Sternothyroid muscle

Sternothyroid muscle
Sternothyroid muscle
	Sternothyroid visible center left
	Section of the neck at about the level of the sixth cervical vertebra. Showing the arrangement of the fascia coli. (Sternothyroideus labeled at right, third from top.)
Details
Origin	Manubrium
Insertion	Thyroid cartilage
Artery	Superior thyroid artery
Nerve	Ansa cervicalis
Actions	Depresses thyroid cartilage
Identifiers
Latin	musculus sternothyroideus
TA98	A04.2.04.006
TA2	2173
FMA	13343
	Anatomical terms of muscle [edit on Wikidata]

The sternothyroid muscle (or sternothyroideus) is an infrahyoid muscle of the neck.^[1] It acts to depress the hyoid bone.

Structure

The two muscles are in contact with each other proximally (close to their origin), but diverge distally (towards their insertions).^[1]

Origin

The sternothyroid arises from the posterior surface of the manubrium of the sternum from the midline to the notch for the first rib (inferior to the origin of the sternohyoid muscle), and the posterior margin of the first costal cartilage.^[1]

Insertion

It inserts onto the oblique line of the lamina of thyroid cartilage.^[1]

Innervation

The sternothyroid muscle receives motor innervation from branches of the ansa cervicalis (ultimately derived from cervical spinal nerves C1-C3).^[1]

Relations

The sternothyroid muscle is shorter and wider than the sternohyoid muscle and is situated deep to and partially medial to it.^[1]

Variations

The muscle may be absent or doubled. It may issue accessory slips to the thyrohyoid muscle, inferior pharyngeal constrictor muscle, or the carotid sheath.

Actions/movements

The sternothyroid muscle indirectly depresses the hyoid bone by means of pulling the thyroid. When the hyoid bone is fixed, it instead elevates the larynx (producing an increased voice pitch).^[1]

Clinical significance

The upward extension of a thyroid swelling (goitre) is prevented by the attachment of the sternothyroid to the thyroid cartilage. A goitre can therefore only grow to the front, back or middle but no higher.

Additional images

Superficial dissection of the right side of the neck, showing the carotid and subclavian arteries.
The fascia and middle thyroid veins.
Hypoglossal nerve, cervical plexus, and their branches.
Side view of the larynx, showing muscular attachments.
Sternothyroid muscle

References

This article incorporates text in the public domain from page 393 of the 20th edition of Gray's Anatomy (1918)

1 2 3 4 5 6 7 Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42th ed.). New York. p. 582. ISBN 978-0-7020-7707-4. OCLC 1201341621.{{cite book}}: CS1 maint: location missing publisher (link)

External links

Photo of model at Waynesburg College musclehead/sternothyroid
Anatomy photo:25:03-0105 at the SUNY Downstate Medical Center - "The Muscular triangle"
PTCentral

[:224-1] 1 2 3 4 5 6 7 Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42th ed.). New York. p. 582. ISBN 978-0-7020-7707-4. OCLC 1201341621.{{cite book}}: CS1 maint: location missing publisher (link)

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