This muscle divides the neck into anterior and posterior triangles when viewed from the side Figure 6. Figure 6. Posterior and Lateral Views of the Neck.
The superficial and deep muscles of the neck are responsible for moving the head, cervical vertebrae, and scapulas. The posterior muscles of the neck are primarily concerned with head movements, like extension.
The back muscles stabilize and move the vertebral column, and are grouped according to the lengths and direction of the fascicles. The splenius muscles originate at the midline and run laterally and superiorly to their insertions. From the sides and the back of the neck, the splenius capitis inserts onto the head region, and the splenius cervicis extends onto the cervical region.
These muscles can extend the head, laterally flex it, and rotate it Figure 7. Figure 7. Muscles of the Neck and Back. The large, complex muscles of the neck and back move the head, shoulders, and vertebral column.
The erector spinae group forms the majority of the muscle mass of the back and it is the primary extensor of the vertebral column. It controls flexion, lateral flexion, and rotation of the vertebral column, and maintains the lumbar curve. The erector spinae comprises the iliocostalis laterally placed group, the longissimus intermediately placed group, and the spinalis medially placed group.
The iliocostalis group includes the iliocostalis cervicis , associated with the cervical region; the iliocostalis thoracis , associated with the thoracic region; and the iliocostalis lumborum , associated with the lumbar region. The three muscles of the longissimus group are the longissimus capitis , associated with the head region; the longissimus cervicis , associated with the cervical region; and the longissimus thoracis , associated with the thoracic region.
The third group, the spinalis group , comprises the spinalis capitis head region , the spinalis cervicis cervical region , and the spinalis thoracis thoracic region. The transversospinales muscles run from the transverse processes to the spinous processes of the vertebrae. Similar to the erector spinae muscles, the semispinalis muscles in this group are named for the areas of the body with which they are associated. The semispinalis muscles include the semispinalis capitis , the semispinalis cervicis , and the semispinalis thoracis.
The multifidus muscle of the lumbar region helps extend and laterally flex the vertebral column. Important in the stabilization of the vertebral column is the segmental muscle group , which includes the interspinales and intertransversarii muscles. These muscles bring together the spinous and transverse processes of each consecutive vertebra. Finally, the scalene muscles work together to flex, laterally flex, and rotate the head.
They also contribute to deep inhalation. The scalene muscles include the anterior scalene muscle anterior to the middle scalene , the middle scalene muscle the longest, intermediate between the anterior and posterior scalenes , and the posterior scalene muscle the smallest, posterior to the middle scalene.
Skip to main content. Module The Muscular System. Search for:. Axial Muscles of the Head, Neck, and Back Learning Objectives Identify the axial muscles of the face, head, and neck Identify the movement and function of the face, head, and neck muscles.
Figure 4. Muscles that Move the Tongue. Everyday Connections: Anesthesia and the Tongue Muscles Before surgery, a patient must be made ready for general anesthesia. Licenses and Attributions. CC licensed content, Shared previously. Lateral movement of cheeks e. Elevates hyoid and floor of mouth; depresses mandible. Central tendon attaches to clavicle and 1st rib. One belly attaches to hyoid; second to scapula. Together, flexes the neck; alone, one side bends head toward shoulder and turns face to opposite side.
Flexes vertebral column, depresses ribs and compresses abdomen. Compresses abdomen; depresses ribs; flexes, laterally flexes or rotates vertebral column. Inferior surfaces of ribs , costal cartilages , linea alba, and pubis.
Cartilages of inferior ribs, iliac crest, and lumbodorsal fascia. Xiphoid process, ribs and associated costal cartilages, and lumbar vertebrae. Contraction expands thoracic cavity, compresses abdominopelvic cavity. Together they depress ribs; one side alone produces lateral flexion of vertebral column. Tenses floor of pelvis, supports pelvic organs, flexes coccyx, elevates and retracts anus.
Depresses and protracts shoulder, rotates scapula downward, elevates ribs. Occipital bone, ligamentum nuchae, spinous processes of thoracic vertebrae. May elevate, retract, depress, or rotate scapula upward; elevate clavicle; extend neck. Flexion, adduction and medially rotation of arm. Spines of lower thoracic and all lumbar vertebrae, ribs , lumbodorsal fascia.
Extension, adduction and medially rotation of the arm. Abduction at shoulder, also extension, flexion, medial and lateral rotation. Extension, adduction and medial rotation at shoulder joint. Flexion at elbow and shoulder, supinates forearm. Flexion at proximal interphalangeal joint, metocarpophalangeal joint and wrist joint. Flexion at distal and proximal interphalangeal joints, metocarpophalangeal joint and wrist joint. Posterior surfaces of phalanges of finger Ilium, sacrum, coccyx and lumbodorsal fascia.
Extension and lateral rotation at the hip. Abduction and medial rotation at the hip. Flexion and medial rotation at hip; tenses fascia lata. Lateral rotation and abduction at thigh. Adduction, flexion, and medial rotation at hip. As above but also inferior portion produces extension and lateral rotation at hip.
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Table of Contents. The muscles of facial expression also known as the mimetic muscles can generally be divided into three main functional categories: orbital , nasal and oral. These striated muscles broadly originate from the surface of the skull and insert onto facial skin.
Their contraction uniquely pulls on facial skin in order to exhibit various facial expressions. As well as controlling the movement of the eyelids , these muscles also play a role in protecting the cornea from injury.
The occipitofrontalis muscle comprises of two main sections. These sections include the occipital located posteriorly and frontal located anteriorly bellies. The frontal belly is the major contributor to facial expression. This muscle comprises of three main sections. These sections include the orbital orbicularis , palpebral orbicularis and lacrimal orbicularis.
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