muscles of the back Flashcards
intrinsic muscles of the back
superficial deep back muscles, intermediate deep back muscles, deep deep back muscles
extrinsic muscles of the back
superficial, intermediate
what do true back muscles do
mainly act on the spine
extrinsic superficial muscles attach to what
attach the axial skeleton to the appendicular skeleton
extrinsic intermediate muscles do what
superficial respiratory muscles
how many layers of muscles in the back
six
first layer of the back
extrinsic, superficial
trapezius, latissimus dorsi
second layer of the back
extrinsic, superficial
rhomboid major and minor, levator scapulae
third layer of the back
intermediate, superficial
serratus posterior superior and serratus posterior inferior
fourth layer of the back
splenius capitis and splenius cervicis
fifth layer of the back
erector spinae group
sixth layer of the back
transversospinalis group
what is deeper to the sixth layer of the back
suboccipital muscles, intertransversarii muscles, interspinales muscles
how many extrinsic muscles of the back are there
seven in total
how many extrinsic muscles of the back are superficial
five
what are the five superficial extrinsic muscles of the back
trapezius, latissimus dorsi, rhomboid major, rhomboid minor, levator scapulae
descending trapezius origin
medial 1/3 of superior nuchal line of occipital bone, EOP, nuchal ligament, spinous process of C7 vertebra
descending trapezius insertion
lateral 1/3 of clavicle, acromion and spine of scapula
trapezius innervation motor
spinal accessory nerve (cranial nerve XI) (CN eleven)
trapezius innervation sensory
C3, C4 anterior rami of third and fourth cervical nerves
trapezius action
elevates shoulders, pulls shoulder blades together, tilts head backwards
what action happens during unilateral contraction of the trapezius
laterally flexes the head and neck to the same side of contraction
what action happens during bilateral contraction of the trapezius
extends the head and neck
transverse trapezius origin
spinous process of C7-T4 vertebrae
transverse trapezius insertion
acromion of scapula. lateral end of spine of scapula
action of the transverse trapezius
retracts the pectoral girdle at the acromioclavicular amd sternoclavicular joints
ascending trapezius origin
spinous process of T5-T12
ascending trapezius insertion
medial end of spine of scapula
ascending trapezius action
depress, retracts, and upwardly rotates the pectoral girdle, at AC and SC joints
what artery supplies the descending (upper) trapezius
occipital artery
what artery supplies the transverse trapezius
transverse cervical artery
what artery supplies the ascending (lower) trapezius
dorsal scapular artery
latissimus dorsi origin
process of inferior 6 thoracic vertebrae (T7-T12)
thoracolumbar fascia, iliac crest
ribs 9-12
latissimus dorsi insertion
intertubercular sulcus of humerus
latissimus dorsi innervation
thoraco-dorsal nerve
latissimus dorsi action
extends, adducts, and medially rotates the humerus
latissimus dorsi arterial supply
thoracodorsal artery
levator scapulae origin
posterior tubercle of C1-C4 TP
levator scapulae insertion
medial border of scapula, superior to the root of the scapular spine, superior angle of scapula
levator scapulae innervation
anterior rami of third and fourth cervical nerves(sensory) , dorsal scapular nerve (motor)
levator scapulae action
elevates shoulders, pulls shoulder blades together, extends and laterally flexes the neck
levator scapulae arterial supply
transverse cervical
rhomboid major origin
spinous process of the 2-5th thoracic vertebrae
rhomboid major insertion
medial border of scapula inferior to the level of the spine of scapula
rhomboid major innervation
dorsal scapular nerve
rhomboid major arterial supply
dorsal scapular artery
rhomboid major action
retract scapula and rotate glenoid cavity inferiorly, fix scapula to thoracic wall
rhomboid minor origin
spinous processes of C7-T1
rhomboid minor insertion
medial scapular spine above the spine of the scap
rhomboid minor innervation
dorsal scapular nerve
rhomboid minor action
retracts and downwardly rotates pectoral shoulder girdle, fix scapula to thoracic wall
serratus posterior superior origin
nuchal ligament, spinous process of C7-T3
serratus posterior superior origin
superior border second to fifth ribs
serratus posterior superior innervation
anterior rami of second to fifth thoracic nerves (intercostal nerves 2-5)
serratus posterior superior action
