laryng 2 Flashcards
Which pharyngeal arches do the laryngeal cartilages develop from?
4, 6
The laryngotracheal groove/inlet develops the ______ which grow towards the ______ (hypopharyngeal eminence) and form the T-shaped ______.
- Arytenoid swellings
- Tongue
- Laryngeal inlet
Which part of the hypopharyngeal eminence does the epiglottis develop from? Which arch is associated?
- Caudal part
- Arch 4
Which nerve is PA4 innervated by? Which muscles are associated?
- CN X (superior laryngeal branch of vagus nerve)
- Cricothyroid
Which nerve is PA6 innervated by? Which muscles are associated?
- CN X (recurrent laryngeal branch of vagus nerve)
- Intrinsic laryngeal muscles
What are the 2 categories of extrinsic larynx muscles?
- Elevators
- Depressors
What are the 4 categories of intrinsic larynx muscles?
- Adductors
- Abductors
- Pitch/tensor
- Epiglottis movers
What is the clinical importance of laryngeal elevation?
Decreases risk of aspiration
What are the 5 laryngeal elevators?
- Digastric (anterior and posterior belly)
- Stylohyoid
- Mylohyoid
- Geniohyoid
- Hyoglossus
Origin/insertion/innervation/action of anterior and posterior belly?
- Anterior: mandible / hyoid tendon / CN V (trigeminal)
- Posterior: mastoid / hyoid tendon / CN VII (facial)
- Action: pulls hyoid up to help swallow and open mouth
Origin/insertion/innervation/action of stylohyoid?
- Styloid process
- Hyoid bone
- CN VII (facial)
- Action: elevates hyoid
Origin/insertion/innervation/action of mylohyoid (fan)?
- Mandible
- Hyoid
- CN V (trigeminal)
- Opens jaw, elevates hyoid
Where do the two fans of the mylohyoid meet?
Median fibrous raphe
Origin/insertion/innervation/action of geniohyoid?
- Mandible
- Hyoid
- CN XII (hypoglossal)
- Opens jaw, elevates hyoid
What is the “sandwich” that makes the jaw?
- Anterior belly
- Mylohyoid (fan)
- Geniohyoid (twins)
- Genioglossus
- Tongue
(bottom to top)
Origin/insertion/innervation/action of hyoglossus?
- Hyoid
- Tongue
- CN XII (hypoglossal)
- Depresses tongue or elevates hyoid
When you say “ah” at the doctor and pull your tongue down flat and low, you are contracting the right and left _____
Hyoglossus
What are the 4 laryngeal depressors?
- Omohyoid
- Sternohyoid
- Thyrohyoid
- Sternothyroid
“three hyoids, one thyroid”
Origin/insertion/innervation/action of omohyoid?
- Scapula
- Hyoid
- C1-C3
- Depresses hyoid, pulls larynx down
3 parts of omohyoid?
- Inferior belly (o: scapula, i: tendon)
- Superior belly (o: tendon, i: hyoid)
- Intermediate tendon
Origin/insertion/innervation/action of sternohyoid?
- Manubrium (sternum) + sternoclavicular joint
- Hyoid
- C1-C3
- Depresses hyoid, pulls larynx down
Origin/insertion/innervation/action of sternothyroid?
- Manubrium (sternum)
- Thyroid cartilage
- C2-C3
- Depresses hyoid, pulls larynx down
Origin/insertion/innervation/action of thyrohyoid?
- Thyroid cartilage
- Hyoid
- C1
- Depresses and fixes hyoid and larynx + raises larynx during swallowing
How many extrinsic larynx muscles total?
9
How many intrinsic larynx muscles total?
8
Why are there more adductors than abductors? (2)
- Airway protection
- System is open at rest
2 parts of thyroarytenoid muscle + origin/insertion/action of each?
- Thyromuscularis: o = anterior commissure of thyroid cartilage, i = muscular process of arytenoids, action = VF adduction
- Thyrovocalis: o = anterior commissure of thyroid cartilage, i = vocal process of arytenoids, action = lowers pitch by making VFs less tense (thicker) when NOT counteracted by other muscles / raises pitch by making VFs more tense if counteracted by other muscles
Origin/insertion/action of cricothyroid?
- Cricoid
- Thyroid lamina
- Tensor: rotates thyroid cartilage, lengthens VFs (+tension)
- Changes pitch (big changes)
T or F: the thyrovocalis and cricothyroid work opposite of each other
true
Origin/insertion/action of the 2 parts of the interarytenoid muscle?
- Oblique fibres: o = arytenoid base, i = opposite arytenoid apex
- Transverse fibres: o = vertical length of arytenoid, i = vertical length of opposite arytenoid
Action: adductors (of arytenoids + VFs)
Are the oblique and transverse fibers paired or unpaired?
- Oblique = paired
- Transverse = unpaired
Origin/insertion/action of lateral cricoarytenoid (LCA)?
- Cricoid cartilage
- Muscular process of arytenoid cartilage
- Adductor (pulls muscular process anterolaterally + vocal process comes together, linking VFs)
Where is the LCA muscle located?
Arch of cricoid cartilage
Origin/insertion/action of posterior cricoarytenoid (PCA)?
- Cricoid lamina (posterior)
- Muscular process of arytenoid cartilage
- ONLY VF ABDUCTOR (moves vocal process laterally)
Origin/insertion/action of thyroepiglottic muscle?
- Thyroid cartilage
- Epiglottis + aryepiglottic fold
- Widens laryngeal vestibule (no effect on VFs)
Origin/insertion/action of aryepiglottic muscle?
- Arytenoid apex
- Lateral border of epiglottis/aryepliglottic fold
- Pulls epiglottis down to close airway
What is the space b/w the two VFs called? Where are they located in relation to the ventricular folds (false VFs)? What position are they in at rest?
- Glottis
- Inferior
- Abducted (for breathing)
5 layers of the VFs?
- Epithelium (basement membrane = adhesion protein zone)
- Superficial lamina propria (jelly)
- Intermediate lamina propria
- Deep lamina propria
- Vocalis muscle (stiffest)
What serves as the transition between the two outer layers of the VFs and the vocalis muscle?
Vocal ligament
List what nerves V, VII, X, XII, and C1-C3 innervate?
- 5: mylohyoid, digastric anterior
- 7: stylohyoid, digastric posterior
- 10: all other laryngeal muscles
- 12: geniohyoid, hyoglossus, thyrohyoid
- C1-C3: sternohyoid, sternothyroid, omohyoid
T or F: all larynx intrinsic muscles are innervated by CN XII
False – CN X (vagus)
3 branches of vagus nerve?
- Pharyngeal (motor, soft palate)
- Superior laryngeal (motor, cricothyroid + sensory, epiglottis, tongue, larynx)
- Recurrent laryngeal nerve (motor, intrisics except cricothyroid + sensory, subglottal structures)
