| Rima glottidis | |
|---|---|
 Muscles of the larynx, seen from above | |
 The entrance to the larynx. | |
| Details | |
| Identifiers | |
| Latin | rima glottidis |
| TA98 | A06.2.09.014 |
| TA2 | 3208 |
| FMA | 55472 |
| Anatomical terminology | |
The rima glottidis is the opening between the two true vocal cords anteriorly, and the two arytenoid cartilages posteriorly. It is part of the larynx. [1]
The rima glottidis is the narrowest part of larynx. It is longer (~23 mm) in males than in females (17–18 mm). [1]
The rima glottidis is an aperture between the two true vocal cords anteriorly, and the bases and vocal process of the two arytenoid cartilages posteriorly. It is therefore described as subdivided into two parts: the larger anterior part between the vocal folds (intermembranous part, or glottis vocalis), and the smaller posterior part between arytenoid cartilages (intercartilaginous part, glottis respiratoria, intercartilaginous glottis, respiratory glottis, or interarytenoid space[ citation needed ]). It is limited posteriorly by an interarytenoid fold of mucous membrane. [1]
The rima glottidis is closed by the lateral cricoarytenoid muscles and the arytenoid muscle, and opened by the posterior cricoarytenoid muscles. All of these muscles receive innervation from the recurrent laryngeal nerve which is a branch of the vagus nerve (CN X).[ citation needed ]
The shape of rima glottidis is changed by movements of vocal cords and arytenoid cartilages during respiration and phonation. [1]
Any damage to the rima glottidis may result in a hoarse voice, aphonia or difficulty breathing.[ citation needed ]
The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology and speech production in general. Phoneticians in other subfields, such as linguistic phonetics, call this process voicing, and use the term phonation to refer to any oscillatory state of any part of the larynx that modifies the airstream, of which voicing is just one example. Voiceless and supra-glottal phonations are included under this definition.
The larynx, commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch and volume, which is essential for phonation. It is situated just below where the tract of the pharynx splits into the trachea and the esophagus. The word 'larynx' comes from the Ancient Greek word lárunx ʻlarynx, gullet, throat.ʼ
The lateral cricoarytenoid is an intrinsic muscle of the larynx. It attaches at the cricoid cartilage anteriorly, and at the arytenoid cartilage of the same side posteriorly. It is innervated by the recurrent laryngeal nerve. It acts to close the rima glottidis, thus closing the airway.
The posterior cricoarytenoid muscle is a intrinsic muscle of the larynx. It arises from the cricoid cartilage; it inserts onto the arytenoid cartilage of the same side. It is innervated by the recurrent laryngeal nerve. Each acts to open the vocal folds by pulling the vocal fold of the same side laterally. It participates in the production of sounds.
The cricoid cartilage, or simply cricoid or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment site for muscles, cartilages, and ligaments involved in opening and closing the airway and in producing speech.
The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It is innervated by the superior laryngeal nerve. Its action tilts the thyroid forward to help tense the vocal cords, thus increasing the pitch of the voice.
The arytenoid cartilages are a pair of small three-sided pyramids which form part of the larynx. They are the site of attachment of the vocal cords. Each is pyramidal or ladle-shaped and has three surfaces, a base, and an apex. The arytenoid cartilages allow for movement of the vocal cords by articulating with the cricoid cartilage. They may be affected by arthritis, dislocations, or sclerosis.
The stylopharyngeus muscle is a muscle in the head. It originates from the temporal styloid process. Some of its fibres insert onto the thyroid cartilage, while others end by intermingling with proximal structures. It is innervated by the glossopharyngeal nerve. It acts to elevate the larynx and pharynx, and dilate the pharynx, thus facilitating swallowing.
The arytenoid muscle or interarytenoid muscle is a composite intrinsic muscle of the larynx, consisting of a transverse part and an oblique part - the two parts may be considered as separate muscles: an unpaired transverse arytenoid muscle, and a bilaterally paired oblique arytenoid muscle.
The thyroarytenoid muscle is a broad, thin muscle that forms the body of the vocal fold and that supports the wall of the ventricle and its appendix. It functions to shorten the vocal folds.
In the human larynx, the cuneiform cartilages are two small, elongated pieces of yellow elastic cartilage, placed one on either side, in the aryepiglottic fold.
The oblique arytenoid is bilaterally paired intrinsic muscle of the larynx. It is superficial to the transverse arytenoid; the oblique and transverse arytenoids are often considered two parts of a single muscle - the interarytenoid muscle.
The aryepiglottic folds are triangular folds of mucous membrane of the larynx. They enclose ligamentous and muscular fibres. They extend from the lateral borders of the epiglottis to the arytenoid cartilages, hence the name 'aryepiglottic'. They contain the aryepiglottic muscles and form the upper borders of the quadrangular membrane. They have a role in growling as a form of phonation. They may be narrowed and cause stridor, or be shortened and cause laryngomalacia.
The transverse arytenoid is an unpaired intrinsic muscle of the larynx. It is situated deep to the two oblique arytenoids; the oblique and transverse arytenoids are often considered two parts of a single muscle - the interarytenoid (arytenoid) muscle.
The quadrangular membrane is a layer of submucosa. It extends between the lateral margin of the epiglottis, and the apex and fovea triangularis of the ipsilateral arytenoid cartilage. It has free superior and inferior borders.
In the human larynx, the vocal process is the anterior angle of the base of the arytenoid cartilage, as it projects horizontally forward and gives attachment to the vocal ligament.
Histology is the study of the minute structure, composition, and function of tissues. Mature human vocal cords are composed of layered structures which are quite different at the histological level.
Endoscopic laser cordectomy, also known as Kashima operation, is an endoscopic laser surgical procedure performed for treating the respiratory difficulty caused as a result of bilateral abductor vocal fold paralysis. Bilateral vocal fold paralysis is basically a result of abnormal nerve input to the laryngeal muscles, resulting in weak or total loss of movement of the laryngeal muscles. Most commonly associated nerve is the vagus nerve or in some cases its distal branch, the recurrent laryngeal nerve. Paralysis of the vocal fold may also result from mechanical breakdown of the cricoarytenoid joint. It was first described in by Kashima in 1989.
Thyroplasty is a phonosurgical technique designed to improve the voice by altering the thyroid cartilage of the larynx, which houses the vocal cords in order to change the position or the length of the vocal cords.
Arytenoid adduction is a surgical procedure used to treat vocal cord paralysis. A suture is used to emulate the action of the lateral cricoarytenoid muscle and position the paralyzed vocal cord closer to the midline. This allows the two vocal cords to meet and can improve speaking and swallowing ability for affected patients. Arytenoid adduction is often performed in conjunction with medialization thyroplasty.
 | This anatomy article is a stub. You can help Wikipedia by expanding it. |
