larynx

Question 1

what is the larynx?

Answer 1

organ of voice production and the parts of the respiratory tract between the lower pharynx and trachea

Question 2

what is the function of the larynx?

Answer 2

acts as a compound sphincter to prevent passage of food/drink into airway
forms a framework of cartilage for the attachment of ligaments and muscles

Question 3

what is the larynx comprised of?

Answer 3

3 unpaired cartilages (epiglottis, thyroid, cricoid)
3 paired cartilages (arytenoid, cuneiform, corniculate)
a fibro-elastic membrane
intrinsic muscles

Question 4

location of larynx

Answer 4

anterior to C3-6

Question 5

innervation of larynx

Answer 5

vagus n. CN X

Question 6

describe the epiglottis

Answer 6

flexible due to high elastin content
attached to thyroid cartilage by thyro-epiglottic ligament
attached to hyoid by hypo-epiglottic ligament

Question 7

describe the thyroid cartilage

Answer 7

largest of the cartilages
two plate-likelaminaefuse anteriorly in the median plane forming laryngeal prominence
Superior to laryngeal prominence, the laminae diverge to form a V-shapedsuperior thyroid notch (there is an inferior notch, but it’s less visible)
The posterior border of each lamina projects superiorly as thesuperior hornand inferiorly as theinferior horn

Question 8

superior border of thyroid cartilage lies _____

Answer 8

opposite C4

Question 9

describe cricoid cartilage

Answer 9

articulates with the thyroid cartilage
shaped like a signet ring
posterior= lamina
anterior= arch

Question 10

3 sided pyramidal cartilages that sit atop of the cricoid cartilage

Answer 10

arytenoid cartilage

Question 11

function of vocal processes on arytenoid cartilage

Answer 11

vocal ligaments attach to these cartilages anteriorly

Question 12

function of muscular processes of arytenoid cartilage

Answer 12

projects laterally to serve as a lever for laryngeal muscles

Question 13

action of arytenoid cartilages

Answer 13

slide, tilt and rotate to approximate, tense and relax vocal cords

Question 14

describe cricothyroid membrane

Answer 14

anteriorly attached to thyroid cartilage
posteriorly attached to vocal process of arytenoid cartilages

Question 15

what is the vocal ligament?

Answer 15

upper margin of cricothyroid membrane that is free and thickened
true vocal cords

Question 16

describe quadrangular membrane

Answer 16

runs between epiglottis and arytenoid cartilages
cuneiform cartilages are contained within this membrane

Question 17

what is the vestibular ligament?

Answer 17

free lower margin of quadrangular membrane
false vocal folds

Question 18

what makes up the vocal fold?

Answer 18

vocal ligament + vocalis m.

Question 19

what is the purpose of the vestibular folds?

Answer 19

serve to protect the vocal folds

Question 20

action of cricothyroid muscles

Answer 20

pulls thyroid cartilage anteriorly on the cricoid cartilage
stretches and tenses vocal cords (high pitch)

Question 21

innervation of cricothyroid muscles

Answer 21

external branch of superior laryngeal nerve (CN X)

Question 22

action of posterior cricoarytenoid muscle

Answer 22

externally rotate the vocal process of the arytenoid cartilages
open the rima glottidis
only abductor of the vocal folds

Question 23

innervation of transverse, oblique, posterior and lateral cricoarytenoid muscle, thyroarytenoid and vocalis muscles

Answer 23

recurrent laryngeal nerve

Question 24

action of lateral cricoarytenoid muscle

Answer 24

internally rotate the vocal process of the arytenoid
close the rima glottidis
adduct vocal folds

Question 25

action of transverse and oblique arytenoid muscles

Answer 25

adduct and narrow laryngeal inlet

Question 26

action of thyroarytenoid and vocalis muscles

Answer 26

narrow laryngeal inlet relax vocal folds

Question 27

describe thyrohyoid membrane

Answer 27

between thyroid cartilage and hyoid laterally contains two apertures which allow internal branch of superior laryngeal n. and superior laryngeal a. passage into the internal surface of larynx

Question 28

describe cricotracheal ligament

Answer 28

attaches the cricoid cartilage to the first tracheal ring

Question 29

describe hypo-epiglottic ligament

Answer 29

attaches epiglottic cartilage to hyoid

Question 30

describe the laryngeal vestibule

Answer 30

extends from laryngeal inlet to vestibular fold comprised of laryngeal inlet and quadrangular membrane

Question 31

describe the central (middle) cavity

Answer 31

space between vestibular and vocal folds laryngeal ventricles and saccules = lateral bulge of the mucosa

Question 32

describe the infraglottic cavity

Answer 32

space from vocal folds to inferior border of cricoid cartilage comprised of cricothyroid membrane and cricoid cartilage

Question 33

what is the rima glottidis?

Answer 33

space between vocal folds

Question 34

what is the rima vestibuli?

Answer 34

space between the vestibular folds

Question 35

motor innervation to cricothyroid

Answer 35

external laryngeal nerve

Question 36

sensory and parasympathetic innervation of larynx superior to vocal folds

Answer 36

internal laryngeal nerve

Question 37

sensory innervation of the larynx inferior to the vocal folds and motor innervation of all intrinsic muscles of the larynx except cricothyroid muscle

Answer 37

recurrent laryngeal nerve

Question 38

what is an important relationship between recurrent laryngeal n. and thyroid gland

Answer 38

the recurrent laryngeal n. ascends superiorly to the posteromedial aspect of the thyroid gland

Question 39

what is an important relationship between the piriform recess and internal laryngeal nerve?

Answer 39

the internal laryngeal n. lies deep to the mucosa of the piriform recess making it vulnerable to injury when a foreign body lodges in the fossa

Question 40

describe the superior laryngeal artery

Answer 40

branch of superior thyroid artery off the external carotid artery supplies upper half of larynx accompanies internal branch of superior laryngeal n. through thyrohyoid membrane

Question 41

describe the inferior laryngeal artery

Answer 41

branch of inferior thyroid artery of thyrocervical trunk of the subclavian artery supplies lower half of larynx ascends in tracheo-esophageal groove with recurrent laryngeal nerve

Question 42

describe lymphatic drainage above the vocal folds

Answer 42

follow superior laryngeal vessels through thyrohyoid membrane and drain into superior deep cervical nodes

Question 43

describe lymphatic drainage below the vocal folds

Answer 43

drain into pre-tracheal or para-tracheal nodes which drain into inferior deep cervical nodes

Question 44

important structures at C3/4

Answer 44

superior border of thyroid cartilage common carotid artery bifurcation location of hyoid