Phonatory System Anatomy- Extrinsic Laryngeal Muscles

What do Extrinsic muscles change position of ?

larynx
- looks a bit forward vs backwards

What do intrinsic muscles change positions of?

shape of vfs (vocal folds)
- adducted (together) or abducted (apart)
-longer or shorter

What roles do the extrinsic (or supplementary) muscles play?

-provide support for larynx
- change position of larynx
- foundation for tongue & mandible movement

what is another name for extrinsic muscles?

supplementary muscles

Example of extrinsic muscles changing height & position of larynx (during swallowing)

Hyoid & Thyroid bone watch 03:48 of Extrinsic muscle ELC video
4:18 for pitch change: up in pitch- larynx came up closer to camera and backwards

What are the suprahyoid muscles and where are they generally located?

Above hyoid. digastric, stylohyoid, mylohyoid, geniohyoid

What are the infrahyoid muscles and where are they generally located?

Below hyoid. Sternothyroid, omohyoid, sternohyoid, , thyrohyoid

what are the roles of the suprahyoid muscles

raise larynx

Role of infrahyoid muscles

lower larynx

diagstric muscle (L.di=twice, gastric=belly)

two bellies: Anterior and posterior belly)

digastric anterior belly attachments

mandible, intermediate tendon of hyoid

diagastric anterior belly function

pull larynx (and also hyoid) up and forward (when it contracts).

digastric posterior belly attachments

intermediate tendon of hyoid and mastoid process of temporal bone

digastric posterior belly function:

pull hyoid/larynx up and back

Stylohyoid (L.stylo-pole) attachments

styloid process of temporal bone
hyoid bone

Stylohyoid function

pull hyoid/larynx up and back- when it contracts

Mylohyoid attachments

mandible, median raphe, hyoid bone

mylohyoid function

pulls hyoid/larynx up and forward

picture included in this is just another view of attachments of the mylohyoid (including the median raphe)

cadaver pic

geniohyoid attachments

madible and hyoid bone.

geniohyoid function

- pull hyod/larynx up and forward

note* for geniohyoid

it is deep to mylohoid so its visible only from above and not below

Sternohyoid attachments

sternum and hyoid bone

Sternohyoid function

pull hyoid/larynx down

sternothyroid attachments

sternum and thyroid

sternothyroid function

pull larynx down

Thyrohyoid attachments

hyoid and thyroid

Thyrohyoid function

pull hyoid up or down

Omohyoid (two bellies)

-inferior belly (also posterior belly)
-superior belly (also anterior belly)

Omohyoid attachments- superior belly

intermediate tendon and hyoid

Omohyoid attachments- inferior belly

scapula and intermediate tendon

Omohyoid inferior belly function

stiffen carotid sheath so blood vessels don't collapse during deep inhalation

cadaver view of omphyoid muscle and sheath

Omohyoid superior belly function

pull hyoid/larynx down

Summarize role of extrinsic muscles-suprahyoid muscles

- provide muscular framework for larynx
- raise larynx during swallowing
- help raise pitch
- also tongue and mandible movement

Summarize role of extrinsic muscles-infrahyoid muscles

-provide muscular support for larynx
- help lower pitch