Deep Back Muscles Flashcards
What are the muscles that make up the deep back?
Splenious capitus, splenious cervicis, erector spinae (3 muscles), transversospinalis (3 muscles), and suboccipital.
What innervates the deep back muscles?
Dorsal rami of spinal nerves.
What is the origin of the splenious capitis?
Lower half of the liamentum nuchae, spinous processes C7-T4.
What is the insertion of the splenious capitis?
Mastoid process of the skull and below the lateral 1/3 of the superior nuchal line.
What are the actions of the splenious capitis?
Bilateral contraction - extension of the neck
Unilateral contraction - Draw and rotate the head to one side
What innervates the splenious capitis?
Segmentally by the dorsal rami of cervical nerves.
What is the origin of the splenious cervicis?
Spinous processes T3-T6.
What is the insertion of the splenious cervicis?
Transverse processes C1-C3.
What are the actions of the splenious cervicis?
Bilateral contraction - extension of the neck.
Unilateral contraction - draw and rotate the head to one side.
What innervates the splenious cervicis?
Segmentally by the dorsal rami of the cervical nerves.
What 3 muscles make up the erector spinae?
Iliocostalis, Longissimus, and Spinalis.
What is the origin of the iliocostalis?
Ilium and ribs.
What is the origin of the longissimus?
Transverse processes.
What is the origin of the spinalis?
Spinous processes.
What is the insertion of the iliocostalis?
Ribs and Transverse processes.
What is the insertion of the longissimus?
Transverse processes.
What is the insertion of the spinalis?
Spinous processes.
What are the actions of the erector spinae?
Bilateral contraction - extension of the vertebral column and controls posture.
Unilateral contraction - Lateral flexion of vertebral column.
What innervates the erector spinae muscles?
Segmentally by the dorsal rami of the spinal nerves.
What 3 muscles make up the transversospinalis?
Semispinalis, Multifidus, and Rotatores.
What is the origin of the transversospinalis muscles?
All originate from transverse processes of vertebrae.
What is the insertion of the transversospinalis muscles?
All insert upon the spines of vertebrae, superior to origin. Each muscle spans a different length of vertebrae.
What are the actions of the transversospinalis muscles?
Bilateral contraction - extension of the vertebral column
Unilateral contraction - Rotation of the vertebral column to contralateral side of the contracting muscle or muscle group.
What innervates the transversospinalis muscles?
Segmentally by dorsal rami of the thoracolumbar spinal nerve.
What 4 muscles make up the suboccipital?
Rectus Capitis Posterior Major and Minor, and Obliquus Capitis Superior and Inferior.
What is the origin of the Rectus Capitis Posterior Major?
Spinous process of the axis vertebrae (C2).
What is the origin of the Rectus Capitis Posterior Minor?
Posterior tubercle of the atlas vertebrae (C1).
What is the origin of the Obliquus Capitis Superior?
Transverse process of axis vertebrae (C2).
What is the origin of the Obliquus Capitis Inferior?
Spinous process of axis vertebrae (C2).
What is the insertion of the Rectus Capitis Posterior Major?
Lateral part of the inferior nuchal line of the occipital bone.
What is the insertion of the Rectus Capitis Posterior Minor?
Medial part of the inferior nuchal line of the occipital bone.
What is the insertion of the Obliquus Capitis Superior?
Occipital bone. (Lateral half inferior nuchal line)
What is the insertion of the Obliquus Capitis Inferior?
Transverse process atlas vertebrae (C1).
What are the actions of the Rectus Capitis Posterior Major?
Extension of the head, and ipsilateral rotation of the head.
What are the actions of the Rectus Capitis Posterior Minor?
Extension of the head.
What are the actions of the Obliquus Capitis Superior?
Extension of the head, and bends ipsilaterally.
What are the actions of the Obliquus Capitis Inferior?
Ipsilateral rotation of the face.
What innervates the suboccipital muscles?
Suboccipital nerve (posterior rami of C1).
What muscles make up the suboccipital triangle?
Medial - Rectus Capitis Posterior Major
Lateral - Obliquus Capitis Superior
Inferior - Obliquus Capitis Inferior.
What are some of the contents of the suboccipital triangle?
Vertebral artery, suboccipital nerve, suboccipital venous plexus.
