Neck Muscles; Types, Classification, Function

The muscles that comprise the boundary of the posterior neck triangle in the sternocleidomastoid and trapezius muscles. The platysma muscle is found overlying the triangle superficially. Muscles coursing within the boundaries of the posterior neck triangle include the anterior, middle, and posterior scalene muscles as well as the omohyoid muscle. Superiorly, the semispinalis capitis and splenius capitis muscles insert near the apex of the junction of the sternocleidomastoid and trapezius muscles at the superior nuchal line of the occiput.[rx]

The Muscle of Neck and Head

• Clavicular Head of Sternocleidomastoid Muscle
• Depressor Anguli Oris Muscle
• Depressor Labii Inferioris Muscle
• Frontal Belly of Epicranius Muscle (Frontalis Muscle)
• Galea Aponeurotica
• Levator Labii Superioris Alaeque Nasi Muscle
• Levator Labii Superioris Muscle
• Levator Scapulae Muscle
• Masseter Muscle
• Mentalis Muscle
• Muscles of the Eye
• Muscles of the Tongue
• Nasalis Muscle
• Occipital Belly of Epicranius Muscle (Occipitalis Muscle)
• Omohyoid Muscle
• Orbicularis Oculi Muscle
• Orbicularis Oris Muscle
• Platysma Muscle
• Risorius Muscle
• Scalene Muscles
• Semispinalis Capitis Muscle
• Splenius Capitis Muscle
• Sternal Head of Sternocleidomastoid Muscle
• Sternohyoid Muscle
• Temporalis Muscle
• Trapezius Muscle
• Zygomaticus Major Muscle
• Zygomaticus Minor Muscle

Muscles Back

The muscles of the back subdivide into three categories.[rx] The first category is the superficial, or extrinsic, back muscles.[rx] These muscles are located posteriorly on the back, but they assist in movement of the limbs.[rx] The superficial muscles include

• Trapezius
• Latissimus dorsi
• Levator scapulae
• Rhomboids
• Serratus posterior inferior
• Serratus posterior superior
• Iliocostalis
• Longissimus
• Spinalis
• Semispinalis
• Multifidus
• Rotatores

Thoracic? Wall

• Anterior/Superficial Thorax
  • Pectoralis major and minor muscles
  • Subclavius
  • Serratus anterior
• Floor
  • Diaphragm

Several muscles should be considered when discussing neck and thyroid? surgical anatomy-

• Platysma – The first muscle encountered during neck dissection, it is enveloped by the superficial cervical? fascia. It sits in the anterior neck and extends from the superficial fascia of the deltoid, over the clavicle, reaching the mandible and superficial fascia of the face superiorly.
• Sternocleidomastoid – This muscle forms the anterior portion of the posterior triangle of the neck. The muscle runs obliquely from the mastoid to the clavicle and sternum. The sternocleidomastoid is found anterolaterally relative to the thyroid? gland.
• Digastric muscle – This muscle extends from the mandibular tubercle, passes deep and inferior to the hyoid, and loops back up to attach to the mastoid tip.
• Infrahyoid muscles – These are also referred to as “strap muscles.” They include four paired muscles found on the anterolateral surface of the thyroid? gland. The strap muscles result in gross movement of the larynx during swallowing and also adjust the positioning of the larynx during vocalization.
• Omohyoid muscle – The omohyoid muscle is found deep in the sternocleidomastoid. It extends from the hyoid bone to the lateral aspect of the clavicle.
• Sternohyoid muscle – This muscle sits anterior the remaining strap muscles and the thyroid? gland. The sternohyoid muscle extends from its superior attachment at the hyoid bone inferiorly to the sternum.
• Sternothyroid muscle – This muscle extends from the oblique line of the thyroid? cartilage? to the sternum. This muscle contacts the anterior surface of the thyroid gland.
• Thyrohyoid muscle – The thyrohyoid muscle extends from the oblique line of the thyroid? cartilage? to the hyoid bone superiorly.
•  Inferior pharyngeal constrictor – This muscle extends from its anterior attachment at the oblique line of the thyroid? cartilage? and lateral aspect of the cricoid cartilage to the pharyngeal raphe. This muscle contacts the superior pole of the lateral lobe of the thyroid gland medially.

