Deep Back And Suboccipital Triangle Flashcards
What are the 2 deep back muscles that are considered extrinsic?
Serratus posterior superior m.
Serratus posterior inferior m.
Origin/insertion/innervation/action:
Serratus posterior superior m.
Origin: lower part of ligamentum nuchae and cervical and thoracic spines
Insertion: ribs 2-5
Innervation: anterior/ventral rami of spinal nn. Of brachial plexus
Action: elevates ribs 2-5
Origin/insertion/innervation/action:
Serratus posterior inferior m.
Origin: thoracic and lumbar spines
Insertion: ribs 9-12
Innervation: anterior/ventral rami of spinal nn. of brachial plexus
Action: depresses ribs 9-12
What muscles of the deep back are considered intrinsic?
Splenius muscles
Erector spinae group
Transversospinalis group
Minor deep back muscles
What are the primary functions of extrinsic back muscles?
Move the limbs; thoracic proprioception
What are the primary functions of intrinsic back muscles?
Support upright posture; movements of vertebral column + proprioception
In general, what provides innervation to intrinsic back muscles?
Posterior/dorsal rami of spinal nn.
Origin of both splenius mm. (Splenius cervicis and Splenius capitis)
Nuchal ligament and spinous processes of T1-T6 vertebrae
Insertion of splenius capitis m.
Mastoid process and occipital bone of skull
Innervation of splenius capitis m.
Posterior (dorsal) rami of spinal nn. C3-4
Origin of splenius cervicis m.
Nuchal ligament and spinous processes of T3-6
Insertion of splenius cervicis m.
Transverse processes of C1-4
Innervation of splenius cervicis m.
Posterior (dorsal) rami of lower cervical spinal nn.
What are the unilateral vs. bilateral actions of the splenius muscles (capitis and cervicis)?
Unilateral: laterally flex neck and rotate head to ipsilateral side
Bilateral: extend head
What muscles are included in the erector spinae group?
Iliocostalis
Longissimus
Spinalis
What are the 3 parts to iliocostalis?
Iliocostalis lumborum, thoracis, and cervicis
What are the 3 parts to longissimus m.?
Longissimus thoracis, cervicis, and capitis
What are the 3 parts to spinalis m.?
Spinalis thoracis, cervicis, and capitis
What is the origin of all erector spinae muscles?
They have a common tendinous origin at the sacrum via erector spinae aponeurosis
Insertion of iliocostalis m.
Costal angle of ribs and cervical transverse processes
What provides innervation to ALL erector spinae mm?
Posterior rami of spinal nn.
Insertion of longissimus m.
Lower ribs, transverse processes of C2-T12, mastoid process of skull
Insertion of spinalis m.
Spinous processes of C2, T1-8, and occipital bone
What are the unilateral vs. bilateral actions of the erector spinae group?
Unilateral: laterally flex vertebral column
Bilateral: extend vertebral column and head
What muscles are included in the transversospinalis group?
Semispinalis m.
Multifidus m.
Rotatores m.
What muscle group is the deep layer occupying the trench between transverse and spinous processes?
Transversospinalis group
Origin of semispinalis m.
Transverse processes of C4-T10
Insertion of semispinalis m.
Spinous processes of C2-T4 and occipital bone
What innervates ALL muscles in transversospinalis group?
Posterior rami of spinal nn.
3 parts of semispinalis m.
Semispinalis thoracis, cervicis, and capitis
What muscle makes up the middle layer of short triangular bundles in the transversospinalis group and is the thickest in the lumbar region?
Multifidus m.
Origin of multifidus m.
Broad origin from sacrum, PSIS, common tendinous origin of erector spinae, mamillary processes of lumbar vertebrae, transverse processes of T1-3 and articular processes of C4-7
Insertion of multifidus m.
Spinous processes of vertebrae
Action of multifidus m.
Stabilizes vertebrae during location movements of vertebral column
What muscle is the deepest layer of rotator muscles in the transversospinalis group and is most developed in the thoracic region?
Rotatores m
Origin of rotatores m.
Vertebral transverse processes
Insertion of rotatores m.
Lamina and spinous processes of immediately superior vertebrae
Action of rotatores m.
Stabilizes vertebrae and assists with local extension and rotatory movements; possibly proprioception
What 3 muscles are included in the minor deep layer of the back?
Interspinalis m.
Intertransversarii m.
Levatores costarum m.
What muscle of the minor deep muscles of the back elevates the ribs, assists with respiration, and lateral flexion?
Levatores costarum m.
What muscle of the minor deep muscles of the back spans between adjacent SPINOUS processes?
Interspinalis m.
What muscle of the minor deep muscles of the back spans between adjacent transverse processes?
Intertransversarii m.
Action of interspinalis m.
Aids in extension/rotation in vertebral column
Action of intertransversarri m.
Aids in lateral flexion, bilateral stabilization of vertebral column