elevate ribs, proprioception
serratus posterior inferior origin
spinous process of T11-L2
serratus posterior inferior insertion
external surfaces of ninth to twelfth ribs
serratus posterior inferior action
depressed ribs, proprioception
serratus posterior arterial supply
dorsal branches of lower posterior intercostal arteries and subcostal artery
splenius capitis insertion
mastoid process of temporal bone, lateral 1/3 of superior nuchal line of occipital bone
splenius capitis origin
nuchal ligament and spinous process of C3-T3 vertebrae
splenius capitis innervation
dorsal rami
splenius capitis action
rotate and extend the head, laterally flex the neck and rotate the head to the side of active muscles
splenius cervicis origin
spinous of T3-T6 vertebrae
splenius cervicis insertion
transverse process of C1-C3 vertebrae
splenius cervicis innervation
dorsal rami
splenius cervicis arterial supply
descending branch of occipital artery and deep cervical artery
splenius cervicis action
extends, rotates, and laterally flexes the neck at cervical vertebral joints
bilaterally: extends the head and neck
what muscles make up the erector spinae group aka sacrospinalis group
iliocostalis, longissimus, spinalis
iliocostalis cervicis origin
angles of third to sixth ribs
iliocostalis cervisis insertion
posterior tubercle of TP of C4-C6
iliocostalis cervicis innervation
dorsal rami
iliocostalis cervicis action
extends and laterally flexes neck
iliocostalis thoracis origin
angles of seventh to twelfth ribs
iliocostalis thoracic insertion
angles of first - sixth ribs
iliocostalis thoracic innnervation
dorsal rami
iliocostalis thoracic action
extends and laterally flexes the trunk
iliocostalis lumborum origin
iliac crest, posterolateral aspect of sacrum
iliocostalis lumborum insertion
TP of L1-L4, angles of fifth to tenth ribs
iliocostalis lumborum innervation
dorsal rami
iliocostalis lumborum action
extends and laterally flexes the trunk
longissimus capitis origin
TP of C4-T4
longissimus capitis insertion
mastoid process of temporal bone
longissimus capitis innervation
dorsal rami
longissimus capitis action
extends, rotates, laterally flexes the head
longissimus cervicis origin
TP of T1-T6
longissimus cervicis insertion
TP of C2-C6
(posterior tubercles)
longissimus cervicis innervaton
dorsal rami
longissimus cervicis action
extends and laterally flexes neck
longissimus thoracis origin
SP of L1-L5, dorsal surface of sacrum and iliac crest
longissimus thoracis insertion
TP of lumbar and thoracic vertebrae, 2-12 ribs
longissimus thoracis innervation
dorsal primary rami
longissimus thoracis action
extend and laterally flex the trunk
spinalis thoracis origin
SP of T11-L3
spinalis thoracis insertion
SP of T2-T8
spinalis thoracis action
extend and laterally flex the trunk
semispinalis capitis origin
superior articular processes of C4-C7 vertebrae, TP of T1-T6 vertebrae
semispinalis capitis insertion
area between superior and inferior nuchal lines of occipital bone
semispinalis capitis action
extends and rotates the head
semispinalis cervicis origin
TP of T1-T6
semispinalis cervicis insertion
SP of C2-C5
semispinalis cervicis action
extend and rotate the neck
semispinalis thoracis origin
TP of T6-T11
semispinalis thoracis insertion
SP of C6-T4
semispinalis thoracis action
extend and rotate the trunk
multifidus origin
PSIS, dorsal sacrum, mammillary processes of lumbar, TP of thoracic, articular processes of C4-C7
multifidus insertion
SP of lumbar, thoracic, and cervical vertebrae
multifidus action
extends neck and trunk, stabilizes vertebral column
long rotatores origin
TP of thoracic
long rotatores insertion
laminae and SP of thoracic vertebrae 2 vertebral segments above
long rotatores action
extends and rotates trunk, stabilizes vertebral column
rectus capitis posterior minor origin
posterior arch of atlas
rectus capitis posterior minor insertion
inferior nuchal line of occipital bone
rectus posterior capitis minor action
extend head
rectus posterior capitis major origin
SP of axis (C2)
rectus capitis posterior major insertion
inferior nuchal line of occipital bone
rectus capitis posterior major action
rotates and extends head
obliquus capitis inferior origin
SP of axis
obliquus capitis inferior insertion
TP of atlas
obliquus capitis inferior action
rotates head
obliquus capitis superior origin
TP of atlas
obliquus capitis superior insertion
posterior aspect of occipital bone
obliquus capitis superior action
laterally flexes and extends head
