X. Myology of the Back Flashcards
What muscles are associated with the five muscle layers of the true back?
layer one consists of the trapezius and latissimus dorsi
layer two consists of the rhomboid major, rhomboid minor, and levator scapulae
layer three consists of the serratus posterior superior and serratus posterior inferior
layer four consists of the erector spinae
layer five consists of the transversospinalis
Which of the muscles attaching to spinous processes represent layer one of the true back?
trapezius, latissimus dorsi
Which of the muscles attaching to spinous processes represent layer two of the true back?
rhomboid major, rhomboid minor
Which muscles attaching to transverse processes represent layer two of the true back?
levator scapulae
Which of the muscles attaching to the scapula represent layer one of the true back?
trapezius
Which of the muscles attaching to the scapula represent layer two of the true back?
levator scapulae, rhomboid major, rhomboid minor
Which of the muscles attaching to the humerus represent layer one of the true back?
latissimus dorsi
Which muscles attaching to the lateral mass of C1 represent layer two of the true back?
levator scapulae
Which of the muscles in layer one of the true back acts to extend and laterally flex the head and neck and bilaterally acts to extend the neck?
trapezius
Which of the muscles in layer two of the true back acts to laterally flex and rotate the neck and bilaterally acts to extend the neck?
levator scapulae
Which of the muscles in layer one of the true back acts solely on the humerus?
latissimus dorsi
Which of the muscles in layer two of the true back acts solely on the scapula?
rhomboid major, rhomboid minor
Which of the muscles of the true back is innervated by the spinal accessory nerve?
trapezius
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
Which of the muscles of the true back is innervated by the thoracodorsal nerve?
latissimus dorsi
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
Which of the muscles of the true back are innervated by the dorsal scapular nerve?
levator scapulae, rhomboid major, rhomboid minor
What forms the dorsal scapular nerve?
the ventral ramus of C5
The levator scapulae is innervated by what nerves?
the dorsal scapular nerve (ventral ramus of C5) and branches from C3, C4, ventral rami
The rhomboid major is innervated by what nerves?
the dorsal scapular nerve (ventral ramus of C5) and branches from C4 ventral ramus
The rhomboid minor is innervated by what nerves?
the dorsal scapular nerve (ventral ramus of C5) and branches from C4 ventral ramus
What muscles lie just beneath the trapezius in the neck?
splenius capitis and splenius cervicis
What does the word “splenius” mean?
it is the Greek word for bandage
What part of the vertebra forms the osseous origin for the splenius muscles?
the spinous process
Splenius capitis will attach to what locations on the skull?
mastoid process of temporal bone, superior nuchal line of the occipital bone
Contraction of splenius capitis will result in what movements?
lateral flexion of head, rotation of face to the side; bilaterally they extend the head
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
Contraction of splenius cervicis will result in what movements?
lateral flexion and rotation of neck; bilaterally they extend the neck
What is the innervation of the splenius cervicis?
dorsal rami of lower cervical spinal nerves (C5-C7 cord levels)
Which muscles represent the fourth layer of the true back?
the erector spinae or sacrospinalis muscles
Which muscles are identified as erector spinae or sacrospinalis muscles?
iliocostalis, longissimus, spinalis
What muscles are classically identified as iliocostalis muscles?
iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis
What osseous parts of the vertebral column serve as an origin to the iliocostalis lumborum?
spinous processes of T11-T12, L1-L5, median sacral crest, lateral sacral crest
What is the insertion for the iliocostalis lumborum?
costal angles of the lower 6-9 ribs (rib 6 - rib 12 or rib 3 - rib 12)
Contraction of iliocostalis lumborum will result in what movements?
extension, lateral flexion and rotation of lumbar spine; lateral pelvic movement
What is the innervation of the iliocostalis lumborum?
dorsal rami of lower thoracic and all lumbar spinal nerves
What muscles are identified as subdivisions within the iliocostalis muscles?
iliocostalis lumborum pars lumborum and iliocostalis lumborum pars thoracis
What osseous parts of the vertebral column serve as an origin to the iliocostalis lumborum pars lumborum?
