GENERAL INFORMATION
The larynx, or voice box, is an important anatomical structure in the neck, given its size; it highly contributes to respiration, voice-making, and also to the protection of the trachea against aspiration of food. It directly sits above the trachea, contains the vocal cords, and thus plays a role in producing sound. Moreover, the larynx serves as a passage for air to penetrate the lungs.
ORIGIN OF LARYNX
The larynx is primarily made up of cartilage, muscles, and ligaments. The significant parts of the larynx include thyroid cartilage, cricoid cartilage, and epiglottis. The intrinsic muscles of the larynx originate from different points on these cartilaginous structures.
INSERTION POINT
The laryngeal muscles differ in the insertion points, attaching to many places within the arytenoid cartilages and other parts of the laryngeal framework to enable complex control over vocal cord tension and position.
MAJOR ARTERIES OF LARYNX
- Superior laryngeal artery
- Inferior laryngeal artery
These arteries branch from the superior thyroid artery and provide essential blood flow to the larynx.
NEURAL INNERVATION
- Recurrent Laryngeal Nerve: is a branch of the vagus nerve. It innervates most of the intrinsic muscles of the larynx.
- Superior Laryngeal Nerve: It provides innervation to the cricothyroid muscle and sensory input to the mucosa above the vocal cords.
TRIGGER POINT
Tension in the laryngeal muscles will result in discomfort, a hoarse voice, or an inability to articulate. Tension or irritation of the vocal cord and associated muscles will cause pain or strain when speaking or swallowing.
CONCENTRIC FUNCTION
During concentric contraction, laryngeal muscles contract and shorten to produce sound. Vocal cords are adducted- that is, brought closer to each other so that tension, length, and position of the vocal cords render phonic contraction.
ECCENTRIC FUNCTION
In eccentric function, the laryngeal muscles gradually lengthen and release tension, allowing the vocal cords to separate (abduction) for breathing or modulating pitch and sound intensity during speech.
ISOMETRIC FUNCTION
Isometrically, the laryngeal muscles stabilise the position of the vocal cords without changing length. This function is crucial during sustained vocalisation, such as holding a note or during prolonged speech.
RELATED MUSCLES – SCIENTIFIC NAMES
- Cricothyroid Muscle: Adjusts tension in the vocal cords for pitch control.
- Thyroarytenoid Muscle: Helps shorten and relax the vocal cords.
- Lateral Cricoarytenoid Muscle: Adducts the vocal cords.
- Posterior Cricoarytenoid Muscle: Abducts the vocal cords.
- Vocalis Muscle: Fine-tunes tension in the vocal cords for precise sound modulation.
ANTAGONIST
- Posterior Cricoarytenoid Muscle: Works against the lateral cricoarytenoid muscle by abducting the vocal cords.
- Lateral Cricoarytenoid Muscle: Opposes the posterior cricoarytenoid by adducting the vocal cords.
COMMON INJURIES OF FOR LARYNX
- Vocal Cord Nodules: Small, benign growths due to overuse, causing hoarseness and pain.
- Laryngitis: Inflammation of the larynx, often from infection or overuse, leading to temporary voice loss.
- Vocal Cord Paralysis: Weakness or immobility of one or both vocal cords, resulting in a breathy or weak voice.
- Strained Vocal Cords: Often caused by shouting or prolonged talking, causing soreness and also making one unable to produce clear sounds.
- Laryngeal Reflux: Acid reflux that irritates the larynx, causing chronic throat clearing or hoarseness.
EXERCISES FOR LARYNX
- Humming Exercise: This exercise will help the vibration and relaxation of the vocal cords by humming softly at different pitches. It is most suited for voice warm-up without strain.
- Lip Trills: Blow air through your lips while making a “brrr” sound. This exercise helps improve breath control and ease tension in the vocal cords.
- Pitch Glides: Start at a low pitch and glide up to the highest pitch possible, then reverse. This exercise helps stretch the vocal cords and increase flexibility.
- Vowel Practice: Include sustained vowels, like “A” and “E,” at different pitches to build vocal stamina besides vocal cord strengthening.
- Breath Control Drill: Deep inhale; slow exhale and speak steadily with a proper tone to build pulmonary capacity and voice control.
STRETCHES FOR LARYNX
- Neck Tilts: Slowly tilt the head to each side, holding for 20-30 seconds to release tension in the neck muscles, which indirectly supports the larynx.
- Neck Rotation Stretch: Gently rotate the head in circular motions to loosen up the muscles surrounding the larynx and improve flexibility.
- Tongue Stretch: Stick your tongue out as far as possible and keep it extended for 10 seconds. This movement stretches the muscles at the base of the tongue, reducing tension on the vocal cords.
- Jaw Release Stretch: Open and close the jaw gently to reduce tightness in the surrounding muscles and promote relaxation in the laryngeal area.
- Shoulder Shrugs: Up Lift your shoulders towards your ears, hold briefly, and then relax. This stretch helps reduce tension that can affect the laryngeal muscles.