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Oblique Arytenoid Muscle
The oblique arytenoid, the more superficial arytenoid muscle, forms two fasciculi, which pass from the base of one cartilage to the apex of the opposite one, and therefore cross each other like the limbs of the letter X; a few fibers are continued around the lateral margin of the cartilage, and are prolonged into the aryepiglottic fold; they are sometimes described as a separate muscle, the ''Aryepiglotticus''. The aryepiglottic muscle together with the transverse arytenoid and the thyroarytenoid work as a sphincter and close the larynx 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 ... as we swallow or cough. Its innervation is by the recurrent laryngeal nerve (from vagus) just like all the intrinsic muscles of the larynx except the cricothyroid muscle. References External links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larynx
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 ʻlarynxʼ (plural ʻlaryngesʼ) comes from the Ancient Greek word ''lárunx'' ʻlarynx, gullet, throat.ʼ Structure The triangle-shaped larynx consists largely of cartilages that are attached to one another, and to surrounding structures, by muscles or by fibrous and elastic tissue components. The larynx is lined by a ciliated columnar epithelium except for the vocal folds. The cavity of the larynx extends from its triangle-shaped inlet, to the epiglottis, and to the circular outlet at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate Trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by overlying ligaments, and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing. The trachea begins to form in the second month of embryo development, becoming longer and more fixed in its position over time. It is epithelium lined with column-shaped cells that have hair-like extensions called cilia, with scattered goblet cells that produce protective mucins. The trachea can be affected by inflammation or infection, usually as a result of a viral illness affecting other parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recurrent Laryngeal Nerve
The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve (cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and left. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right subclavian artery then traveling upwards. They both travel alongside the trachea. Additionally, the nerves are among the few nerves that follow a ''recurrent'' course, moving in the opposite direction to the nerve they branch from, a fact from which they gain their name. The recurrent laryngeal nerves supply sensation to the larynx below the vocal cords, give cardiac branches to the deep cardiac plexus, and branch to the trachea, esophagus and the inferior constrictor muscles. The posterior cricoarytenoid muscles, the only muscles that can open the vocal folds, are innervated by this nerve. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arytenoid Muscle
The arytenoid muscle is a single muscle of the larynx. It passes from one arytenoid cartilage to the opposite arytenoid cartilage. It has oblique and transverse fibres. It is supplied by the recurrent laryngeal nerve. It approximates the arytenoid cartilages. Continuous electromyography may be used during neck surgeries such as thyroidectomy. Structure The arytenoid muscle fills the posterior concave surface of the arytenoid cartilage. It arises from the posterior surface and lateral border of one arytenoid cartilage. It is inserted into the corresponding parts of the opposite arytenoid cartilage. It consists of oblique and transverse fibres. Nerve supply The arytenoid muscle is supplied by the recurrent laryngeal nerve, a branch of the vagus nerve (CN X). This is a bilateral supply. Function The arytenoid muscle approximates the arytenoid cartilages. This closes the aperture of the glottis, especially at its back part to eliminate the posterior commissure of the vocal c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Fascicle
A muscle fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue. Structure Muscle cells are grouped into muscle fascicles by enveloping perimysium connective tissue. Fascicles are bundled together by epimysium connective tissue. Muscle fascicles typically only contain one type of muscle cell (either type I fibres or type II fibres), but can contain a mixture of both types. Function In the heart specialized cardiac muscle cells transmit electrical impulses from the atrioventricular node (AV node) to the Purkinje fibers – fascicles, also referred to as bundle branches. These start as a single fascicle of fibers at the AV node called the bundle of His that then splits into three bundle branches: the right fascicular branch, left anterior fascicular branch, and left posterior fascicular branch. Clinical significance Myositis may cause thickening of the muscle fascicles. This may be detected with ultrasound scans. Muscle fasci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphincter
A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the human body, some microscopically small, in particular the millions of precapillary sphincters. Sphincters relax at death, often releasing fluids and faeces. Functioning Each sphincter is associated with the lumen (opening) it surrounds. As long as the sphincter muscle is contracted, its length is shortened and the lumen is constricted (closed). Relaxation of the muscle causes it to lengthen, opening the lumen and allowing the passage of liquids, solids, or gases. This is evident, for example, in the blowholes of numerous marine mammals. Many sphincters are used every day in the normal course of digestion. For example, the lower oesophageal sphincter (or cardiac sphincter), which resides at the top of the stomach, is closed most of the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
