Posterior Spine Muscles Flashcards
What are the superficial muscles of the back
the trapezius, the latissimus dorsi, levator scapulae, Rhomboid major, rhomboid minor
Intermediate muscles of the back
serrates posterior superior and serrates posteror inferior
deep muscles of the back
- Superficial layer (splenius capitis, splenius carvicis)
- intermediate layer (erector spinae: iliocostalis, longissimus, spinalis)
- Deep layer (intrinsic muscles: semispinalis, multifidus, rotatores)
Trapezius
O: external occipital protuberance, ligamentum niche, spinous processes of C7-T12
I: posterior border of lateral third of clavicle, acromion process and spine of scapula.
N: spinal root of the accessory nerve CN XI
A: elevation from the upper fibers, retraction from the middl fibers and depression from the lower fibers
Latissimus Dorsi
O: spinous process of the vertebrate T7-L5, thoracolumbar fascia, iliac crest, inferior 3 to 4 ribs and inferior angle of the scapula.
I: medial lip of inter-tubercular groove of the humerus (anterior to terms major)
N: thoracodorsal nerve
A: extends, adducts and medially rotates the humerus, elevates the body when climbing
Levator Scapulae
O: posterior tubercles of transverse processes of C1 to C4 vertebrate
I: superior part of the medial border of the scapula
N: dorsal scapular nerve (C4-5)
A: elevates scapula, rotates head to the same side
Rhomboid major
O:spinous process of T2-T5 vertebrate
I: medial border of the scapula from the level of the spine to the inferior angle
N: dorsal scapular nerve (C4-5)
A: retracts and downwardly rotates the scapula
Rhomboid minor
O: spinous process of C7 and T1 and the ligamentum nuchae
I: medial border of the scapula from the level of the spine to the superior angle
N: dorsal scapular nerve (C4-5)
A: retracts and downwardly rotates the scapula
Serratus posterior superior
O: ligamentum nuchae, spinous process C7-T3
I: 2nd to 5th ribs
N: ventral primary rami of first 3-4 thoracic nerves
A: elevates the superior 4 ribs to increase the size of the thorax
Serratus posterior inferior
O: spinous process of T11 thru L2
I: the inferior three or four ribs
N: ventral primary rami of the last four thoracic nerves
A: depress the inferior 3-4 ribs to prevent superior pull by the diaphragm
Splenius capitis
O: ligamentum nuchae and spinous process of C7-T3
I: mastoid process, occipital bone
N: dorsal primary rami
A: rotate the head and neck to the same side, head and neck extension
Splenius cervicis
O: spinous process of T3-T6
I: transverse process of C1-C4
N: dorsal primary rami
A: rotate the head and neck to the same side, extend neck and head
What are the three vertical columns of the erector spinae muscles
iliocostalis, longissimus and spinalis.
What is the common origin of the erector spinae muscles
broad tendon that attaches to the iliac crest, sacrum, sacroiliac ligaments, and sacral and inferior lumbar spinous process
What was the innervation of the erector spinae muscles
dorsal primary rami
what are the three parts of the iliocostalis
the lumborum, thoracis, cervicis
Lumborum
part of the iliocostalis. from the iliac crest and attaches into the angle of the inferior six ribs
Thoracis
arises from the six lower ribs and attaches to the six upper ribs
Cervicis
arises from the six upper ribs and attaches to the transverse processes of the lower cervical vertebrate 4-6
Deep layer of intrinsic muscles
semispinalis, multifidus, rotatores
Semispinalis
Developed in cervical region. bilaterally extends the head, and unilaterally rotates the head to the same side. span 5-6 segments, innervated by the dorsal rami of c-spine nerves
Multifidus
muscles from C2-S4. Most prominent in lumbar region. originate on the vertebral arches. unilaterally, flexes the trunk laterally, rotates vertebrate to the opposite side. Bilaterally extends the trunk.
Rotatores
found along the whole length of the vertebral column. easies to see in T-spine. from the transverse processes and then attach on the spinous process of the superior vertebrate. Rotate the superior vertebrate to the opposite side. Dorsal rami of spinal nerves
