Laryngeal Anatomy and Physiology Lecture Review

Flashcards covering key vocabulary related to laryngeal anatomy, muscle functions, vocal fold layers, phonation theories, and laryngeal physiology from the lecture notes.

Paired Laryngeal Cartilages

Arytenoid, Corniculate, and Cuneiform cartilages.

Unpaired Laryngeal Cartilages

Thyroid and Cricoid cartilages.

Extrinsic Laryngeal Muscles

Muscles that hold the laryngeal mechanism in place, elevating, and depressing the larynx within the vocal tract.

Suprahyoid Muscles

Extrinsic laryngeal muscles located above the hyoid bone that elevate the larynx (e.g., Mylohyoid, Digastric).

Infrahyoid Muscles

Extrinsic laryngeal muscles located below the hyoid bone that depress the larynx.

Thyroarytenoid Muscle (Vocalis Muscle)

An intrinsic laryngeal muscle that shortens the vocal folds upon contraction and forms the deepest layer of the vocal fold.

Posterior Cricoarytenoid (PCA)

The only intrinsic laryngeal muscle responsible for abducting (opening) the vocal folds.

Lateral Cricoarytenoid (LCA)

An intrinsic laryngeal muscle involved in initiating adduction (closing) of the vocal folds.

Interarytenoids (Transverse and Oblique)

Intrinsic laryngeal muscles that tighten the vocal folds for complete adduction, ensuring full closure and no gap.

Cricothyroid Muscle (CT)

An intrinsic laryngeal muscle responsible for changing pitch by elongating, tensing, and condensing the vocal folds.

Thyrohyoid Membrane

An extrinsic laryngeal membrane connecting the thyroid cartilage and the hyoid bone.

Cricotracheal Membrane

An extrinsic laryngeal membrane connecting the cricoid cartilage and the trachea, making them continuous.

Intrinsic Laryngeal Membranes

Membranes connecting each laryngeal cartilage together within the larynx, making it a continuous structure and controlling unified movement.

Aryepiglottic Fold

A fold extending bilaterally between the arytenoid cartilages and the epiglottis, containing cuneiform and corniculate cartilages.

Function of Cuneiform and Corniculate Cartilages

Embedded in the aryepiglottic fold, they provide structural support to prevent the pliable fold from collapsing inward during inspiration or swallowing.

Glottis

The space between the true vocal folds at their level.

Laryngeal Cavities

Anatomical divisions including the supraglottis (above glottis), glottis (at vocal fold level), and subglottis (below glottis, extending to trachea).

Ventricular Vocal Folds (False Vocal Folds)

Located slightly superior and lateral to true vocal folds, they protect the airway and true vocal folds from pathogens during swallowing.

True Vocal Fold Layers

Composed of five distinct layers: Epithelium, Superficial Lamina Propria (Reinke's space), Intermediate Lamina Propria, Deep Lamina Propria, and Vocalis Muscle.

Reinke's Space

The superficial layer of the lamina propria, consisting of loose connective tissue that allows free movement but is prone to fluid accumulation (Reinke's edema).

Density Gradient of True Vocal Folds

The progressive increase in density from the superficial layers (epithelium, superficial lamina propria) to the deepest layer (vocalis muscle), crucial for enabling vocal fold vibration.

Cover-Body Model of Vocal Folds (Three-Zone Model)

A biomechanical model categorizing the five layers into three functional zones: Cover (epithelium + superficial lamina propria), Transition (intermediate + deep lamina propria), and Body (vocalis muscle), whose contrasting densities control vibration.

Adduction (Vocal Folds)

The process of closing the true vocal folds.

Abduction (Vocal Folds)

The process of opening the true vocal folds.

Whispering (Laryngeal Mechanics)

A form of voice production that involves pressing the anterior portion of the vocal folds without full closure, leading to increased stress on laryngeal muscles and tissues.

Phonation

The physiological process of producing sound through the rapid vibration of the true vocal folds.

Myoelastic Aerodynamic Theory

A model explaining vocal fold vibration as a result of interaction between muscle (myo) contraction, elastic recoil of the vocal folds, and aerodynamic (airflow) forces (subglottal pressure and Bernoulli effect).

Subglottal Pressure

The air pressure built up beneath the adducted vocal folds, which eventually displaces and opens them during phonation.

Bernoulli Effect (in Phonation)

The aerodynamic principle where a drop in pressure occurs within the glottis as high-velocity air passes through the narrowed opening, contributing to the vocal folds' elastic recoil and closure.

Glottal Cycle

One complete vibration of the vocal folds, characterized by movement from closed to opened and back to closed, with the opening phase typically longer than the closing phase.

Pitch Change Mechanism

Primarily controlled by changing the tension and length of the vocal folds; increased tension and length lead to higher pitch and frequency.

Modal Register

The habitual or natural speaking voice frequency, characterized by consistent vocal fold vibration.

Pulse Register (Glottal Fry)

A low-frequency vocal register characterized by short, compact vocal fold vibrations, often perceived as a creaky voice.

Falsetto (Loft Register)

A high-frequency vocal register produced by stretching the vocal folds to their maximum length and tension.

Loudness Change Mechanism

Primarily achieved by increasing subglottal pressure, resulting in greater amplitude of vocal fold vibration.

Superior Thyroid Artery

A major arterial supply for the larynx, pharynx, upper esophagus, and thyroid gland.

Ascending Pharyngeal Artery

A major arterial supply for the lower pharynx and larynx.

Recurrent Laryngeal Nerve (RLN)

A branch of the Vagus nerve (CN X) providing motor control to all intrinsic laryngeal muscles EXCEPT the cricothyroid. It has a circuitous path around the aorta.

Superior Laryngeal Nerve (SLN)

A branch of the Vagus nerve (CN X) with two branches: an internal (sensory) and an external (motor control for the cricothyroid muscle).

Laryngeal Development

Changes from infancy (C3/C4 location, 400-600 Hz fundamental frequency) to adulthood, including laryngeal descent, vocal fold lengthening, and influence of sex hormones.

Laryngeal Aging (Presbylaryngis)

Structural changes in the larynx with age, such as muscle atrophy, edema, and demyelination of nerves, leading to acoustic changes and increased fatigue.

Laryngeal Reflexes

Involuntary and protective actions occurring at the level of the larynx in response to stimuli, even during sleep.