[ANATOMY #3] 1 بسم رلاهللا Please refer back to the slides as these are extra notes only. Slide 2 -The Larynx is a Box of cartilage. -The lower border of c6 is the lower border of cricoid cartilage. -The true and false vocal cords are inside the larynx. -The internal mucosa is pseudostratified ciliated non-keratinized except the true vocal cord epithelium which is stratified squamous non-keratinized. There is submucosa in all of the larynx except the true vocal cords because it is more susceptible to trauma and regeneration (mitosis) so if it had submucosa this will cause edema and suffocation. The true vocal cord also has no blood vessels and no lymphatics so it is white in color. The blood reach the true vocal cords by diffusion. The false vocal cords are red in color and have blood vessels and lymphatics. Laryngopharynx has the inlet of larynx and only air enter the inlet. Hyoid bone is above the larynx (out of it ) and has connection to it by thyrohyoid membrane, ligament and thyrohyoid muscle. Slide 3 Epiglottis is always open for respiration except during deglutition of food. Mechanism of closure : the bolus of food push the epiglottis downward and the larynx will move upward and on the sides we have aryepiglttic folds and aryepiglottic muscle which will cause complete closure of the inlet. The production of voice is through vibration of the true vocal cords which are partially closed. The true vocal cord is adducted, abducted, elongated and shortened by the action of the muscles of the larynx. The difference in voice between males and females is due to the length and tension in the vocal cords and it is a hormonal effect. males have longer and less tense vocal cords so they have low pitch of the voice. females ( hormonal effect by estrogen and progesterone ) so the vocal cords are shorter and more tense so they have a high pitch of the voice. when we adduct the true vocal cords we build a column of air below them in expiration ; when they open suddenly we cough and when we open them normally with vibration we will produce sounds.
2 [ANATOMY #3] slide 4 We have 9 cartilages. Ligaments bind cartilages together. We have joints between the cartilage for movement. Muscles are intrinsic (for the true vocal cord ) and extrinsic(elevate or depress the whole larynx ) The true vocal cord has a ligament called vocal ligament that extend form arytenoid cartilage to thyroid cartilage from the inside. False vocal cords have no function, deep to it we have a mucus gland. Slide 5 The free edge of epiglottis is above the edge of hyoid bone. Thyroid cartilage is open posteriorly and form an angle anteriorly. The thyroid anterior angle has a notch and a prominence ( Adam's apple in males) which is not prominent in females the reason for this is that the vocal cords in males are longer for hormonal reasons so the angle will be acute in contrast with females whom have shorter cords and obtuse angle. -At The apex of arytenoid we have the corniculate cartilage The cuneiform is in the aryepiglotticfold, this fold is also important in the closure of the inlet of the larynx and has aryepiglotticus muscle. Slide 6 The Lower border is the end of larynx. )شبه الخاتم الي اله طبعه ) appearance Signet ring The upper border of the lamina has 2 facets for articulation with arytenoid. The lateral facet articulate with the inferior horn of thyroid cartilage. Slide 7 Regarding the posterior crico-arytenoid muscle,the origin is the depression of cricoid cartilage. From the lateral side is the origin of lateral crico-arytenoid muscle the insertion is the arytenoid cartilage. The function of the muscles is adduction (lateral crico-arytenoid ) and abduction(posterior cricoarytenoid )of the truevocal cords.
[ANATOMY #3] 3 Slides 8,9,10 - Anteriorly on the upper part we have laryngeal prominence (Adam sapple ). - between the superior and inferior horn we have an oblique line for the attachment of muscles like sternothyroid and thyrohyoid The Inferior horn is attached to the lateral facet of the cricoid cartilage. The Vocal cords originate fromthe arytenoid cartilage and insert on the thyroid angle. Slide 11 Regarding the epithelium of the epiglottis: the outer surface epithelium is related to the post 1/3 of the tongue which is stratified squamous non-keratinized epithelium. The inner surfaceepithelium Is pseudostratified ciliated columnar. Epiglottic tubercle attach to the angle of the thyroid cartilage. Slides 12,13 The presence of the depression with the joint allow the rotatory movement. the posterior crico-arytenoidmuscle contraction move the muscular process backward and medially which produce abduction, in contrast the lateral crico-arytenoid (which present on the lateral side of the process ) contraction move the process medially and anteriorly which cause adduction. Vestibular ligament is part of vestibular fold and is originated from the depression for attachment of vestibular ligament corniculate cartilage articulate with the apex and the cuneiform is in aryepiglottic fold above the apex. -Part of the true vocal cord is vocalis muscle and it is a striated skeletal muscle. Slide 14 The function of the cuneiforms in the fold is when there is contraction they help in the complete closure of the inlet of the larynx. Slide 17 The thyrohyoid membrane insert to the upper border of the hyoid bone When there is a thickening of the membrane we call it ligament like in the midline or the lateral side
4 [ANATOMY #3] There is an aperture (perforation) in the lateral side. structures that pass throughthe perforation : 1- superior laryngeal artery branch of superior thyroid artery branch of external carotid artery. 2- internal laryngeal nerve to the larynx to the mucosa above the true vocal cord and it is a sensory nerve. -Below the true vocal cord is supplied by the recurrent laryngeal nerve. -The vagus give superior laryngeal which give internal and external laryngeal nerves. -The external laryngeal is a motor nerve to the cricothyroid muscle for the tense of the true vocal cord(high pitch of the voice ) Slide 18 triticeal cartilage is a collection of small bones in the lateral thyrohyoid ligament. slide 20 Intrinsic ligaments are deep to the mucosa. Slide 21 The free` margin attaches Anteriorly to the thyroid angle Cricothyroid membrane has another name conuselasticus The membrane is inside the thyroid Vocal ligament is part of the true vocal cord Slide 22 The Quadrangular membrane extend from above downward. Slide 23 The space between the two vocal ligaments(rimaglottidis) is smaller than the space between the two vestibular ligaments(rimavestibuli ) Slide 26 All the joints are synovial. The moving of the thyroid cartilage upward cause relaxation of the true vocal cord.
[ANATOMY #3] 5 Slide 27 Crico-arytenoid joints movement is Important in adduction and abduction of the true vocal cords. Done By: Mohammad Alkhoujah.