The larynx

Question 1

What is the only complete circle of cartilage around the respiratory inlet?

Answer 1

The cricoid cartilage

Question 2

What are the two functions of the larynx?

Answer 2

Production of voice

Acts as valve to prevent food and foreign bodies entering lower respiratory passages

Question 3

How does the larynx vary between men and women?

Answer 3

Larynx is shorter in females

Question 4

Where is the laryngopharynx found?

Answer 4

Behind the larynx, infront of C4-6 vertebrae

Question 5

What is the inferior cornu and what does it articulate with?

Answer 5

Part of thyroid cartilage that forms synovial joint with cricoid cartilage

Question 6

How is the epiglottis attached to the tongue?

Answer 6

By a median and two lateral glosso-epiglottic folds

On either side is the valleculae

Question 7

How is the epiglottis attached to the arytenoid cartilages?

Answer 7

Aryepiglottic folds on the side

Form the lateral margins of the laryngeal inlet

Question 8

What are the two processes of the arytenoids called?

Answer 8

Muscular and vocal processes

Question 9

What is the slit between the two vocal cords called? Function?

Answer 9

The rima glottis,

Acts as a sphincter in coughing and sneezing

Question 10

Where are the vocal folds found?

Answer 10

Attached between vocal processes of arytenoids and thyroid cartilage

Question 11

What is the quadrangular membrane?

Answer 11

Fibroelastic membrane between epiglottis and arytenoids, thickened below to form vestibular ligament (false vocal cord)

Question 12

Where do objects get stuck in the larynx?

Answer 12

In the space lateral to the aryepiglottic folds (Piriform fossa)

Question 13

What is the lower border of the larynx?

Answer 13

The lower border of the cricoid cartilage, turns into trachea

Question 14

How does the mucosa of the vocal folds differ from the rest of the larynx?

Answer 14

Over the vocal folds it is keratinized stratified squamous epithelium, the rest of the larynx is respiratory (ciliated pseudostratified columnar epithelium w/mucous glands)

Question 15

Which muscles work by rotating arytenoids?

Answer 15

Lateral and posterior cricoarytenoid

Question 16

What is the action and innervation of the lateral cricoarytenoid?

Answer 16

Closes glottis through medial rotation of arytenoids

Recurrent laryngeal nerve

Question 17

What is the action and innervation of the posterior cricoarytenoid?

Answer 17

Separates vocal processes and cords by lateral rotation of arytenoids
Recurrent laryngeal nerve

Question 18

What is the action and innervation of cricothyroid muscle?

Answer 18

Tightens vocal cords by rotating thyroid cartilage downwards and forward
External laryngeal nerve

Question 19

What is the action and innervation of the vocalis muscle?

Answer 19

Regulates tension of vocal cords

Recurrent laryngeal nerve

Question 20

What is the action and innervation of the transverse arytenoid muscle?

Answer 20

Closes posterior part of rima glottis

Recurrent laryngeal nerve

Question 21

What is the action and innervation of the oblique arytenoid muscle?

Answer 21

Closes rima glottis

Recurrent laryngeal nerve

Question 22

What is the sensory supply of the laryngeal membrane?

Answer 22

Above vocal folds= internal branch of superior laryngeal nerve
Below vocal folds- recurrent laryngeal

Question 23

What is the blood supply of the larynx?

Answer 23

Superior and inferior thyroid arteries

Question 24

Name 5 possible reasons for a hoarse voice

Answer 24

Swollen vocal cords from infection, bilateral paralysis of cricoarytenoids, laryngeal tumours and severe dental infections

Question 25

How is the frequency of sound produced by the vocal cords change?

Answer 25

By the length and tension of the vocal cords when vibrated and by mass of vocal cords

Question 26

What innervation is needed for clear speech?

Answer 26

Vagus (vocal fold tension), facial (motor), trigeminal (sensory face and tongue), glossopharyneal (sensory tongue), hypoglossal (motor tongue)

Question 27

What muscles oppose the actions of the mylohyoid and geniohyoid?

Answer 27

Infrahyoid muscles- thyrohyoid, omohyoid and sternohyoid

Question 28

What muscles are involved in elevation of the tongue?

Answer 28

Styloglossus and palatoglossus

Question 29

What would be the effects of injury to the sympathetic trunk in the neck?

Answer 29

Horner’s syndrome

Ipsilateral pupil constriction, ptosis (droopy eyelid), dry forehead

Question 30

What symptoms would someone with a completely damaged vagus nerve have?

Answer 30

Palipitation, constant vomiting, feeling of suffocation