3.13 Larynx

Question 1

Describe Surface Anatomy larynx

Answer 1

1. Boundaries base tongue
   Superiorly extending to cricoid cartilage inferiorly
2. Opposite C3-6 male
   smaller and cephalad in women

3. Hyoid bone
U shaped bone
2 posterior horns
articulating w/ mandible
Adjacent to C3 vertebral body

Question 2

Cartilages

Answer 2

6 cartilages articulating with each other
functional larynx

1. Epiglottis
   U shaped structure
   base tongue
2. Thyroid cartilage

Question 3

2. Thyroid cartilage

Answer 3

Pair
Large square cartilages
join in middle = Adams apple

Lied below hyoid bone
connected by thyrohyoid membrane
Pierced by superior laryngeal vessels
internal branch of SLN

Articulates w/ cricoid cartilage inf
via cricothyroid membrane

Question 4

3. Cricoid cartilage

Answer 4

Complete cartilage ring

Wider posteriorly

Articulates w. Thyroid and arytenoid cartilages

Question 5

4. Arytenoid Cartilage

Answer 5

Pyramid shaped pair cartilages

Smooth base
articulates w. Cricoid cartilage

Anterior process
attaches to vocal folds

Posterior muscular process

Apex articulates w/ corniculate cartilages

Question 6

5. Corniculate Cartilage

Answer 6

Pair cartilages
Lie @ Apex of arytenoids
Tubercles in posterior aryepiglottic folds

Question 7

6. Cuneiform cartilage

Answer 7

Like in front of corniculate

Question 8

Muscles

Answer 8

1. Extrinsic muscles

2. Intrinsic

Question 9

1. Extrinsic muscles

Answer 9

Anchoring larynx to adjacent structures
Sternothyroid
Thyrohyoid
Inferior pharyngeal constrictors

Question 10

2. Intrinsic

Answer 10

Responsible for manipulation of VC phonation and coughing

1. Abduction - cords apart
   Posterior cricoarytenoid
2. Adduction - cords midline
   Lateral cricoarytenoids
   unpaired
   inter-arytenoid muscles
3. Cord tensors
   cricothyroid
   only intrinsic muscle outside larynx
   only muscle supply external branch of SLN
4. Cord relaxers
   Thyroarytenoid muscles
   Vocalis

Question 11

Nerve supply

Answer 11

Vagus Nerve
divides into
Superior and recurrent laryngeal

1. Superior Laryngeal N.
   Internal L N
   Inferior epiglottis
   sensation above cords

External N
Supplies motor to cricothyroid muscle

Recurrent Laryngeal
Below cords
Motor to remaining intrinsic muscles