Unit 4 - Head and Neck: Infrahyoid Muscles (Ex. III)

Question 1

sternohyoid

Answer 1

O: manubrium and P surface of SC joint
I: body of hyoid bone
Inn: ansa cervicalis of C plexus (C1-C3)
A: depresses (fixes) hyoid; draws larynx and hyoid down for phonation and terminal phases of swallowing

Question 2

sternothyroid

Answer 2

O: P surface of manubrium
I: oblique line of thyroid cartilage
Inn: ansa cervicalis (C2-C3)
A: depresses (fixes) hyoid; draws larynx and hyoid down for phonation and terminal phases of swallowing

Question 3

thyrohyoid

Answer 3

O: oblique line of thyroid cartilage
I: body of hyoid bone
Inn: C1 via hypoglossal n. (CN XII)
A: depresses and fixes hyoid; raises larynx during swallowing

Question 4

omohyoid

Answer 4

O: S border of scapula
I: body of hyoid bone
Inn: ansa cervicalis of C plexus (C1-C3)
A: depresses (fixes) hyoid; draws larynx and hyoid down for phonation and terminal phases of swallowing; tenses C fascia w/ an intermediate tendon