Dominic Stone
The neck is home to more than 20 muscles that work to keep the head supported and enable movement. These muscles are divided into three categories: anterior, lateral, and posterior neck muscles. The anterior neck muscles are further divided into three subgroups: superficial muscles, suprahyoid muscles, and infrahyoid muscles. The lateral neck muscles consist of five muscles that help in moving the head and contracting the neck. The posterior neck muscles are also grouped into three: superficial muscles, suboccipital muscles, and transversospinalis muscles. The neck region is also where muscles of the head, spine, and thorax attach.
| Characteristics | Values |
|---|---|
| Number of neck muscles | 20+ |
| Muscle groups | 3-4 |
| Muscle functions | Supporting and stabilising the neck, moving the head in all directions, swallowing, chewing, speaking, breathing, protecting fragile structures, rotating the head, extending the neck, flexing the neck, elevating the sternum and clavicle, expanding the thoracic cavity, depressing the hyoid bone and larynx, opening the laryngeal inlet, pulling the thyroid cartilage away from the hyoid bone |
| Ligaments | Anterior longitudinal ligament (ALL), Posterior longitudinal ligament (PLL), Ligamentum flava |
| Arteries | Vertebral artery, Subclavian artery, Basilar artery |
Explore related products
What You'll Learn
Sternocleidomastoid
The sternocleidomastoid (SCM) is a powerful neck muscle that allows you to bend your neck and turn or tilt your head. It is one of the largest and most superficial cervical muscles, and it is located just below your skin on both sides of the neck. The SCM has dual innervation and multiple functions, and it acts in concert with the entire muscular group of the cervicofacial region. The SCM is innervated by the accessory nerve (CN XI) and anterior rami of spinal nerves C2 and C3. The SCM extends from the mastoid process at the base of the skull down both sides of the neck until it reaches the sternum (sternal head) or clavicle (clavicular head).
The function of the SCM depends on whether it acts alone or with its counterpart on the other side. A unilateral contraction produces a lateral flexion of the neck on the same side and a lateral rotation of the head to the opposite side. A bilateral contraction of the SCM produces a flexion of the neck, drawing the head towards the chest. When the head and neck are fixed, the SCM can also elevate the sternum and clavicle, expanding the thoracic cavity during forced inspiration.
The SCM is susceptible to strain and injury, which can lead to pain and stiffness. SCM-related issues include torticollis (wry neck), temporomandibular joint disorders (TMD), and sternocleidomastoid syndrome, which involves neck stiffness, pain, and trigger points. Treatment for SCM issues includes stretching, physical therapy, osteopathic manipulation, and surgery in severe cases.
The SCM is an important anatomical landmark within the neck region, dividing the neck into anterior and posterior triangles. It is also related to other important structures, including the common carotid artery, accessory nerve, and brachial plexus.
The Muscular Might of Snakes: Unraveling the Mystery
You may want to see also
Explore related products
Trapezius
The trapezius muscle is a large, paired trapezoid-shaped muscle that starts at the base of the neck and extends across the shoulders and down to the middle of the back. The muscle gets its name from its shape, resembling a trapezium or diamond-shaped quadrilateral. The trapezius is made up of long muscle fibres that span a large width of the upper back, enabling it to assist in postural attributes and allow the spinal column to remain erect when a person is standing.
The trapezius muscle has three sections: the upper, middle, and lower sections. The upper section connects to the skull and neck (cervical spine), while the middle and lower sections attach to the bones in the thoracic spine. The trapezius is also connected to the lateral sides of the shoulder blade (scapula) and collarbone (clavicle). The upper fibres elevate the scapulae, the middle fibres retract the scapulae, and the lower fibres depress the scapulae. The trapezius works in conjunction with several muscles to produce coordinated movements, primarily involving the scapula.
The trapezius muscle is crucial for maintaining scapular stability and allowing the shoulder to move efficiently during various activities such as pushing, reaching forward, or pulling down. It also assists in abduction of the shoulder by rotating the glenoid upward. The trapezius is involved in many daily motions, including turning the head to either side, maintaining and adjusting posture, twisting the torso, shrugging the shoulders, and moving the shoulder when lifting the arm or throwing something.
