Phonology Anatomy

Abduction (vocal folds)

Movement in which the vocal folds separate/open to allow airflow for breathing.

Adam’s Apple (Thyroid Notch)

Prominent anterior point of the thyroid cartilage, especially visible in males.

Adduction (vocal folds)

Movement in which the vocal folds come together/close to trap air or produce voice.

Anterior Commissure

Anterior two-thirds of glottis between vocal fold membranes; vibratory portion; common site of pathology.

Aryepiglottic Muscle

Auxiliary muscle that constricts laryngeal opening by pulling arytenoid apices toward epiglottis; RLN innervated.

Aryepiglottic Folds

Mucosal folds from epiglottis to arytenoids; form lateral walls of laryngeal inlet.

Arytenoid Cartilages

Paired, pyramid-shaped cartilages atop the posterior cricoid; posterior attachment for vocal folds.

Aspiration

Entry of foreign material into the airway or lungs, often prevented by vocal-fold closure.

Cartilaginous Glottis

Posterior one-third of glottis between arytenoid cartilages; does not vibrate.

Cough Reflex

Forceful expulsion triggered to clear substances threatening the airway.

Cricoarytenoid Joint

Synovial joint between cricoid and arytenoid cartilages that rocks, glides, and slightly rotates to abduct or adduct the vocal folds.

Cricoid Cartilage

Ring-shaped, most inferior laryngeal cartilage; articulates with thyroid and arytenoids.

Cricothyroid Muscle

Primary tensor consisting of pars recta and pars oblique; rocks thyroid forward to stretch the folds, raising pitch; SLN (external) innervation.

Cricothyroid Joint

Articulation between cricoid and thyroid cartilages, allowing pitch-changing movements.

Cricotracheal Ligament

Binds cricoid cartilage to first tracheal ring.

Cuneiform Cartilages

Tiny paired cartilages embedded in aryepiglottic folds; add rigidity to supraglottic tissues.

Deep Lamina Propria

Layer of collagen fibers adding strength; together with intermediate forms vocal ligament.

Digastric Muscle (Anterior Belly)

Suprahyoid muscle that draws hyoid up and forward; innervated by trigeminal nerve (CN V).

Digastric Muscle (Posterior Belly)

Suprahyoid muscle that draws hyoid up and back; innervated by facial nerve (CN VII).

Dysphonia

Any disorder of voice quality, pitch, or loudness caused by impaired vocal fold function.

Epiglottis

Leaf-like unpaired cartilage that folds backward to seal the laryngeal inlet during swallowing.

Extrinsic Laryngeal Membranes

Connect larynx to external structures (e.g., thyrohyoid membrane, hyoepiglottic ligament).

Extrinsic Laryngeal Muscles

Muscles with one attachment outside the larynx; elevate or depress the larynx and hyoid for larger positioning movements.

Geniohyoid Muscle

Slender suprahyoid muscle that elevates hyoid and impresses mandible; innervated by C1 via hypoglossal nerve (CN XII).

Genioglossus Muscle

Large tongue muscle that can elevate hyoid when tongue is fixed; CN XII innervated.

Glottis

The space between the vocal folds.

Hyoepiglottic Ligament

Connects hyoid bone to anterior epiglottis, helping epiglottic movement.

Hyoid Depressors

Muscles that lower the hyoid bone, aiding laryngeal depression (infrahyoid group).

Hyoid Elevators

Muscles that raise the hyoid bone, assisting laryngeal elevation (suprahyoid group).

Hyoid Bone

Free-floating bone in the neck; suspends the larynx and serves as muscle attachment site.

Hyoglossus Muscle

Tongue-and-hyoid connector that elevates hyoid and depresses tongue; CN XII innervated.

Infrahyoid Muscles

Group of extrinsic muscles that attach below the hyoid and depress the hyoid/larynx (e.g., sternohyoid, omohyoid, sternothyroid).

Intermediate Lamina Propria

Layer of elastic fibers arranged cross-wise; part of vocal ligament.

Intrinsic Laryngeal Membranes

Connect and support cartilages within the larynx itself (e.g., quadrangular membrane, conus elasticus).

Intrinsic Laryngeal Muscles

Muscles with both origin and insertion on laryngeal cartilages; control fine adjustments for phonation (adduct, abduct, tense, relax).

Laryngeal Inlet (Aditus Laryngis)

Opening connecting pharynx and laryngeal cavity, bounded by epiglottis and aryepiglottic folds.

Laryngeal Pitch Adjustment

Change in vocal pitch achieved mainly by stretching (tensing) or shortening (relaxing) the vocal folds.

Laryngeal Elevators

Muscles that raise the entire laryngeal framework, important in swallowing and pitch increase.

Laryngeal Depressors

Muscles that lower the larynx within the neck, aiding in pitch lowering and post-swallow reset.

Larynx

Musculo-cartilaginous structure at the top of the trachea (C4–C6); houses the vocal folds.

Lateral Cricoarytenoid Muscle

Intrinsic adductor that rocks arytenoids inward/downward to adduct and lengthen the vocal folds; RLN innervated.

Medial Compression

Degree of force with which vocal folds are pressed together; increased by adductor muscles for louder phonation.

Median Thyrohyoid Ligament

Midline thickening of the thyrohyoid membrane between thyroid and hyoid corpus.

Membranous Glottis

Anterior two-thirds of glottis between vocal fold membranes; vibratory portion; common site of pathology.

