Term
| understand where the valleculae, vestibule, and piriform recesses are located. |
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Definition
| The valleculae are spaces located on either side of the midline posterior to the tongue and anterior to the epiglottis. The piriform recess is the space in the laryngopharynx just posterior to the larynx between the thyroid cartilage and the aryepiglottic fold. The vestibule is the space posterior to the epiglottis between the aryepiglottic folds and above the false vocal folds. It is the entryway to the respiratory tract. |
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Term
| know the pathway for food material as it passes to the esophagus without passing into the airway. |
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Definition
| Food passes over the posterior surface of the tongue as it is swallowed and into the valleculae. It then passes to either side of the epiglottis and around it into the piriform recesses and then enters the upper portion of the esophagus. |
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Term
| know what is the narrowest part of the airway and where is it located. |
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Definition
| The narrowest part of the airway is the rima glottidis, which is the space found between the true vocal cords (vocal ligaments). This space changes shape when speaking, coughing, or breathing heavily. |
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Term
| understand what nerves innervate the mucosal surface of the larynx and where they originate. |
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Definition
| The mucosal surface down to the level of the vocal cords is innervated by the internal laryngeal branch of the superior laryngeal nerve. The mucosa up to the level of the vocal cords is innervated by branches of the inferior (recurrent) laryngeal nerve. Both laryngeal nerves are derived from the vagus nerve. |
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Term
| know what composes the laryngeal skeleton (cartilages). How do these cartilages articulate with one another? |
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Definition
| The major cartilage components of the larynx are the thyroid cartilage, cricoid cartilage, the epiglottis, and the arytenoid cartilages. The thyroid cartilage and cricoid cartilage articulate with one another laterally while the arytenoid cartilages articulate with the upper posterior surface of the cricoid. |
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Term
| where the thyrohyoid, cricothyroid, and quadrangular membranes are located and how they shape the laryngeal complex. |
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Definition
| The thyrohyoid membrane is a connective tissue membrane stretching between the thyroid cartilage and the hyoid bone and is perforated by the internal laryngeal nerve and superior laryngeal artery. The cricothyroid membrane connects the thyroid and cricoid cartilages and helps form the anterior aspect of the complex. The quadrangular membrane stretches from the epiglottis to the aryteoid cartilages. It free inferior margin helps form the false vocal fold and this connective tissue membrane helps form the backing for the wall of the vestibule. |
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Term
| the muscles that change the position and tension of the vocal cords, how this is accomplished, and what nerve innervates them. |
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Definition
| The muscles are innervated by the inferior (recurrent) nerve that is a branch of the vagus. The vocal cord or ligament is attached to the thyroid cartilage anteriorly and to the vocal process of the arytenoid posteriorly. The vocal cords are approximated (adduct) or separated (abduct) by the movement of the vocal process or stretched (tensed) by the movement of the cricoid and thyroid cartilages. Abduction of cords – posterior cricoarytenoid muscle. Adduction of cords – lateral cricoarytenoid, arytenoids. Stretch vocal cords – cricothyroid muscle. The vocalis portion of thyroarytenoid muscle alters tension of vocal fold, relaxes it, and changes pitch. |
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Term
| understand when the vocal cords are opened and closed. Why are they closed to cough. |
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Definition
| The vocal cords are closed when attempting to increase intra-thoracic and/or intra-abdominal pressure or just prior to coughing. They are opened slightly when producing sound for speaking, opened slightly wider for normal breathing, and opened very wide during forced respiration. |
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Term
| know how sound is produced. |
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Definition
| Sound is produced when the vocal cords (or ligaments) are approximated, and air is moved from the thoracic cavity through the narrow gap between them, the rima glottides. Movement of air causes the cord to vibrate which produces sounds. The pitch is changed as a result of contraction of the vocalis muscle that changes the tension along the cords. The sound produced is then modified by the mouth, tongue, lips, etc. |
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Term
| know the difference between true and false vocal folds. What is found between them? |
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Definition
| The true vocal folds are the more inferior and are where sound is actually produced. The space or gap between the two vocal cords is known as the rima glottidis. The false vocal folds are located at the inferior edge of the vestibule just above the true vocal folds. The space between the true and false vocal folds is known as the ventricle. |
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Term
| where is the vocal ligament or cord is located. |
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Definition
| The actual vocal cord or ligament is located at the free medial edge of the fold so that it is exposed to the air rushing by and can therefore vibrate. |
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Term
| what is the function of the vocalis muscle. |
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Definition
| The vocalis muscle is the midline fibers or portion of the larger thyroarytenoid muscle. It is responsible for altering the tension of the vocal ligament and thus changing the pitch of the voice. |
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Term
| why damage to the inferior laryngeal nerves is important. |
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Definition
| The inferior laryngeal nerves control movement of the intrinsic muscles of the larynx. Therefore damage to the nerve results in muscle malfunction and loss of control of air movement and, of course, voice. |
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Term
| what happens if only one nerve is damaged. |
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Definition
| Damage to only one nerve results in impaired movement of cords on one side resulting in hoarseness. |
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Term
| how the Heimlich maneuver works and review what is done during a cricothyrotomy. |
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Definition
| Foreign objects often lodge in the vestibule just above the vocal folds. During the Heimlich maneuver the thoracic cavity is squeezed quickly, increasing thoracic pressure and forcing air up against the lodged object. Hopefully enough pressure is exerted that the object is moved out of the airway and the air can begin moving back and forth in normal respiration. Remember a cricothyrotomy is done to open an airway in an emergency. The airway is very close to the surface at the level of the vocal cords. It is separated from the outside only by the thickness of the skin and the cricothyroid membrane. These are incised and a hollow object is placed in the opening to maintain patency and allow air to move in and out. This position is usually below the level of the blockage so air movement can take place. |
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