Injuries to the trapezius muscle can result in pain in the back, neck, or the back of the head. Common causes of trapezius muscle pain include overuse, injuries, and nerve damage. Stress can also lead to trapezius pain, as it can cause individuals to unconsciously squeeze their muscles, particularly in the shoulders, upper back, and neck. Symptoms of trapezius issues can include limited mobility, decreased range of motion, muscle weakness, neck and shoulder stiffness, and swelling or tenderness in the shoulders, neck, or back.
The Pecs Factor: Understanding Breast Muscle Sensations
You may want to see also
Explore related products
Erector spinae
The neck is comprised of several muscles that enable the movement of the head in all directions. The erector spinae (ES) is a large and superficial muscle that lies just deep to the thoracolumbar fascia and arises from the erector spinae aponeurosis (ESA). The ESA is a common aponeurosis that blends with the thoracolumbar fascia, with a proximal attachment to the sacrum and the spinous processes of the lumbar vertebrae. The erector spinae muscles are divided into three groups, from medial to lateral: spinalis, longissimus, and iliocostalis.
The spinalis muscles are the most medial erector spinae muscles and are divided into three regional groups, from superior to inferior: spinalis capitis, spinalis colli, and spinalis thoracis. The spinalis capitis is an inconstant muscle fibre that runs from the cervical and upper thoracic and inserts into the external occipital protuberance. The spinalis colli originates from the spinous processes of C7-T1 vertebrae and the nuchal ligament, inserting into the spinous processes of C2-C4 vertebrae. The spinalis thoracis originates from the spinous process of T11-L2 vertebrae and extends to the spinous process of T2-T8 vertebrae. The spinalis muscles are innervated by the lateral branches of the posterior rami of the cervical, thoracic, and lumbar spinal nerves, receiving blood supply from the vertebral, deep cervical, occipital, intercostal, and lumbar arteries. Their function is to extend and laterally flex the cervical and thoracic regions of the spine.
The longissimus muscles are the central erector spinae muscles and are also the thickest and longest. Similar to the spinalis muscles, they are divided into three regional groups, from superior to inferior: longissimus capitis, longissimus colli, and longissimus thoracis. The longissimus capitis originates from the transverse processes of vertebrae C4-T5 and inserts into the mastoid process of the temporal bone. The longissimus colli extends between the transverse processes of vertebrae T1-T5 and C2-C6. The longissimus thoracis consists of thoracic and lumbar parts, with the thoracic part travelling from the L1-L5 vertebrae, sacrum, and posterior iliac crest to the thoracic vertebrae and inferior six ribs, while the lumbar part extends between the region surrounding the anteromedial aspect of the ilium and L1-L5 vertebrae. The longissimus muscles have identical innervation to the spinalis muscles, receiving arterial blood from branches of the vertebral, deep cervical, occipital, transverse cervical, intercostal, and sacral arteries. Their function is to extend and laterally flex the spine, with the longissimus capitis also aiding in rotating the head ipsilaterally.
The iliocostalis muscles are the most lateral erector spinae muscles and are regionally divided into three groups, from superior to inferior: iliocostalis colli, iliocostalis thoracis, and iliocostalis lumborum. The iliocostalis colli originates from the angle of ribs 3 to 6 and inserts into the transverse processes of vertebrae C4-C6. The iliocostalis thoracis originates from the sacrum, erector spinae aponeurosis, and iliac crest, while the iliocostalis lumborum originates from the erector spinae aponeurosis and iliac crest. The erector spinae muscles play a crucial role in spinal stability, and their contraction helps to compensate for delays in increasing the stiffness of the lumbar spine.
Muscle Movement Mechanics: Understanding the Science of Bending
You may want to see also
Explore related products
Anterior neck muscles
The neck is made up of about 30 muscles that support and stabilise the head, neck and the upper part of the spine. These muscles are categorised into three main groups: anterior, lateral and posterior. The anterior neck muscles are a group of muscles covering the front area of the neck and can be further divided into five subgroups: superficial, scalene, suprahyoid, infrahyoid and anterior vertebral (prevertebral) muscles.