Minimal Pair

Two words or sounds differing only in voicing (same place and manner), e.g., /b/ vs. /p/.

Musculo-cartilaginous

Composed of both muscle and cartilage tissues (as in the larynx).

Mylohyoid Muscle

Fan-shaped floor-of-mouth muscle elevating hyoid or depressing mandible; mandibular branch of CN V innervated.

Oblique Arytenoid Muscle

Paired intrinsic adductor running in an “X” pattern; pulls arytenoid apices medially and up; RLN innervated.

Omohyoid Muscle (Inferior Belly)

Lower section of omohyoid originating on scapula; joins intermediate tendon to assist hyoid depression.

Omohyoid Muscle (Superior Belly)

Upper section of infrahyoid muscle that depresses hyoid; cervical ansa innervated.

Pars Recta

Vertical part of the cricothyroid that lengthens the vocal folds by rocking the thyroid cartilage downward in front.

Pars Oblique

Oblique part of the cricothyroid that slides the thyroid forward, tensing the vocal folds.

Phonation

The process of producing voiced sound by vibration of the vocal folds within the larynx.

Phoneme

A distinct speech sound; can be voiced (with vocal-fold vibration) or unvoiced (without vibration).

Piriform Sinus

Recess lateral to laryngeal inlet between aryepiglottic fold and thyroid cartilage.

Posterior Cricoarytenoid Muscle

Sole intrinsic abductor that opens the vocal folds by rocking arytenoids laterally; RLN innervated.

Quadrangular Membrane

Upper part of fibroelastic membrane forming false-fold (ventricular) ligaments.

Recurrent Laryngeal Nerve (RLN)

Branch of the vagus that loops under the aorta/subclavian and innervates all intrinsic laryngeal muscles except cricothyroid; vulnerable in heart/thoracic surgery.

Rima Vestibuli

Space between the false vocal folds.

Squamous Epithelium (Vocal Fold)

Thin outer protective layer giving vocal folds their white appearance.

Sternohyoid Muscle

Infrahyoid strap muscle from sternum to hyoid that depresses the hyoid; cervical ansa innervation.

Sternothyroid Muscle

Infrahyoid muscle that depresses thyroid cartilage and, by extension, the larynx; innervated by CN XII & C1–C2.

Stylohyoid Muscle

Suprahyoid muscle from styloid process to hyoid; retracts hyoid posteriorly; CN VII innervated.

Subglottal Pressure

Air pressure below the closed vocal folds, essential for phonation and airway protection.

Subglottal Space

Region below the vocal folds down to the first tracheal ring.

Superior Laryngeal Nerve (SLN)

Vagus branch whose external division innervates the cricothyroid muscle and internal division provides laryngeal sensation above the folds.

Superficial Lamina Propria

Gelatinous layer of elastin fibers under epithelium; allows vocal-fold stretch (Reinke’s space).

Supraglottal Space

Region above the glottis, including vestibule and ventricular folds.

Suprahyoid Muscles

Group of extrinsic muscles that attach above the hyoid and elevate the hyoid/larynx (e.g., digastric, stylohyoid, mylohyoid, geniohyoid).

Synovial Joint

Freely movable joint lined with fluid that allows rocking, gliding, and rotation (e.g., cricoarytenoid, cricothyroid).

Thyroid Cartilage

Largest laryngeal cartilage; forms the Adam’s apple and affects vocal-fold tension and pitch.

Thyroepiglottic Muscle

Auxiliary muscle that dilates the airway by pulling epiglottis back/up; RLN innervated.

Thyrohyoid Membrane

Broad sheet linking thyroid cartilage to hyoid bone.

Thyropharyngeus Muscle

Inferior constrictor component that elevates larynx and constricts pharynx during swallow; innervated by RLN and SLN.

Thyrovocalis (Medial Thyroarytenoid)

Intrinsic tensor forming the medial portion of the vocal fold; tenses vocal folds via RLN.

Thyromuscularis (Lateral Thyroarytenoid)

Intrinsic relaxer lateral to thyrovocalis; relaxes vocal folds when it contracts; RLN innervated.

Transverse Arytenoid Muscle

Unpaired intrinsic adductor that draws arytenoids together for tight vocal fold closure; RLN innervated.

Unvoiced Phoneme

A distinct speech sound; can be voiced (with vocal-fold vibration) or unvoiced (without vibration).

Vallecula

Depression between tongue base and epiglottis; common site for bolus residue.

Vagus Nerve (CN X)

Cranial nerve providing motor and sensory supply to larynx; essential for voice, swallowing, and airway protection.

Ventricular (False) Vocal Folds

Mucosal folds above the true vocal folds; do not normally vibrate in phonation.

Ventricular Fold Phonation

A dysphonia in which damaged true folds are bypassed and the false folds vibrate, producing a low-pitched voice.

Vestibule

Upper supraglottic cavity from aditus to false vocal folds.

Vocal Hygiene

Practices (hydration, avoiding irritants, etc.) that maintain healthy vocal-fold tissue.

Vocal Ligament

Elastic band (intermediate + deep lamina propria) forming the core of each true vocal fold.

Vocal Process (of arytenoid)

Posterior movable attachment point for each true vocal fold on the arytenoid cartilage.

Vocal Folds

Paired soft-tissue bands within the larynx that vibrate to create voice and close to protect the airway.

Voiced Phoneme

A speech sound produced with active vibration of the vocal folds (e.g., /b/, sustained “ah”).