Lecture 55 Larynx & Pharynx

Question 1

Name the pharyngeal muscles.

Answer 1

paired superior, middle, and inferior constrictors

paired longitudinal muscles (salpingopharyngeus, palatopharyngeus, and stylopharyngeus)

Question 2

What are the three divisions of the pharynx?

Answer 2

nasopharynx, oropharynx, laryngopharynx

Question 3

Name the paired and unpaired laryngeal cartilages.

Answer 3

paired: corniculate, cuneiform, and arytenoid
unpaired: epiglottis, thyroid, cricoid

Question 4

The fibroelastic membrane of the larynx compartmentalizes into the ____ and the ____.

Answer 4

upper quadrangular and lower conus elasticus

Question 5

What surgical procedure is associated with the cricothyroid membrane?

Answer 5

cricothyrotomy emergency procedure

Question 6

Innervation of the pharynx is comprised of the ____ plexus, i.e CN ____, CN ____, and cranial root of CN ____ as well as autonomics.

Answer 6

Pharyngeal
IX (Glossopharyngeal)
X (Vagus)
XI (Spinal Accessory)

Question 7

Sensory innervation of the larynx is comprised of the upper surface of the vocal folds and above via the ____ nerve and lower surface of the vocal folds and below via the _____ nerve.

Answer 7

superior laryngeal nerve

recurrent laryngeal nerve

Question 8

Motor innervation of the larynx is comprised of all intrinsic muscles via _____ nerve - except the cricothyroid which is innervated by the _____ nerve.

Answer 8

recurrent laryngeal nerve

superior laryngeal nerve

Question 9

In humans, the pharynx is not a structure as much as it is an ____ with ____ main portals.

Answer 9

open ended tube

3

Question 10

Describe the three main portals of the pharynx.

Answer 10

two open superiorly (one into the back of the nasal cavity (choanae) and one into the back of the oral cavity)
one communicates inferiorly being continuous with the esophagus

Question 11

The pharynx is, in essence, a “space” that is bound by muscles and perforated by openings. It can be divided into what three regions?

Answer 11

nasopharynx
oropharynx
laryngopharynx

Question 12

What structures mark the margins of the nasopharynx?

Answer 12

internal nares superiorly to the inferior margin of the soft palate inferiorly

Question 13

What structures mark the margins of the oropharynx?

Answer 13

the soft palate superiorly to the tip of the epiglottis inferiorly and extending anteriorly to the palatoglossal folds

Question 14

What structures mark the margins of the laryngopharynx?

Answer 14

the tip of the epiglottis superiorly to the inferior margin of the cricoid cartilage of the larynx inferiorly

Question 15

Waldeyer’s Ring, a protective “doughnut” at the back of the throat, is positioned to catch unwanted material. What is it composed of?

Answer 15

superior region, nasopharyngeal tonsils (adenoids)
back of the oral cavity with collections on the tongue (lingual tonsils)
between the palatoglossal and palatopharyngeal folds (palatine and facial tonsils, collectively call :the tonsils”)

Question 16

What is the role of the three paired constrictor muscles of the pharynx?

Answer 16

constrict food and guide it towards the esophagus

Question 17

What is the role of the three pairs of longitudinal muscles of the pharynx?

Answer 17

elevate the constrictors

Question 18

What is the only muscle in humans thought to be derived from the 3rd branchial arch (and thus the ONLY muscle that receives its SVE innervation from CN IX)?

Answer 18

stylopharyngeus

Question 19

What opening (ostium) is located in the lateral wall of the nasopharynx that communicates with the middle ear?

Answer 19

eustachian tube

Question 20

The vocal ligament spans from the ____ cartilage posteriorly to the ____ cartilage anteriorly.

Answer 20

arytenoid

thyroid

Question 21

Which structures comprise the “true vocal cords”?

Answer 21

vocal folds (overlying mucosa + vocal ligaments)

Question 22

Which structures comprise the “false vocal cord”?

Answer 22

Vestibular folds (overlying mucosa + vestibular ligaments)

Question 23

Below the anterior attachment of the vocal ligaments to the thyroid cartilage is a membrane through which an emergency opening into the airway is done outside of an operating room (cricothyrotomy). What is the name of this membrane?

Answer 23

cricothyroid ligament

Question 24

The larynx is derived embryologically from which branchial arches?

Answer 24

4th to 6th

Question 25

What special nerve arises from the Vagus Nerve (CN X), recurring around the ligamentum arteriosum (remnant of the L 6th aortic arch) and goes cranially on the trachea towards the larynx?

Answer 25

L recurrent laryngeal nerve

Question 26

The larynx is innervated by what two major nerves that carry both motor and sensory innervation?

Answer 26

Recurrent laryngeal nerve and superior laryngeal nerve

Question 27

What nerve innervates all of the intrinsic muscles of the larynx EXCEPT the cricothyroid muscle and carries general sensation from the inferior surface of the vocal folds and below?

Answer 27

recurrent laryngeal nerve

Question 28

What nerve innervates ONLY the cricothyroid muscle and carries sensation from the superior surface of the vocal folds and above?

Answer 28

superior laryngeal nerve

Question 29

The superior laryngeal nerve and cricothyroid muscle are thought to be derived directly from which branchial arch and are associated with what cranial nerve?

Answer 29

4th branchial arch
Vagus Nerve (CN X)

Question 30

The recurrent laryngeal nerve and all other intrinsic muscles (minus the cricothyroid muscle) have cell bodies in a distinct group of neurons in the most caudal aspect of the nucleus known as what and are carried in a collection of fibers traditionally known as what?

Answer 30

nucleus ambiguus of the brainstem

“cranial root” of the Spinal Accessory Nerve (CN XI) from the 5th/6th branchial arch

Question 31

What muscle is the only abductor of the larynx?

Answer 31

posterior cricoarytenoid muscle