The superficial muscles are the most superficial in the anterior neck and include the platysma and sternocleidomastoid. The platysma is a sheet-like muscle that lies within the subcutaneous tissue of the anterior neck, superficial to the investing layer of deep cervical fascia. It originates from the skin and fascia overlying the clavicle region and passes superiorly along the neck. It lowers the mandible and tenses the skin of the lower neck and face. The sternocleidomastoid is a large, two-headed muscle of the neck. Its clavicular head originates from the medial third of the clavicle, while its sternal head arises from the manubrium of the sternum. The heads come together and ascend diagonally to insert onto the mastoid process of the temporal bone. The sternocleidomastoid muscle is innervated by the accessory nerve (CN XI) and anterior rami of spinal nerves C2 and C3. Its function depends on whether the muscle acts alone or together with its contralateral counterpart. Unilateral contraction produces lateral flexion of the neck on the same (ipsilateral) side and lateral rotation of the head to the opposite (contralateral) side. Bilateral contraction of the sternocleidomastoid muscles produce flexion of the neck, drawing the head towards the chest. When the head and neck are fixed, the sternocleidomastoid can also elevate the sternum and clavicle and thereby expand the thoracic cavity during forced inspiration.
The scalene group is comprised of three muscles known as the anterior, middle and posterior scalene muscles. The primary functions of this group are to flex the neck if contracting bilaterally, or laterally flex and contralaterally rotate the neck if contracting unilaterally. They can also elevate the first two ribs if the neck is fixed in place.
The suprahyoid and infrahyoid groups are named according to their position relative to the hyoid bone. The suprahyoid muscles are located superior to the hyoid bone and include the stylohyoid, mylohyoid, geniohyoid and digastric. They function primarily to elevate the hyoid bone or depress the mandible if the hyoid is fixed in place. The digastric muscle is a small muscle situated below the mandible, that extends from the mastoid process of the temporal bone to the chin. The muscle is composed of a posterior and an anterior belly, connected by an intermediate tendon, which represents their common insertion point. The infrahyoid muscles, conversely, are located inferior to the hyoid bone and include the sternohyoid, sternothyroid, thyrohyoid and omohyoid. They function primarily to depress the hyoid bone and larynx, and thereby open the laryngeal inlet and reestablish breathing after swallowing.
The anterior vertebral muscles, also known as the prevertebral muscles, are the deepest group, found immediately anterior to the cervical vertebrae and are surrounded by the prevertebral fascia of the neck. The muscles in this group are the rectus capitis anterior, rectus capitis lateralis, longus capitis and longus colli. They primarily function to flex the head and neck if contracting bilaterally or laterally flex and rotate the head and neck if contracting unilaterally.
Building Muscle: How Fast Can Your Body Change?
You may want to see also
Explore related products
Posterior neck muscles
The neck muscles support the head and help with various movements, such as chewing, swallowing, and breathing. There are about 30 neck muscles, which can be divided into three main categories: anterior (front), lateral (side), and posterior (back).
The posterior neck muscles are located on the posterior aspect of the neck and connect the skull to the vertebral column and pectoral girdle. They can be further subdivided into three groups: superficial, deep, and deepest.
The superficial layer is composed of the trapezius and the two splenius muscles (capitis and cervicis). The trapezius is responsible for producing lateral flexion and contralateral rotation of the head when contracting unilaterally, or extension of the head if contracting bilaterally. It also stabilizes and moves the scapula in different directions, depending on which fibres contract. The splenius muscles cause lateral flexion and ipsilateral rotation of the head and neck when contracting unilaterally, or extension of the head and neck when contracting bilaterally.
The deep layer is composed of the transversospinales muscles of the cervical region: semispinalis capitis, semispinalis cervicis, and multifidus cervicis. The primary function of this group is lateral flexion and contralateral rotation of the head and neck when contracting unilaterally, and extension of the head and neck when contracting bilaterally.
The deepest layer consists of the suboccipital muscles (rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior), interspinales cervicis, and intertransversarii colli. The primary function of the suboccipital muscles is to produce movements of the head (extension, lateral flexion, and rotation) and maintain posture. Due to their small size, the interspinales cervicis and the intertransversarii colli muscles are primarily proprioceptive and stabilizer muscles, although they also assist other muscles in the extension and lateral flexion of the neck, respectively.
Glutes: The Largest Muscle in the Human Body?
You may want to see also
Frequently asked questions
Yes, there are many muscles in the neck. These muscles are mainly responsible for the movement of the head in all directions.
The neck muscles can be divided into three main groups: anterior, lateral, and posterior neck muscles.
The anterior neck muscles help you move your mouth, your lower face, and the front of your neck. They also assist in swallowing and speaking.
The posterior neck muscles are grouped into three subgroups: superficial muscles, suboccipital muscles, and transversospinalis muscles.
