click below
click below
Normal Size Small Size show me how
Larynx
anatomy
Question | Answer |
---|---|
Where is the larynx located? | Posterior to sternohyoid. Anterior to laryngopharynx. Medial to carotid sheath & thyroid glands. Extends from C3-C6. |
How many cartilages form the laryngeal skeleton? What type of cartilage make up most of the skeleton? The least? | Nine. 3 single. 3 paired. Most of it is hyaline. The EPIGLOTTIS & other small stuff is elastic. |
What are the cartilages (parts, I suppose) that make the laryngeal skeleton? | Epiglottic cartilage, thyroid cartilage, cuneiform cartilage, corniculate cartilage, areytenoid cartilage & cricoid cartilage |
What things are formed when the 2 laminae come together to form the thyroid cartilage? | Will form laryngeal prominence (adam's apple), superior thyroid notch, inferior thyroid notch (less distinct). |
What comes off the posterior limits of the thyroid cartilage? Posterolaterlally? | Posteriorly, are the superior and inferior horns. Posterolaterally is the oblique line and the superior and inferior thyroid *tubercles* that are expansions of the line. |
Which cartilage is the only one that completely encircles the airway? What is its function? Is it larger anteriorly or posteriorly | The cricoid cartilage. Provides support to inferior part of larynx. Enlarged lamina in the back, thin arch in the front, so larger posteriorly. |
Where do the arytenoid cartilage lie? What do they articulate with? | In posterior aspect of larynx, in btwn the thyroid cartilage laminae. Base articulates with cricoid below. Apex articulates with corniculate cartilage. |
What attaches to the vocal process of the arytenoid cartilage? What about the muscular processes? | The vocal ligaments to vocal processes. Intrinsic laryngeal muscles ( posterior cricoarytenoids, lateral cricoarytenoids, transverse arytenoids & oblique arytenoids) to the muscular processes. |
Where is the epiglottic cartilage located? Where does it attach? | Posterior to root of tongue & hyoid. Is unattached superiorly. But will attach to thyroid cartilage (anteriorly internal surface) via thin cartilage stalk. |
What do the corniculate cartilages articulate with? | Their bases will articulate with the apices of the arytenoid cartilages |
Where are the cuneiform cartilages located? | Anterior to the corniculate cartilages. W/in aryepiglottic folds. |
What are the changes you'll see in laryngeal cartilage as you age? | More superior in babies and children. In puberty, laryngeal prominence more obvious in males b/c testosterone. These will start to ossify as you get old. |
What are the extrinsic ligaments of the larynx? | Thyrohyoid membrane. Hyoepiglottic ligament. Cricothyroid ligament. |
Where is the thyrohyoid membrane thickened? What can you find in it? | In the middle/midline, forming median thryohyoid ligament. In the posterior edges, making the lateral thyrohyoid ligament, which may contain triticeal cartilage. There will also be opening for superior laryngeal VESSELS & internal laryngeal NERVE |
What are the intrinsic ligaments of the larynx? | Conus elasticus/cricothyroid ligament. Quadrangular ligament. Thryoepiglottic ligament. |
Where does the cricothyroid ligament attach? | From superior surface of cricoid cartilage to vocal processes of the aryetenoid cartilages and the inner surface of angle btwn thyroid laminae. |
Where is the cricothyroid ligament thick? What do we call the rest of the ligament that isn't thick? | Anteriorly, where it forms the median cricothyroid ligament. The lateral cricothyroid ligament. |
What is the vocal ligament? | The upper edge of the cricothryoid ligament, formed by the attaching of it to the arytenoid cartilages & inner surface of angle btwn thyroid laminae. |
Where is the quadrangular ligament located? | Running in btwn lateral parts of epiglottic and arytenoid cartilages. Under the mucosa (b/c it's submucosal). |
Where does the quadrangular ligament attach? | To arytenoid cartilage posteriorly just inferior to apex. And then to thyroid cartilage just superior to where vocal ligaments attach along the inner surface of the angle btwn thyroid laminae. |
What forms the vestibular ligament? | The free inferior margins of the quadrangular ligament w/in the vestibular fold. |
What forms the aryepiglottic ligament? | The free superior margin of the quadrangular ligament w/in the aryepiglottic fold. |
