Larynx

Question 1

Dissection of Larynx: [17-minute video]

Answer 1

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Question 2

The larynx is the upper expanded part of the lower respiratory tract, which is modified for producing voice, hence it is also called voice box/organ of phonation. List the functions of larynx.

Answer 2

1. Phonation. 2. Respiration. 3. Protection. 4. Deglutition.

Note: The primary (most important) function of the larynx is protection of the lower respiratory tract. The phonation has developed later with evolution and is related to the motor speech area of the brain.

Question 3

The larynx is composed of 9 cartilages, of which 3 are unpaired and 3 are paired. Name them.

Answer 3

(1) Unpaired cartilages: The unpaired cartilages are large and comprise:
(a) Thyroid (b) Cricoid (c) Epiglottis
(2) Paired cartilages: The paired cartilages are small and comprise:
(a) Arytenoid (b) Corniculate (c) Cuneiform [5-minute video]

[Diagram 1] [Diagram 2] [Diagram 3]

Note: The principal cartilages of the larynx are, cricoid, thyroid, and two arytenoids
[13-minute video]: skeleton of larynx and intrinsic laryngeal musculature

Question 4

State the extents of the larynx.

Answer 4

It extends from the root of the tongue to the trachea and lies in front of the 3rd, 4th, 5th, and 6th cervical vertebrae. However, in children and females it lies at a little higher level.
Alt: from the laryngeal inlet to the lower border of the cricoid cartilage

Question 5

The epiglottis
The broad upper end of the epiglottis is free and forms the upper boundary of the laryngeal inlet, while the lower end (stalk) is pointed and connected to the posterior surface of the angle of the thyroid by the ____(a)____ ligament. The anterior surface of epiglottis is connected with the base of the tongue by the ____(b)____. The depression on each side of the median fold is called ____(c)____.

Answer 5

(a) thyroepiglottic
(b) median and lateral glossoepiglottic folds
(c) valeculla

[Diagram]

Question 6

(a) Name the two processes of the arytenoid cartilage.
(b) The apex of the artyenoid cartilage articulates with the ____________ cartilage.

Answer 6

(a) muscular process, vocal process
(b) corniculate

Question 7

Name all the extrinsic muscles of the larynx and state their function.

Answer 7

(a) Palatopharyngeus.
(b) Salpingopharyngeus.
(c) Stylopharyngeus.
(d) Thyrohyoid.
(e) Sternothyroid.
[Diagram]
All these muscles elevate the larynx except sternothyroid with depresses the larynx.

Further notes:
The term “salpingo” in salpingopharyngeus is of Greek origin, where it refers ot a tube or a tube-like structure. In the context of the salpingopharyngeus muscle, it refers to the auditory (Eustachian) tube, form which the muscle originates. This muscle aids in opening the auditory tube during swallowing.

Question 8

The intrinsic muscles of the larynx attach the laryngeal cartilages to each other and are responsible for their movements. State three general functions of intrinsic muscles of the larynx.

Answer 8

(a) to open or close the laryngeal inlet,
(b) to adduct and abduct the vocal cords, and
(c) to increase or decrease the tension of the vocal cords (cricothyroid muscle makes the vocal cords tense).

Question 9

Name the muscles that open or close the laryngeal inlet.

Answer 9

Those that close the inlet of the larynx:
oblique arytenoids, aryepiglotticus

Those that open the inlet of the larynx:
thyroepiglotticus

Question 10

Name the muscles that adduct or abduct the vocal cords.

Answer 10

Adduction: lateral cricoartyenoids, transverse arytenoid
Abduction: posterior cricoarytenoids

Question 11

Name the muscles that increase or decrease the tension of
vocal cords.

Answer 11

Increase: Cricothyroid, Vocalis
Decrease: Thyroarytenoid

Question 12

State the nerve supply of the intrinsic muscles of the larynx.

Answer 12

All the intrinsic muscles of the larynx are supplied by inferior laryngeal branch of recurrent laryngeal nerve except cricothyroid, which is supplied by the external laryngeal nerve, a branch of the superior laryngeal nerve.

Question 13

State the arterial supply of the larynx.

Answer 13

The arterial supply of larynx is as follows:
1. Above the vocal fold by superior laryngeal artery, a branch
of superior thyroid artery.
2. Below the vocal fold by inferior laryngeal artery, a branch
of inferior thyroid artery

Question 14

State the lymphatic drainage of the larynx.

Answer 14

Lymph from the larynx above the vocal cords drains into the upper deep cervical lymph nodes.
Lymph from the larynx below the vocal cords drains into the lower deep cervical lymph nodes.