Anatomy and Disorders of the Larynx

Question 1

Where is the larynx located?

Answer 1

Between the hyoid bone above and the trachea below

C4-C6

Question 2

What is the function of the larynx?

Answer 2

Ventilation

Airway protection = prevents aspiration

Allows us to cough

Sound prod = phonation

Question 3

Name the 3 zones of the larynx

Answer 3

Supraglottis= from epiglottis to false vocal cords

Glottis = between false and true vocal cords

Infraglottis = between the true vocal cords and first tracheal ring

Question 4

What makes up the structural framework of the larynx?

Answer 4

Epiglottis cartilage

Thyroid cartilage

Cricoid cartilage

Arytenoid cartilage

Question 5

How is the thyroid cartilage attached to the hyoid bone?

Answer 5

Thyrohyoid membrane

Question 6

How is the thyroid cartilage attached to the cricoid cartilage?

Answer 6

Cricothyroid membrane

Question 7

What connects the cricoid cartilage to the first ring?

Answer 7

Cricotracheal membrane

Question 8

Why is the cricoid cartilage special?

Answer 8

Only complete cartilage ring in the resp tract

Question 9

How is the epiglottis attached to the inner surface of the thyroid cartilage?

Answer 9

Ligaments

Question 10

Describe the arytenoid cartilages

Answer 10

Paired

Sit atop the cricoid cartilage

Determine the position of the true vocal cords

Question 11

How does the thyroid cartilage articulate with the cricoid cartilage?

Answer 11

Synovial joint = movement

Question 12

Trough what membrane is the airway accessed during emergency?

Answer 12

Cricothyroid mem

Between the cricoid cartilage and thyroid cartilage

Question 13

Describe the location of the quadrangular mem and what it forms

Answer 13

Connects epiglottis to arytenoid cartilage and inner surface of the thyroid cartilage

Superior border forms = aryepiglottic folds = margins of oval inlet of larynx

Inferior border forms = vestibular ligament = false vocal cords

Question 14

What does the larynx lie anterior to?

Answer 14

Laryngopharynx

Question 15

What does the aryepiglottis fold form?

Answer 15

Margins of oval inlet of the larynx

Question 16

What name is given to the entrance of the larynx?

Answer 16

Aditus

Question 17

What forms the vocal ligament (true vocal cord)?

Answer 17

Thickening of the upper edge of the cricothyroid membrane

Question 18

What forms the false vocal ligament?

Answer 18

Vestibular ligament

Question 19

What forms the true vocal ligament?

Answer 19

Vocal ligament

Question 20

Name the space between the true vocal cords

Answer 20

Rima glottidis

Question 21

Outline the functions of the muscles of the larynx

Answer 21

Inspiration = open glottis

Swallowing = close vestibule and vocal cords

Phonation = alter tone of true vocal cords

Question 22

Where is the cricothyroid muscle located?

Answer 22

Only intrinsic muscle of the larynx found outside of the larynx

Question 23

Outline the nervous supply of the cricothyroid muscle

Answer 23

External laryngeal nerve = branch of the superior laryngeal nerve (branch of CN X).

Question 24

Which nerve innervates the laryngeal mucosa?

Answer 24

Internal laryngeal N = mucosa above the vocal cords

Recurrent laryngeal N = mucosa below the vocal cords

Question 25

Having a horse voice is a cardinal sign of what?

Answer 25

Laryngeal disease

Question 26

Why does damage of the laryngeal nerve cause a horse voice?

Answer 26

Unilateral complete injury = affected side takes up neutral position (paramedian), unaffected partially compensates, resulting in some horseness Both sides completely damaged = both vocal cords assume paramedian position = rima glottidis extremely narrow, resulting in diff breathing, speaking, coughing

Question 27

What type of ep lines the larynx?

Answer 27

Pseudostratified ciliated columnar ep

Question 28

What type of ep lines the true vocal cords?

Answer 28

Stratified squamous ep

Question 29

In what direction does the rima glottidis point?

Answer 29

Anterior

Question 30

When do the vocal cords ABduct?

Answer 30

Inspiration/expiration

Question 31

When do the vocal cords ADduct?

Answer 31

Phonation

Question 32

What structure determines the position of the true vocal cords?

Answer 32

Position of the arytenoids

Question 33

What is the function of the cricothyroid muscle?

Answer 33

Bilateral contraction increases length and tension in vocal cords = important in high pitch noise Tilts thyroid cartilage forward on cricoid = increasing tension in vocal cords = ADducting the vocal cords

Question 34

Why does damage to the external laryngeal nerve cause a horse voice?

Answer 34

No nervous supply to the cricothyroid = no contraction of the vocal cords = especially hard to make high-pitched sounds

Question 35

Outline the nerve supply to the larynx

Answer 35

Superior laryngeal nerve (branch of vagus) 1) Internal branch = sensory to supraglottic 2) External branch = motor to cricothyroid Recurrent laryngeal N (branch of vagus) = all intrinsic muscles of larynx + sensory to infraglottic

Question 36

What muscle contracts during swallowing and what does this result in?

Answer 36

Contraction of aryepiglottic muscles = narrow laryngeal inlet + pulls down epiglottis

Question 37

What can cause vocal cord palsies?

Answer 37

Aortic arch aneurysm = L RLN Cancer involving the apex of the lung (pancoast tumour) = R RLN Disease/surgery involving larynx, oesophagus, thyroid

Question 38

What nerve innervates the intrinsic muscles of the larynx?

Answer 38

Recurrent laryngeal nerve One exception = cricothyroid muscle (external laryngeal N)

Question 39

Describe croup

Answer 39

Parainfluenza = 80% of cases Viral upper resp tract infection = nasopharynx inflam Inflam may spread to the larynx and trachea = subglottal inflam Harsh barking cough

Question 40

What is epiglottitis

Answer 40

Inflam of the epiglottis Life-threatening if complete obstruction of the airway occurs Streptococcus Present = sore throat, pain/diff swallowing, fever, tachycardia

Question 41

Outline the location of the cervical plexus

Answer 41

posterior triangle of the neck, halfway up the SCM, and within the prevertebral layer of cervical fascia anterior rami (divisions) of cervical spinal nerves C1-C4

Question 42

Outline the relationship between the blood supply of the thyroid gland and the nerves supplying the larynx

Answer 42

Superior thyroid A runs next to the external branch of the superior laryngeal N recurrent laryngeal runs behind the thyroid gland both can be damaged due to surgery of the thyroid