What does the aryepiglottic fold contain? | Corniculate & cuneiform cartilages. |
What does the thyroepiglottic ligament do? | Attaches the tapered part of epiglottic cartilage to internal middle part of thyroid midline. |
What are the joints found in the larynx? What kind of joints are they? | Cricothyroid joints & cricoarytenoid joint. They're both synovial. |
Where is the cricothyroid joint? | Formed btwn medial side of inferior horns of THYROID cartilage & lateral surfaces of cricoid cartilage. |
What happens to the vocal folds when thyroid cartilage tilts anteriorly? | Vocal folds are tensed when thyroid cartilage tilts anterior AT cricothyroid joint. |
Where is the cricoarytenoid joint? | Btwn base of arytenoid cartilages and posterosuperior aspect of cricoid cartilage. |
Why is it important that the cricoarytenoid joint is synovial? | Allows arytenoids to slide & pivot on cricoid, which allows abduction/adduction of the vocal ligaments. |
What is the larynx continuous with? | Pharynx superiorly. Trachea inferiorly. |
Where does larynx open superiorly? What is the opening bound by? | At laryngeal inlet/aditus, where it opens into ANTERIOR part of pharynx (just behind tongue). Bounded anteriorly by epiglottis, posteriorly by artyenoids and the aryepiglottic folds. |
Where does larynx open inferiorly? | Well...it's continuous with trachea...And always open. Is completely encircled by cricoid. |
What are the divisions of the larynx? | Vestibule. Middle pt of laryngeal cavity (laryngeal ventricle). Infraglottic space. |
Where does the vestibule start and end? | Superior boundary is laryngeal inlet. Inferior boundary are the vestibular folds. Can also say that the inferior boundary is the rima vestibuli. |
What is the rima vestibuli? | The space formed btwn the 2 vestibular ligaments enclosed in the vestibular folds. |
Where is the middle part of laryngeal cavity? What does it contain? | Narrow space btwn vestibular and vocal folds. The laryngeal ventricle, laryngeal saccule, and the glottis. |
What is the laryngeal ventricle? What does it form? | A gap btwn the vocal folds and vestibular folds. It forms an extension anterosuperiorly just behind the thyroid cartilage, into a kind of pouch. The saccule holds many mucous glands. |
What do the vocal folds consist of? What is the space btwn the two folds called? | The vocal ligament, vocalis muscle & mucosal covering. The space in btwn is called rima glottidis. |
Are vocal folds true vocal cords? | YES |
What is the vocal apparatus? | The vocal folds AND rima glottidis together. Apparatus is also called GLOTTIS. |
What does the rima glottidis looks like when breathing normally? During forced breathing? When talking/making sounds? | Narrow w/nl breathing. Wide when forcing breaths. Slit like during phonation. |
Where does the infraglottic space extend to and from? | Goes from vocal folds down to inferior opening of larynx, when we reach trachea. |
What is the general function of the extrinsic muscles of the larynx? What were those muscles again? | Muscles include suprahyoid & infrahyoid muscles. Gen function is to move ENTIRE LARYNX, esp raising/lowering it b/c swallowing or talking, b/c of attachment to hyoid. |
What are the gen functions of intrinsic muscles of larynx? | Gen function is to move PARTS of larynx *with respect to each other* so larynx can do what it is supposed to do. Like the actual talking and being a sphincter for lower resp tract. |
What are the intrinsic muscles of the larynx? | cricothyroid, thyroarytenoid, vocalis, thyroepiglottic, lateral cricoarytenoid, transverse arytenoid, and oblique arytenoid. |
Where does the cricothyroid muscle attach? Where can you find it on the body? | From arch of cricoid cartilage up to the inferior edge & inferior horn of thyroid cartilage. Is on external & lateral aspect of larynx. |
What happens when the cricothyroid contracts? | Contraction will cause thyroid cartilage to rotate anteriorly and inferiorly toward cricoid. That will tense the vocal folds and raise the pitch of your voice. |
Where is the thyroarytenoid muscle? Where does it attach? | Deep to thyroid laminae. Attaches from inferior pt of thyroid angle and adj cricothyroid ligament into anterolateral surface of arytenoid cartilage & lateral to quadrangular ligament. |
