Muscles of the Neck: Anatomy

Overview

Anterior muscles of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess

Superficial layer:

• Platysma: depresses the mandible Mandible The largest and strongest bone of the face constituting the lower jaw. It supports the lower teeth. Jaw and Temporomandibular Joint: Anatomy and tenses the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess
• Sternocleidomastoid (SCM): flexion Flexion Examination of the Upper Limbs, extension Extension Examination of the Upper Limbs, and rotation Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. X-rays of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess
• Subclavius: anchors the clavicle Clavicle A bone on the ventral side of the shoulder girdle, which in humans is commonly called the collar bone. Clavicle Fracture

Scalenes: lateral and anterior flexion Flexion Examination of the Upper Limbs of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess:

• Anterior scalene
• Medial scalene
• Posterior scalene

Suprahyoids: elevate the hyoid bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types during swallowing Swallowing The act of taking solids and liquids into the gastrointestinal tract through the mouth and throat. Gastrointestinal Motility:

• Digastric 
• Mylohyoid
• Geniohyoid
• Stylohyoid

Infrahyoids: depress the hyoid bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types and facilitate downward movement of the larynx Larynx The larynx, also commonly called the voice box, is a cylindrical space located in the neck at the level of the C3-C6 vertebrae. The major structures forming the framework of the larynx are the thyroid cartilage, cricoid cartilage, and epiglottis. The larynx serves to produce sound (phonation), conducts air to the trachea, and prevents large molecules from reaching the lungs. Larynx: Anatomy after swallowing Swallowing The act of taking solids and liquids into the gastrointestinal tract through the mouth and throat. Gastrointestinal Motility:

• Sternohyoid
• Thyrohyoid
• Omohyoid
• Sternothyroid

Lateral (prevertebral) muscles of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess

The function includes anterior and lateral flexion Flexion Examination of the Upper Limbs of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess and stabilization of the cervical vertebral column Vertebral column The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy:

• Longus capitis
• Longus colli
• Rectus capitis anterior
• Rectus capitis lateralis

Posterior muscles of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess

Splenius group: bilateral contraction ( extension Extension Examination of the Upper Limbs of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess) and unilateral contraction (lateral flexion Flexion Examination of the Upper Limbs and ipsilateral rotation Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. X-rays):

• Splenius capitis
• Splenius cervicis

Suboccipitals (postural muscles): aid in extension Extension Examination of the Upper Limbs, lateral flexion Flexion Examination of the Upper Limbs, and rotation Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. X-rays of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess:

• Rectus capitis posterior major
• Rectus capitis posterior minor
• Obliquus capitis inferior
• Obliquus capitis superior

Transversospinalis group: rotation Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. X-rays and extension Extension Examination of the Upper Limbs of the vertebral column Vertebral column The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy:

• Semispinalis capitis
• Semispinalis cervicis
• Rotatores cervicis
• Interspinales cervicis
• Intertransversarii

Anterior Neck Muscles

Superficial layer

Scalenes

Suprahyoids

Infrahyoids

Lateral (Prevertebral) Neck Muscles

Posterior Neck Muscles

Splenius group

Suboccipitals

Transversospinalis group

Clinical Relevance

• Torticollis Torticollis A symptom, not a disease, of a twisted neck. In most instances, the head is tipped toward one side and the chin rotated toward the other. The involuntary muscle contractions in the neck region of patients with torticollis can be due to congenital defects, trauma, inflammation, tumors, and neurological or other factors. Cranial Nerve Palsies (also known as wry neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess): an abnormal, asymmetrical head or neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess position due to trauma, muscle tone Muscle tone The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. Skeletal Muscle Contraction disorders, congenital muscle tightness, or extrinsic masses. Torticollis Torticollis A symptom, not a disease, of a twisted neck. In most instances, the head is tipped toward one side and the chin rotated toward the other. The involuntary muscle contractions in the neck region of patients with torticollis can be due to congenital defects, trauma, inflammation, tumors, and neurological or other factors. Cranial Nerve Palsies is characterized by abnormal tone or length of the cervical muscles. Even without treatment, the pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways usually goes away after a few days. Torticollis Torticollis A symptom, not a disease, of a twisted neck. In most instances, the head is tipped toward one side and the chin rotated toward the other. The involuntary muscle contractions in the neck region of patients with torticollis can be due to congenital defects, trauma, inflammation, tumors, and neurological or other factors. Cranial Nerve Palsies is predominantly a clinical diagnosis and management includes physical therapy Physical Therapy Becker Muscular Dystrophy and dystonia Dystonia Dystonia is a hyperkinetic movement disorder characterized by the involuntary contraction of muscles, resulting in abnormal postures or twisting and repetitive movements. Dystonia can present in various ways as may affect many different skeletal muscle groups. Dystonia medication.
• Triangles of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess: The neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess is quadrangular. The boundaries of the quadrangular shape include the mandible Mandible The largest and strongest bone of the face constituting the lower jaw. It supports the lower teeth. Jaw and Temporomandibular Joint: Anatomy, the upper border of the clavicle Clavicle A bone on the ventral side of the shoulder girdle, which in humans is commonly called the collar bone. Clavicle Fracture, the midline, and the anterior margin of the trapezius. The quadrangular shape is divided into an anterior and posterior triangle Posterior triangle Triangles of the Neck: Anatomy by the SCM muscle. The anterior triangle Anterior Triangle Triangles of the Neck: Anatomy is further subdivided into the muscular (omotracheal) triangle, the carotid triangle Carotid triangle Triangles of the Neck: Anatomy, the submandibular triangle Submandibular triangle Triangles of the Neck: Anatomy, and the submental triangle Submental triangle Triangles of the Neck: Anatomy. The posterior triangle Posterior triangle Triangles of the Neck: Anatomy is further subdivided into the occipital triangle Occipital triangle Triangles of the Neck: Anatomy and the supraclavicular (omoclavicular) triangle. The triangles are again subdivided into the anterior and posterior triangles, and then further divided. The triangles serve as anatomic landmarks for many important structures (e.g., the carotid sheath and the spinal accessory nerve Spinal accessory nerve The 11th cranial nerve which originates from neurons in the medulla and in the cervical spinal cord. It has a cranial root, which joins the vagus nerve (10th cranial) and sends motor fibers to the muscles of the larynx, and a spinal root, which sends motor fibers to the trapezius and the sternocleidomastoid muscles. The 12 Cranial Nerves: Overview and Functions).