Myology of the Back Flashcards
The trapezius is innervated by what nerve?
the spinal accessory nerve
What forms the spinal accessory nerve innervating the trapezius?
C1-C5 cord levels contribute to the spinal root of the spinal accessory nerve
The latissimus dorsi is innervated by what nerve?
the thoracodorsal nerve
What forms the thoracodorsal nerve innervating the latissimus dorsi?
ventral rami from C6-C8
What forms the dorsal scapular nerve?
the ventral ramus of C5
What is the innervation of the splenius capitis?
dorsal rami of middle cervical spinal nerves (C3-C5 cord levels)
Splenius cervicis will attach to what locations on the spine?
lateral mass of C1 and posterior tubercle of transverse process on C1-C4
Which muscles are identified as erector spinae or sacrospinalis muscles?
iliocostalis, longissimus, spinalis
What is the innervation of the iliocostalis lumborum?
dorsal rami of lower thoracic and all lumbar spinal nerves
What osseous parts of the vertebral column serve as an origin to the iliocostalis thoracis?
none
What is the insertion for the iliocostalis thoracis?
costal angles of the upper 6-7 ribs, transverse process of C7
What osseous parts of the vertebral column serve as an origin to the longissimus thoracis?
accessory process and transverse process of L1-L5, spinous processes of L3-L5 and median sacral crest S1-S3
What is the innervation of longissimus cervicis?
dorsal rami C4-C8 and T1-T2 spinal nerves
What osseous parts of the vertebral column serve as an origin to the spinalis thoracis?
spinous processes of T11 and T12-L1 and L2
Which muscles are identified as transversospinalis muscles?
semispinalis, multifidis, and rotators
How many vertebrae can be attached to a single segment by transversospinalis muscles?
as many as nine vertebrae
What segment will represent the lowest attachment site for the semispinalis thoracis?
T12
What osseous parts of the vertebral column serve as an origin to the semispinalis cervicis?
transverse tubercles of T1-T5 or T6 and articular processes of C4-C7
What osseous parts of the vertebral column serve as an origin to the semispinalis capitis?
transverse tubercles of C7, T1-T6 or T7 and articular processes of C4-C6
The semispinalis capitis and spinalis capitis may fuse to form what muscle?
biventer cervicis
What osseous parts of the vertebral column serve as an origin to the classic multifidis?
articular process of C4-C7, transverse processes of T1-T12, mammillary processes of L1-L5 and the dorsal surface of S1-S4 or S5
Contraction of the classic multifidis will result in what movements of the vertebral column?
lateral flexion and rotation of the spine, maintains the lumbar lordotic curve and prevents entrapment of zygapophyseal capsular ligament during movement
Contraction of multifidis cervicis will result in what movements?
alters the zygapophyseal capsular ligament response to load distribution determines the cervical spine response to injury as evidenced by neck pain and is a significant contributor to postural control of the head and neck
Contraction of multifidis lumborum will result in what movements?
lateral flexion and rotation of the lumbar spine, maintains the lumbar lordotic curve and prevents entrapment of lumbar zygapophyseal capsular ligament during movement
Which muscles of the spine exhibit a reversal of the expected origin- insertion combination?
iliocostalis lumborum pars lumborum, longissimus thoracic pars lumborum and multifidis lumborum
Rotator muscles are typically identified in what region of the spine?
the thoracic region
Which suboccipital muscle lacks an attachment to the skull?
obliquus capitis inferior
Which nerve will innervate all suboccipital muscles?
dorsal ramus of C1, the suboccipital nerve
What is the origin of the obliquus capitis inferior?
C2 spinous process and lamina
An increase in the density of muscle spindles is most apparent in which suboccipital muscle?
obliquus capitis inferior
What is the proposed function of the suboccipital muscle group?
postural stabilizers of the atlanto-occipital and atlanto-axial joints
Which suboccipital muscles are known to attach to dura mater?
rectus capitis posterior major, rectus capitis posterior minor and obliquus capitis inferior
Interspinalis is paired in which regions of the spine?
cervical and lumbar regions
Based on the density of muscle spindles what is the proposed function of the interspinalis?
acts as a proprioceptive transducer in conjunction with intertransversarii to coordinate the smooth movement of the spine and to maintain appropriate posture
Which is the cervical intertransversarii is innervated by dorsal rami of cervical spinal nerves?
posterior medial belly, cervical intertransversarii
What is the origin of the medial belly of the lumbar intertransversarii?
accessory process of transverse process L1-L4 and mammillary process of superior articular process L1-L4
Which muscle group in innervated by both dorsal rami and ventral rami of spinal nerves?
intertransversarii
Based on the density of muscle spindles what is the proposed function of the intertransversarii?
acts as a proprioceptive transducer in conjunction with interspinalis to coordinate the smooth movement of the spine and to maintain appropriate posture
What is the origin of longus colli?
vertebral bodies of C5-C6, T1-T3 and anterior tubercles of transverse processes C3-C5
What is the origin of the rectus capitis anterior?
lateral mass and costal element of the transverse process of C1
What will innervate the rectus capitis anterior?
ventral rami of C1-C2 spinal nerves
What will innervate the rectus capitis lateralis?
ventral rami of C1-C2 spinal nerves
What is the insertion of the anterior scalene?
ridge and anterior scalene tubercle of the first rib
What is the insertion of the middle scalene?
between the tubercle and groove for the subclavian artery on the first rib
What is the insertion of the posterior scalene
outer surface of second rib
What will innervate the posterior scalene?
the ventral rami of C6-C8 spinal nerve
The quadratus lumborum is implicated in the formation of which ligament?
the iliolumbar ligament
What is the origin of the psoas major?
vertebral bodies T12, L1-L5, S1 and transverse processes of L1-L5
What is the origin of psoas minor?
vertebral bodies T12, L1
What will innervate the psoas minor?
the ventral ramus of L1 spinal nerve