What happens when the thryoarytenoid muscle contracts? | Pulls arytenoid cartilages anteriorly toward thyroid cartilage via cricoarytenoid joint. This relaxes vocal ligament/fold, lowering the pitch of the voice. |
Where is the vocalis muscle? Where does it attach? | It runs parallel with vocal ligament towards thyroid cartilage. It attaches to anterolateral side of arytenoid cartilage & its vocal process to thyroid cartilage. |
What is the vocalis muscle a part of? And what does the vocalis muscle do? | Is part of thryoarytenoid muscle. It fine tunes tension on vocal folds & changes mass of the cords to change timbre of voice. |
What is the thyroepiglottic muscle a part of? Where does it extend into? | Part of thyroarytenoid muscle that extends into aryepiglottic fold. |
What does the thyroepiglottic muscle do? | Acts as sphincter for laryngeal vestibule. |
Where does the lateral cricoarytenoid muscle attach? | Superior aspect of arch of cricoid (above where cricothyroid muscle attached). Then goes back and up to the muscular processes of the arytenoids. |
What does the cricoarytenoid muscle do when it contracts? | Will bring vocal processes medial, causing vocal folds to adduct and close the rima glottis. |
Where does the transverse arytenoid muscle attach? What does it do? | To the lateral aspect of ea arytenoid cartilage, spanning btwn the two posteriorly as it joins them together. Will help adduct the vocal folds. |
Where are the oblique arytenoid muscles? Where do they attach? | They cross each other just posterior to the transverse arytenoids. Running from posterior surface of muscular process of one arytenoid to the apex of the other (contralaterally). |
What do the oblique arytenoid muscles do? | They also help adduct the vocal folds. |
What is the blood supply to the larynx? | Superior laryngeal artery (thru the thyrohyoid membrane, off superior thyroid artery) & inferior laryngeal artery (off inferior thyroid artery). |
What is the path of the inferior laryngeal artery? | Comes up deep to inferior border of inferior constrictor. Enters larynx by passing deep near cricothyroid joint. |
Where does blood from larynx drain into? | Superior laryngeal vein and inferior laryngeal vein. |
What does superior laryngeal vein accompany? And what does it drain thru? | Accompanies superior laryngeal artery. Will usually drain thru superior thyroid vein into IJV. |
What does the inferior laryngeal vein drain into? | Drains into inferior thyroid vein and will then usually empty into L brachiocephalic. |
Where does lymph drain from areas above the vocal cord? | They'll follow the superior laryngeal vessels to the SUPERIOR DEEP cervical lymph nodes. |
Where does lymph from below the vocal cords (infraglottic region) drain? | Will drain to PREtracheal or PARAtracheal nodes *then* to INFERIOR DEEP cervical lymph nodes. |
What provides sensory and motor to the entire larynx? | VAGUS. |
Where are sensory neuron cell bodies for vagus? | The inferior ganglion of vagus |
Where are motor neurons and pregang parasympathetic neuron cell bodies for the laryngeal muscles? | brainstem |
What branches of vagus supply sensation and parasympathetic input to larynx at vocal folds and ABOVE. | internal laryngeal off superior laryngeal |
What innervates the cricothyroid muscle? | external laryngeal off superior laryngeal. descends right on top of inferior constrictor. |
What innervates all instrinsic muscles of larynx (except cricothyroid), as well as transmit sensory and parasympathetic fibers for inferior part of larynx? | Inferior laryngeal nerve that continues off recurrent laryngeal. |
Where is the inferior laryngeal nerve? | Passes deep to inferior border of inferior constrictor into larynx. Will split into several branches to innervate the intrinsic muscles of the larynx. |
Where are the sympathetic postgang cell bodies for the larynx at? | In the superior or middle cervical sympathetic ganglia. |
What will happen to the larynx if the internal laryngeal nerve gets damaged? | Desensitization of superior larynx. Higher probability of laryngeal foreign bodies and choking. |
What will happen to the larynx if the external laryngeal nerve gets damaged? | Paralysis of cricothyroid muscle that causes lowered pitch and monotonous tone. |
What will happen to the larynx if the inferior laryngeal nerve gets damaged? | The vocal folds get paralyzed, so you can't control their tone.... |