Frequently Asking  Muscle of Face and Neck

• Anterior scalene – a muscle anterior to the middle scalene
• Appendicular – of the arms and legs axial of the trunk and head
• Buccinator – the muscle that compresses the cheek
• Corrugator supercilii – prime mover of the eyebrows
• Deglutition – swallowing
• Digastric – a muscle that has anterior and posterior bellies and elevates the hyoid bone and larynx when one swallows; it also depresses the mandible
• Epicranial aponeurosis – (also, galea aponeurosis) flat broad tendon? that connects the frontalis and occipitalis
• Erector spinae group – large muscle mass of the back; primary extensor of the vertebral column
• Extrinsic eye muscles – originate outside the eye and insert into the outer surface of the white of the eye, and create eyeball movement
• Frontalis – the front part of the occipitofrontalis muscle
• Genioglossus – the muscle that originates on the mandible and allows the tongue to move downward and forward
• Geniohyoid – the muscle that depresses the mandible, and raises and pulls the hyoid bone anteriorly
• Hyoglossus – a muscle that originates on the hyoid bone to move the tongue downward and flatten it
• Iliocostalis cervicis – the muscle of the iliocostalis group associated with the cervical? region
• Iliocostalis group – laterally placed muscles of the erector spinae
• Iliocostalis lumborum – the muscle of the iliocostalis group associated with the lumbar? region
• Iliocostalis thoracic? – the muscle of the iliocostalis group associated with the thoracic? region
• Infrahyoid muscles – anterior neck muscles that are attached to, and inferior to the hyoid bone
• Lateral pterygoid – the muscle that moves the mandible from side to side
• Longissimus capitis – the muscle of the longissimus group associated with the head region
• Longissimus cervicis – the muscle of the longissimus group associated with the cervical? region
• Longissimus group – intermediately placed muscles of the erector spinae
• Longissimus thoracis – the muscle of the longissimus group associated with the thoracic? region
• Masseter – main muscle for chewing that elevates the mandible to close the mouth
• Mastication – chewing
• Medial pterygoid – the muscle that moves the mandible from side to side
• Middle scalene – longest scalene muscle, located between the anterior and posterior scalenes
• Multifidus – the muscle of the lumbar? region that helps extend and laterally flex the vertebral column
• Mylohyoid – the muscle that lifts the hyoid bone and helps press the tongue to the top of the mouth
• Occipitalis – posterior part of the occipitofrontalis muscle
• Occipitofrontalis – the muscle that makes up the scalp with a frontal belly and an occipital belly
• Omohyoid – a muscle that has superior and inferior bellies and depresses the hyoid bone
• Orbicularis oculi – a circular muscle that closes the eye
• Orbicularis oris – a circular muscle that moves the lips
• Palatoglossus – the muscle that originates on the soft palate to elevate the back of the tongue
• Posterior scalene – smallest scalene muscle, located posterior to the middle scalene
• Scalene muscles – flex, laterally flex, and rotate the head; contribute to deep inhalation
• Segmental muscle group – interspinal and intertransversarii muscles that bring together the spinous and transverse processes of each consecutive vertebra
• Semispinalis capitis – transversospinales muscle associated with the head region
• Semispinalis services – transversospinales muscle associated with the cervical? region
• Semispinalis thoracic? – transversospinales muscle associated with the thoracic? region
• Spinalis capitis – the muscle of the spinal group associated with the head region
• Spinalis cervicis – the muscle of the spinal group associated with the cervical? region
• Spinalis group – medially placed muscles of the erector spinae
• Spinalis thoracis – the muscle of the spinal group associated with the thoracic? region
• Splenius – posterior neck muscles; includes the splenius capitis and splenius cervicis
• Splenius capitis – neck muscle that inserts into the head region
• Splenius cervicis – neck muscle that inserts into the cervical? region
• Sternocleidomastoid – the major muscle that laterally flexes and rotates the head
• Sternohyoid – a muscle that depresses the hyoid bone
• Sternothyroid – a muscle that depresses the larynx’s thyroid? cartilage?
• Styloglossus – a muscle that originates on the styloid bone, and allows upward and backward motion of the tongue
• Stylohyoid – a muscle that elevates the hyoid bone posteriorly
• Suprahyoid muscles – neck muscles that are superior to the hyoid bone
• Temporalis – a muscle that retracts the mandible
• Thyrohyoid – a muscle that depresses the hyoid bone and elevates the larynx’s thyroid? cartilage?
• Transversospinales – muscles that originate at the transverse processes and insert at the spinous processes of the vertebrae.

References