Infrahyoid
Encyclopedia
The infrahyoid muscles are a group of four pairs of muscle
s in the anterior part of the neck
. (The term infrahyoid refers to the region below (inferior) to the hyoid bone in the neck
. )
Collectively, they are referred to as the strap muscles, because the muscles are long and flat much like a strap
.
from the cervical plexus(C1-3) EXCEPT for the thyrohyoid muscle, which is innervated by only C1.
The stylopharyngeus muscle is considered by many to be one of the strap muscles, but it is innervated by CN IX rather than the ansa cervicalis.
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s in the anterior part of the neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
. (The term infrahyoid refers to the region below (inferior) to the hyoid bone in the neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
. )
Collectively, they are referred to as the strap muscles, because the muscles are long and flat much like a strap
Strap
A strap, sometimes also called strop, is an elongated flap or ribbon, usually of fabric or leather.Thin straps are used as part of clothing or baggage, or bedding such as a sleeping bag. See for example spaghetti strap, shoulder strap...
.
Individual muscles
Namely, the muscles are:| Muscle | Origin | Insertion | Innervation >- | sternothyroid Sternothyroid muscle The Sternothyreoideus is shorter and wider than the Sternohyoideus, beneath which it is situated.It arises from the posterior surface of the manubrium sterni, below the origin of the Sternohyoideus, and from the edge of the cartilage of the first rib, and sometimes that of the second rib, it is... |
sternum | thyroid cartilage Thyroid cartilage The thyroid cartilage is the largest of the nine cartilages that make up the laryngeal skeleton, the cartilage structure in and around the trachea that contains the larynx.... |
ansa cervicalis Ansa cervicalis The ansa cervicalis is a loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid sheath.... >- | sternohyoid Sternohyoid muscle The sternohyoid muscle is a thin, narrow muscle attaching the hyoid bone to the sternum, one of the paired strap muscles of the infrahyoid muscles serving to depress the hyoid bone... |
sternum | hyoid bone Hyoid bone The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly... |
ansa cervicalis Ansa cervicalis The ansa cervicalis is a loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid sheath.... >- | thyrohyoid Thyrohyoid muscle The Thyrohyoid muscle is a small, quadrilateral muscle appearing like an upward continuation of the Sternothyreoideus. It belongs to the infrahyoid muscles group.... |
thyroid cartilage Thyroid cartilage The thyroid cartilage is the largest of the nine cartilages that make up the laryngeal skeleton, the cartilage structure in and around the trachea that contains the larynx.... |
hyoid bone Hyoid bone The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly... |
C1 Cervical spinal nerve 1 The cervical spinal nerve 1 is a spinal nerve of the cervical segment..It originates from the spinal column from above the cervical vertebra 1 .Muscles innervated by this nerve are:*Geniohyoid muscle- through Hypoglossal nerve... (via CN XII) Hypoglossal nerve The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal... >- | omohyoid (superior belly) Omohyoid muscle The omohyoid muscle is a muscle at the front of the neck that consists of two bellies separated by an intermediate tendon. It belongs to the group of infrahyoid muscles... |
intermediate tendon | hyoid bone Hyoid bone The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly... |
superior root of ansa cervicalis Superior root of ansa cervicalis The superior root of the ansa cervicalis is formed by branches of spinal nerves [Cervical spinal nerve 1 and 2 ].These nerve fibers travel in the hypoglossal nerve before separating in the carotid triangle to form the superior root.... >- | omohyoid (inferior belly) Omohyoid muscle The omohyoid muscle is a muscle at the front of the neck that consists of two bellies separated by an intermediate tendon. It belongs to the group of infrahyoid muscles... |
superior border of scapula Superior border of scapula Of the three borders of the scapula, the superior border is the shortest and thinnestit is concave, and extends from the medial angle to the base of the coracoid process.... |
intermediate tendon | ansa cervicalis Ansa cervicalis The ansa cervicalis is a loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid sheath.... |
Innervation
All of the infrahyoid muscles are innervated by ansa cervicalisAnsa cervicalis
The ansa cervicalis is a loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid sheath....
from the cervical plexus(C1-3) EXCEPT for the thyrohyoid muscle, which is innervated by only C1.
The stylopharyngeus muscle is considered by many to be one of the strap muscles, but it is innervated by CN IX rather than the ansa cervicalis.