Musculature of the Back and Neck Flashcards
what are the 2 major groups of back muscles
extrinsic and intrinsic
explain extrinsic muscles
superficial and intermediate muscles that produce and control limb and respiratory movements
explain intrinsic muscles
muscles that specifically act on the vertebral column
produces movements and maintain posture
extrinsic muscles that connect the upper limbs to the trunk
traps
latissimus dorsi
levator scapulae
rhomboid major and minor
intermediate (extrinsic) muscles
serratus posterior superior
serratus posterior inferior
serratus posterior posterior
origin: ligamentum nuche, spinous proccesses C7-T3
insertion: superior borders ribs 2-4
innervation: 2nd-5th intercostal nerves
action: elevate ribs
serratus posterior inferior
origin: spinous processes T11-L2
insertion: inferior borders ribs 8-12
innervation: ventral rami T9-T12 spinal nerves
action: depresses ribs
what is the nerve rule of the deep (intrinsic) muscles
all innervated by the dorsal rami of the spinal nerves
what are the layers of the deep (intrinsic) muscles
superficial
intermediate
deep
minor deep
what are the muscles in the superficial deep layer
splenius capitis
splenius cervicis
splenius capitis
innervation: dorsal rami of the spinal nerves
action: unilateral –> flexes and rotates head to the same side
bilateral–> extends cervical spine and head
splenius cervicis
innervation: dorsal rami of the spinal nerves
action: unilateral –> flexes and rotates head to the same side
bilateral –> extends cervical spine and head
muscles of the intermediate (deep) muscles
errector spinae (3 parts)
-iliocostalis
-longissimus
-spinalis
all rotate to the same side
iliocostalis
innervation: dorsal rami of the spinal nerves
action: unilateral –> bends spine laterally to the same side
bilateral–> extends the spine
longissimus
innervation: dorsal rami of the spinal nerve
action: unilateral –> head rotation and neck flexion to same side
bilateral –> head and vertebral column extension
spinalis
innervation: dorsal rami of the spinal nerves
action: unilateral –> bends cervical and thoracic spine to same side
bilateral –> extends cervical and thoracic spine
what are the muscles in the deep layer of the intrinsic muscles
transverospinalis (3 parts)
-semispinalis
-multifidus
-rotatores
semispinalis
innervation: dorsal rami of the spinal nerves
action: posterior stabilizer
unilateral -> bends head, cervical and thoracic spine to the same side
-rotates head to the opposite side
bilateral –> extends spine
multifidus
innervation: dorsal rami of the spinal nerves
action: posterior stabilizer
unilateral: flexes spine to same side
-rotates to opposite side
bilateral –> extends spine
rotatores
innervation: dorsal rami of the spinal nerves
action: posture stabilizer
unilateral –> rotates spine to opposite side
bilateral–> extends the thoracic spine
what are the muscles in the minor deep layer of the intrinsic muscles
interspinales
intertransversarii
levator costarum
interspinales
innervation: dorsal rami of the spinal nerves
action: side in vertebral column extension, rotation to the same side
intertransversarii
innervation: dorsal and ventral rami of spinal nerves
action: unilateral –> bends the cervical and same side lumbar spines laterally and to the same side
bilateral –> stabilizes and extends the cervical and lumbar spines
levatores costarum
innervation: dorsal rami of C8-T11 spinal nerves
action: unilateral –> bend thoracic spine to same side, rotates to opposire side
bilateral –> extends thoracic spine
what are the suboccipital muscles
rectus capitis posterior major
rectus capitis posterior minor
obliquus capitis superior
obliquus capitis inferior
each muscle is a pair, so there are 8 total muscles
rectus capitis posterior major
origin: spinous processes of C2
insertion: lateral part of inferior nuchal line of occipital bone
innervation: dorsal ramus of C1 spinal nerve (occipital nerve)
action: unilateral–> head ipsilateral rotation
bilateral –> head extension
rectus capitus posterior minor
origin: posterior tubercle C1
insertion: medial part of inferior nuchal line of occipital bone
innervation: sub occipital nerve
action: unilateral–> head ipsilateral rotation
bilateral –> head extension
obliquus capitis superior
origin: transverse process C1
insertion: occipital bone (inferior nuchal line, middle third and above rectus capitis posterior major)
innervation: sub occipital nerve
action: unilateral –> tilts head to the same side and rotates the head to the opposite side
bilateral –> head extension
obliquus capitis inferior
origin: spinous process C2
insertion: transverse process C1
innervation: sub occipital nerve
action: unilateral –> neck ipsilateral rotation
bilateral –> head extension
