answers
extrinsic laryngeal muscle function - correct answer ✔✔Elevate the larynx within the vocal tract -
Suprahyoid extrinsic muscles
Laryngeal depression - Infrahyoid extrinsic muscles
suprahyoid muscles include - correct answer ✔✔digastric, stylohyoid, mylohyoid, geniohyoid
suprahyoid muscle function - correct answer ✔✔elevate hyoid and larynx
Digastric - correct answer ✔✔Anterior belly pulls the hyoid forward and upward
Posterior belly pulls the hyoid back and upward
Mylohyoid - correct answer ✔✔elevate floor of mouth & tongue; depresses jaw if hyoid is stabilized
Stylohyoid - correct answer ✔✔pulls hyoid forward & back; fixes hyoid bone for infrahyoid action during
swallowing
Geniohyoid - correct answer ✔✔elevates hyoid; raises floor of mouth for swallowing; depresses
mandible if hyoid is stabilized
Infrahyoid muscle function - correct answer ✔✔depresses hyoid & larynx; jaw movement
Infrahyoid muscles include - correct answer ✔✔Sternohyoid
Sternothyroid
Omohyoid
Thyrohyoid
,Sternohyoid - correct answer ✔✔attaches hyoid bone to larynx; depresses hyoid bone and larynx
Sternothyroid - correct answer ✔✔depresses larynx
Omohyoid - correct answer ✔✔depresses and retracts hyoid bone & depresses larynx
thryohyoid - correct answer ✔✔moves hyoid bone closer to the larynx
intrinsic laryngeal muscle function - correct answer ✔✔movement of laryngeal cartilages & finer control
of layneal structures; regulate tension of vocal ligament & size/shape of glottal space
intrinsic laryngeal muscle innervation - correct answer ✔✔CN X (vagus)
Intrinsic laryngeal muscles include - correct answer ✔✔Thyroarytenoid muscle (TA)
Posterior cricoarytenoid muscle (PCA)
Lateral cricoarytenoid muscle (LCA)
Interarytenoid muscles (IA)
Cricothyroid muscle (CT)
Thyroarytenoid muscle (TA) - correct answer ✔✔shortens VFs
deepest layer of VF structure
2 sections:
1. thyrovocalis = more medial; tenses VFs
2. thyrmuscularis = more lateral; relaxes VFs
Posterior cricoarytenoid muscle (PCA) - correct answer ✔✔abducts VFs by moving muscular process
medically & rotating vocal processes laterally
, Lateral cricoarytenoid muscle (LCA) - correct answer ✔✔adducts VFs by moving muscular process
posterolaterally & vocal process medially
Interarytenoid muscles (IA) - correct answer ✔✔obligue & transverse fibers; both fibers adduct VFs
Cricothyroid muscle (CT) - correct answer ✔✔changes pitch (thyroid pulled down, increases VF length &
tension)
Innvervated by superior laryngeal nerve of CN X
muscles of inspiration - correct answer ✔✔Diaphragm
External Intercostal Muscles
Accessory muscles
Diaphragm - correct answer ✔✔major muscle of inspiration; dome-shaped at rest; moves downward &
flattens during inspiration; plays a major role in breathing, as its contraction increases the volume of the
thorax and so inflates the lungs
innvervation = phrenic nerves
external intercostal muscles - correct answer ✔✔muscles between ribs
elevate & expand ribcage, decreasing pressure inside chest cavity
increases size of chest cavity to allow for inspiration
Accessory muscles of inspiration - correct answer ✔✔muscles in trunk & lower neck that can assist with
respiration (deep & rapid breathing)
e.g., sternocleidomastoid and scalene muscles
muscles of expiration - correct answer ✔✔internal intercostals and abdominal muscles