Muscles of the Back Flashcards
list the superficial muscles of back (intermediate included)
7
trapezius, latissimus doors, levator scapulae, rhomboid major, rhomboid minor (serratus posterior superior and inferior)
muscles of the back that move the limbs and are innervated by the CN1 or branches of the brachial plexus
extrinsic muscles
are extrinsic or intrinsic back muscles hypaxial?
extrinsic
epaxial are intrinsic
intrinsic muscles
support upright posture and allow movements of vertebral column
involved in proprioception, innervated by dorsal rami of spinal nerves
posterior appendicular muscles
posterior muscles that attach the scapula and humerus to axial skeleton or scapula to humerus
includes the superficial and intermediate muscles of back
Proximal attachment of trapezius
origin
external occipital protuberance of skull, nuchal ligament, spinous process of C7-T12 vertebrae
Distal attachment of trapezius (insertion)
lateral third of clavicle (anterior), acromion, spine of scapula (posterior)
actions of trapezius (3)
- elevation and upward rotation of scapula – rotates glenoid fossa superiorly
- retracts scapula
- depression and upward rotation of scapula
innervation of trapezius
motor: accessory nerve
sensory: ventral rami of C3 and C4
proximal attachment of Latissimus dorsi
spinous process of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, inferior 3 ribs
distal attachment of Latissimus dorsi
floor of inter tubercular sulcus of humerus
actions of Latissimus dorsi
extends, adducts, and medially rotates humerus
raises torso towards arms during climbing
innervation of Latissimus dorsi
throacodorsal nerves
main action of the Latissimus dorsi
moves the humerus at the shoulder (glenohumeral) joint
main action of the trapezius
moves the scapula
proximal attachment of rhomboid major
spinous processes of T2-T5
distal attachment of rhomboid major
medial border scapula from level of spine to inferior
actions of rhomboids
retract, elevate, rotate scapula downward (fix it to thoracic wall)
innervations of the rhomboids
dorsal scapular nerve
proximal attachment of rhomboid minor
nuchal ligament, spinous process of C7 and T1
distal attachment of rhomboid minor
medial end of scapular spine
proximal attachment of Levator scapulae
posterior tubercle of transverse process of first 4 cervical vertebrae
distal attachment of Levator scapulae
medial border of scapula
superior part of scapular spine
actions of Levator scapulae
elevates scapula and tilts glenoid fossa inferiorly by rotating scapula
innervation of Levator scapulae
dorsal scapular nerve and ventral rami of cervical spinal nerves
proximal attachment of serratus posterior superior
nuchal ligament, spinous processes of C7-T3 vertebrae
distal attachment of serratus posterior superior
superior border of ribs 2-4
actions of serratus posterior superior
elevates ribs
innervation of serratus posterior superior
ventral rami of T2-5 intercostal nerves
proximal attachment of serratus posterior inferior
spinous process of T11-L2 vertebrae
distal attachment of serratus posterior inferior
inferior borders of rides 8-12, near angles
innervation of serratus posterior inferior
ventral rami of intercostal and subcostal nerves
are dorsal branches epaxial or hypaxial?
epaxial
major groups of epaxial/intrinsic/deep back muscles
splenius, erector spinae, and transversospinalis
2 muscles of the splenius
splenius cervicis
spleens capitis
origin of splenius (both)
nuchal ligament and spinous process of T1-6 vertebrae
insertion of splenius cervicis
tubercles of transverse processes of C1-C4 vertebrae
splenius capitis
lateral parts of mastoid processes and superior nuchal line
actions of splenius muscles
extend head and neck bilaterally
laterally flex neck
rotate head to side of contracting muscle
innervation of splenius muscles
dorsal rami of spinal nerves
erector spinal group muscles
iliocostalis
logissimus
spinalis
actions of erector spinae group
bilaterally extend vertebral column and head
laterally flex vertebral column
innervation of erector spinae group
dorsal rami of spinal nerves
origin of iliocostalis
broad common tendon attaches to iliac crest, posterior part of scrum, sacroiliac ligaments, sacral and inferior lumbar spinous processes and supraspinous ligament
insertions of laumborum of iliocostalis
ribs 6-12
insertions of thoracis of iliocostalis
ribs 1-6
insertion of cervicis of iliocostalis
ribs 1-6 and posterior tubercles of transferees processes of cervical vertebrae 4-6
origin of longissimus – thoracic
ribs 1-6, same as thoracis of iliocostalis
insertion of longissimus – cervicis
transverse processes of cervicial vertebrae
origin of longissimus – cervicis
transverse processes of cervical vertebrae
insertion of longissimus – capitis
mastoid process
origin of longissimus - capitis
transverse processes of cervical vertebrae
origin and insertion of thoracis of spinalis
spinous processes, insert on spinous processes superior to them
muscles of transcersospinalis group
semispinalis
rotatores
multifidus
innervation of transcerospinalis group
dorsal rami of spinal nerves
action of the semispinalis
extend head, thoracic, and cervical regions, rotates them contralaterally
multifidus
covers and spans vertebral segments
origin on transverse process
insertion on spinous process
action of multifidus
stabilizes vertebrae during localized movements of vertebral column
brevis of rotatores
spans one intervertebral joint
longus of rotatores
spans 2 intervertebral joints
action of rotores
extends head, thoracic, and cervical regions (rotates contralaterally)
innervation of interspinales
dorsal rami of spinal nerves
innervation of intertransversari
dorsal and ventral rami of spinal nerves
innervation of levator costalis
dorsal rami of C8 to T11 s nerves
osteological structures of suboccipital triangle
atlas and axis
muscles of sub occipital region
recuts capitis posterior (major and minor) obliques capitis (inferior and superior)
function of muscles in sub occipital region
mainly posture, aid in extension and rotation of atlantoaxial joint
innervation of muscles in suboccipital region
suboccipital nerve (dorsal rami of C1)
