The larynx (voice box) consists of four basic anatomic components:
The cartilaginous skeleton of the larynx, which houses the vocal cords, is made up of the thyroid, cricoid, and arytenoid cartilages. These cartilages are connected to other structures of the head and neck through the extrinsic muscles. The intrinsic muscles of the larynx alter the position, shape, and tension of the vocal cords.
The larynx functions in swallowing, breathing, and voice production. The production of voice can be thought of in terms of three components:
The lungs first supply adequate airflow to overcome the resistance of the closed vocal cords. The vocal cords are finely tuned neuromuscular units that adjust pitch, loudness, and tone by altering their position and tension.
The following diagram illustrates the vocal cord vibration cycle that occurs 200 to 400 times a second during sound production (phonation).The rapid opening and closing of the vocal cords occur in a vibratory pattern and are responsible for sound production. Thus, any structural, inflammatory, or neoplastic lesion of the vocal cord affects voice production and quality.
Final modification of the voice occurs in the mouth, nose, and throat, where the tongue, palate, cheek, and lips are involved in articulation (speech production).