spinous processes of L1-L5
What is the insertion for the iliocostalis lumborum pars lumborum?
iliac crest of the innominate bone
What osseous parts of the vertebral column serve as an origin to the iliocostalis lumborum paras thoracis?
posterior superior iliac spine (PSIS) and iliac crest of the innominate bone
What is the insertion for the iliocostalis lumborum pars thoracis?
costal angles of the lower 8-9 ribs (rib 3 or 4 - rib 12)
Which subdivision of the iliocostalis muscle appears to have a reversal of origin - insertion?
iliocostalis lumborum pars lumborum
What osseous parts of the vertebral column serve as an origin to the iliocostalis thoracis?
none
What is the origin for the iliocostalis thoracis?
costal angles of the lower 6-7 ribs (rib 5 or 6 - rib 12)
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 serves as an insertion for the iliocostalis thoracis?
transverse process of C7
Which subdivision of the iliocostalis primarily originates and inserts on ribs?
iliocostalis thoracis
Contraction of iliocostalis thoracis will result in what movements?
extension, lateral flexion of the thoracic spine
What is the innervation of the iliocostalis thoracis?
dorsal rami of upper 6 thoracic spinal nerves (T1-T6 cord levels)
What osseous parts of the vertebral column serve as an origin to the iliocostalis cervicis?
none
What is the origin for the iliocostalis cervicis?
costal angles of the upper 3-6 ribs (ribs 1-3 or ribs 1-6)
What is the insertion for the iliocostalis cervicis?
posterior tubercle of transverse process of C(3) C4-C6
Contraction of iliocostalis cervicis will result in what movements?
extension, lateral flexion and rotation of the lower cervical spine
What is the innervation of the iliocostalis cervicis?
dorsal rami of T1, T2 spinal nerves, sometimes C8 spinal nerve (C8, T1, T2 cord levels)
What muscles are classically identified as longissimus muscles?
longissimus thoracis, longissimus cervicis, and longissimus capitis
What osseous parts of the vertebral column serve as an origin to the longissimus thoracis?
accessory process and transverse processes of L1-L5, spinous processes of L3-L5 and median sacral crest S1-S3
What non-vertebral column site serves as an origin to the longissimus thoracis?
posterior superior iliac spine (PSIS) of the innominate bone
What is the insertion for the longissimus thoracis?
transverse tubercle of all thoracic segments
between tubercle and costal angle of the lower 9-10 ribs (rib 2 or 3 - rib 12)
Which erector spinae muscle is attached to the accessory process?
longissimus thoracis
Contraction of longissimus thoracis will result in what movements of the vertebral column?
lateral flexion of the thoracic spine (lumbar spine inadvertently)
bilaterally acts to extend the thoracic and lumbar spine, holds thoracic and lumbar spine erect
increases the lumbar lordotic curve
lateral pelvic movement
What is the innervation of the longissimus thoracis?
dorsal rami of all thoracic and lumbar spinal nerves (cord levels T1-T12, L1-L5)
What muscles are identified as subdivisions within the longissimus thoracis muscles?
longissimus thoracis pars lumborum and longissimus thoracis pars thoracis
What osseous parts of the vertebral column serve as an origin to the longissimus thoracis pars lumborum?
accessory process and medial part of transverse process of L1-L5
What is the insertion for the longissimus thoracis pars lumborum?
posterior superior iliac spine (PSIS) of the innominate bone
Contraction of longissimus thoracis pars lumborum will result in what movements?
lateral flexion of lumbar spine
bilaterally extend lumbar spine and increase lumbar lordotic curve
What osseous parts of the vertebral column site serve as an origin to the longissimus thoracis pars thoracis?
spinous processes of L3-L5 and median sacral crest S1-S3
What non-vertebral column site serves as an origin to the longissimus thoracis pars thoracis?
posterior superior iliac spine (PSIS) of the innominate bone
What is the insertion for the longissimus thoracis pars thoracis?
