happens when the Cricothyroid contracts?
3
The distance increases between the thyroid and arytenoid cartilages
This increases the tension and length of the VF which reduces mass per unit
This causes the VF to vibrate at higher frequencies
What happens when the Thyroarytenoid contracts?
2
Relaxes the VF by reducing their length
This decreases the pitch
What are some other processes that affect pitch?
3
Increased subglottal pressure
Increased medial compression of the VF
Increased glottal airflow
What affects loudness?
3
Subglottal pressure
Medial compression of the VF (stay closed longer)
Duration, degree, + speed of VF closure
What increases subglottal pressure?
More air in the lungs creating a greater buildup
What affects vocal quality?
2
Glottal source
Resonance characteristics
(Not as well understood)
What creates breathiness?
Hoarseness?
Vocal strain?
Incomplete glottal closure
Aperiodicity or irregularities in the mucosal wave
Subglottal muscle tension and possible involvement of the false VF
