10.1.1 Functional Anatomy of the Larynx

Question 1

What are the 4 functions of the layrnx?

Answer 1

• Airway Protection- prevents food/fluid entering airways
• Cough Reflex- rapidly expel anything inadvertently entering the airway
• Ventilation- movement of air in/out of lungs
• Phonation

Question 2

Where is the larynx suspended from?

Answer 2

Hyoid bone by supra-hyoids, therefore moves when hyoids move

Question 3

What is the Larynx?

Answer 3

Part of the upper respiratory tract, transmits air in/out of lower respiratory tract

Starts at laryngeal inlet, ends at lower border of cricoid cartilage (C6)

Question 4

What does the larynx continue as?

Answer 4

Trachea

Question 5

What does the larynx lie anterior to?

Answer 5

Laryngopharynx

Question 6

What are the piriform fossae?

Answer 6

Laryngopharynx presses against the pharynx to form these fossae

Allows drainage of fluid that collects here

Question 7

Label the image

Answer 7

Question 8

What are the cartilaginous structures in the larynx?

Answer 8

Epiglottis (sits at the top of the laryngeal inlet, not surround trachea)
Thyroid
Cricoid
Arytenoid (posterior to cricoid cartilage, rotates allowing vocal cords to move)

Question 9

What is the framework of the larynx?

Answer 9

Cartilages and connective tissue membranes (connect cartilages to one another, e.g. thyrohyoid membrane)

Question 10

What are the two synovial joints of the larynx?

Answer 10

Crico-thyroid[A]
Crico-arytenoid [F]

Question 11

What is the function of the Cricothyroid synovial joint?

Answer 11

• Allows Tilting
• Changes pitch of sound, tenses or relaxes vocal ligaments

Question 12

What is the function of the cricoid-arytenoid synovial joint?

Answer 12

• Allow rotation and sliding
• Open or close larynx (abduct or adducts vocal ligaments)

Question 13

Label the image

Answer 13

Question 14

What is the surface anatomy of the larynx?

Answer 14

Can feel the hyoid bone, able to move it from side to side

Laryngeal Prominence (Adam’s Apple) can usually be seen easily

Cricoid Cartilage below thyroid

Spongy, non-hard part between cricoid and thyroid is the cricothyroid membrane-cricothyroidotomy here

Question 15

What is a cricothyroidotomy and why do we do it?

Answer 15

Cut into cricothyroid membrane to provide emergency access to airway beneath vocal cords

Used if patient is in anaphylaxis, cannot intubate in time, laryngospasm or to buy some time before tracheostomy can be done

Question 16

What are the aryepiglottic folds?

Answer 16

Upper free edge of quadrangular membrane

Question 17

What are the margins of the laryngeal inlet?

Answer 17

• Aryepiglottic folds
• Upper edge of epiglottis

Question 18

What creates the false vocal cord?

Answer 18

Free Lower border of quadrangular membrane = vestibular ligament

Question 19

What creates the true vocal cord?

Answer 19

Free upper border of cricothyroid membrane = vocal ligament