The infrahyoid muscles, or strap muscles, are a group of four pairs of

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of mus ...

s in the

anterior Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

(frontal) part of the

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

. The four infrahyoid muscles are the

sternohyoid The sternohyoid muscle is a thin, narrow muscle attaching the hyoid bone to the sternum. It is one of the paired strap muscles of the infrahyoid muscles. It is supplied by the ansa cervicalis. It depresses the hyoid bone. Structure The sternoh ...

sternothyroid The sternothyroid muscle, or sternothyroideus, is an infrahyoid muscle in the neck. It acts to depress the hyoid bone. It is below the sternohyoid muscle. It is shorter and wider than the sternohyoid. Structure The sternothyroid arises from the ...

thyrohyoid The thyrohyoid muscle is a small skeletal muscle on the neck. It originates from the lamina of the thyroid cartilage, and inserts into the greater cornu of the hyoid bone. It is supplied by the hypoglossal nerve, and a branch of the ventral rami o ...

and

omohyoid muscle The omohyoid muscle is a muscle that depresses the hyoid. It is located in the front of the neck, and consists of two bellies separated by an intermediate tendon. The omohyoid muscle is proximally attached to the scapula and distally attached to t ...

s. Excluding the sternothyroid, the infrahyoid muscles either originate from or

insert Insert may refer to: *Insert (advertising) *Insert (composites) *Insert (effects processing) *Insert (filmmaking) *Insert key on a computer keyboard, used to switch between insert mode and overtype mode *Insert (molecular biology) *Insert (SQL) *Fi ...

on to the hyoid bone. The term ''infrahyoid'' refers to the region below the

hyoid bone The hyoid bone (lingual bone or tongue-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 between the base of the mandible and the third cervical verteb ...

, while the term strap muscles refers to the long and flat muscle shapes which resembles a

strap A strap, sometimes also called strop, is an elongated flap or ribbon, usually of leather or other flexible materials. Thin straps are used as part of clothing or baggage, or bedding such as a sleeping bag. See for example spaghetti strap, ...

. The

stylopharyngeus The stylopharyngeus is a muscle in the head that stretches between the temporal styloid process and the pharynx. Structure The stylopharyngeus is a long, slender muscle, cylindrical above, flattened below. It arises from the medial side of the ...

muscle is considered by many to be one of the strap muscles, but is not an infrahyoid muscle.

Individual muscles

The

origin Origin(s) or The Origin may refer to: Arts, entertainment, and media Comics and manga * Origin (comics), ''Origin'' (comics), a Wolverine comic book mini-series published by Marvel Comics in 2002 * The Origin (Buffy comic), ''The Origin'' (Bu ...

insertion Insertion may refer to: * Insertion (anatomy), the point of a tendon or ligament onto the skeleton or other part of the body * Insertion (genetics), the addition of DNA into a genetic sequence *Insertion, several meanings in medicine, see ICD-10-PC ...

and

innervation A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the ...

of the individual muscles:

Nerve supply

All of the infrahyoid muscles are innervated by the

ansa cervicalis The ansa cervicalis (or ansa hypoglossi in older literature) is a loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid triangle. Its name means "handle of the neck" in Latin. Bra ...

from the

cervical plexus The cervical plexus is a plexus of the anterior rami of the first four cervical spinal nerves which arise from C1 to C4 cervical segment in the neck. They are located laterally to the transverse processes between prevertebral muscles from the me ...

( C1- C3) except the thyrohyoid muscle, which is innervated by fibers only from the first cervical spinal nerve travelling with the

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated ...

Function

The infrahyoid muscles function to elevate and depress the hyoid bone and

larynx The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...

during

swallowing Swallowing, sometimes called deglutition in scientific contexts, is the process in the human or animal body that allows for a substance to pass from the mouth, to the pharynx, and into the esophagus, while shutting the epiglottis. Swallowing i ...

and speech. This moves the larynx as one unit.

References

{{DEFAULTSORT:Infrahyoid Muscles Muscles of the head and neck

Individual muscles

Nerve supply

Function

See also

References