transverse process of all thoracis
between tubercle and costal angle of all ribs (rib 1 - rib 12)
Contraction of longissimus thoracis pars thoracis will result in what movements?
lateral flexion of thoracic spine (lumbar spine inadvertently)
bilaterally extend thoracic spine (lumbar spine inadvertently)
Which subdivision of the longissimus muscle appears to have a reversal of origin - insertion?
longissimus thoracis pars lumborum
What osseous parts of the vertebral column serve as an origin to the longissimus cervicis?
transverse tubercles of T1-T5 or T6
What osseous parts of the vertebral column serve as an insertion for the longissimus cervicis?
posterior tubercle of transverse processes from C2-C6 or C7
articular processes from C2-C6 or C7
Contraction of longissimus cervicis will result in what movements?
lateral flexion of the neck, bilaterally act to extend neck
What is the innervation of the longissimus cervicis?
dorsal rami of C4-C8 and T1-T12 spinal nerves (C4-C8 and T1-T12 cord levels)
What osseous parts of the vertebral column serve as an origin to the longissimus capitis?
transverse tubercle of T1-T5 and articular processes of C4-C7
What is the insertion for the longissimus capitis?
mastoid process of temporal bone
Contraction of longissimus capitis will result in what movements?
lateral flexion and rotation of the head, bilaterally act to extend head
What is the innervation of the longissimus capitis?
dorsal rami of C1-C3 or C4 spinal nerves, (C1-C3 or C4 cord levels)
Which erector spinae muscles attach to cervical articular processes?
longissimus cervicis and longissimus capitis
What muscles are classically identified as spinalis muscles?
spinalis thoracis, spinalis cervicis, and spinalis capitis
What osseous parts of the vertebral column serve as an origin to the spinalis thoracis?
spinous processes of T11 and T12 -L1 and L2
What is the insertion for the spinalis thoracis?
spinous process of T1-T4 or as low as T8
Contraction of spinalis thoracis will result in what movements of the vertebral column?
extension of the thoracic spine
What is the innervation of the spinalis thoracis?
dorsal rami of all thoracic and upper lumbar spinal nerves
What osseous parts of the vertebral column serve as an origin to the spinalis cervicis?
spinous process of C7 and T1-T6
What osseous parts of the vertebral column serve as an insertion for the spinalis cervicis?
spinous process from C2-C4
Contraction of spinalis cervicis will result in what movements?
lateral flexion and rotation of the cervical spine, bilaterally act to extend the neck
What is the innervation of the spinalis cervicis?
dorsal rami of all cervical spinal nerves (C1-C8 cord levels)
What osseous parts of the vertebral column serve as an origin to the spinalis capitis?
spinous process of C7 and T1-T6 or T7
What is the insertion for the spinalis capitis?
below the superior nuchal line of the occipital bone
Contraction of spinalis capitis will result in what movements?
lateral flexion and rotation of the head, bilaterally act to extend head
What is the innervation of the spinalis capitis?
dorsal rami of lower cervical and upper thoracic spinal nerves
Which muscles are identified as transversospinalis muscles?
semispinalis, multifidus, and rotators
Transversospinalis muscles represent what layer of the true back?
layer five
Based on the name of this group, what is the origin - insertion of the transversospinalis?
transverse process origin, spinous process insertion
How many vertebrae can be attached to a single segment by transversospinalis muscles?
as many as nine vertebrae
What muscles are classically identified as semispinalis muscles?
semispinalis thoracis, semispinalis cervicis, and semispinalis capitis
What osseous parts of the vertebral column serve as an origin to the semispinalis thoracis?
transverse tubercles of T6-T10 or as low as T12
What segment will represent the lowest attachement site for the semispinalis thoracis?
T12
What is the insertion for the semispinalis thoracis?
spinous processes of C6-C7 and T1-T4
Contraction of semispinalis thoracis will result in what movements?
extension, lateral flexion and rotation of upper thoracic and lower cervical spine, bilaterally they act to extend the thoracic spine
What is the innervation of the semispinalis thoracis?
dorsal rami of T1-T6 spinal nerves (cord levels T1-T6)
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