Anatomy Second-order Exam 1

Origin, Insertion and Main action of Back Muscles

Latissimus dorsi origin?

spinous process of T7-L5, thoracolumbar fascia, iliac crest, ribs 9-12, and inferior angle of the scapula

Latissimus dorsi insertion?

intertubercular sulcus of humerus

Latissumis dorsi main action?

extends, adducts and medially rotates the arm; assists in respiration

Levator scapulae origin?

transverse process of C1-C4

Levator scapulae insertion?

superior part of medial border of scapula

Levator scapulae main action?

elevates and inferiorly rotates the scapula, bilateral contraction extends the neck, unilateral contraction creates lateral flexion of neck

Rhomboid major origin?

spinous process T2-T5

Rhomboid major insertion?

medial border of scapula from spine to inferior angle

Rhomboid major main action?

retract and elevate scapula, inferior rotation of scapula, stabilize scapula against thoracic wall

Rhomboid minor origin?

nuchal ligament and spinous processes of C7-T1

Rhomboid minor insertion?

medial border of scapula at root of spine

Rhomboid minor main action?

retract and elevate scapula, inferior rotation of scapula, stabilize scapula against thoracic wall

Serratus posterior inferior origin?

spinous process of T11-L2

Serratus posterior inferior insertion?

inferior border of ribs 9-12

Serratus posterior inferior main action?

depresses ribs during exhalation, contribute to forced exhalation

Serratus posterior superior origin?

nuchal ligament, spinal process of C7-T3

Serratus posterior superior insertion?

superior border of ribs 2-5

Serratus posterior superior main action?

elevates ribs during inhalation

Trapezius origin?

external occipital protuberance, superior nuchal line, nuchal ligament, spinous processes and supraspinous ligaments of C7-T12

Trapezius insertion?

lateral third of clavicle, acromion, spine of scapula

Trapezius main action?

elevate, retract, depress, and superiorly rotate scapula

Erector Spinae Muscles origin

posterior/medial part of iliac crest, posterior surface of sacrum, median sacral crest, sacro-iliac ligaments, spinous process of lower lumbar vertebrae, supraspinous ligament

Spinalis cervicis insertion?

spinous process of upper cervical vertebrae

Spinalis cervicis main action?

extends cerebral column

Spinalis thoracis insertion?

spinous process of upper thoracic region

Spinalis thoracis main action?

extends vertebral column

Longissimus capitis insertion?

mastoid process of temporal bone

Longissimus capitis main action?

Bilateral contraction= extends head

Unilateral contraction= ipsilaterally rotates head

Longissimus cervicis insertion?

transverse process of cervical vertebrae

Longissimus cervicis and thoracis main action?

Bilateral contraction= extension and stabilization of vertebral column

Unilateral contraction= lateral flexion of vertebral column

Longissimus thoracis insertion?

transverse process of thoracic vertebrae and ribs

Iliocostalis cervicis, thoracis, lumborum insertion?

angles of lower ribs, transverse process of cervical vertebrae

Iliocostalis cervicis, thoracis, lumborum main action?

Bilateral contraction: extension and stabilization of vertebral column

Unilateral contraction: lateral flexion of vertebral column

Semispinalis capitis origin?

articular process of vertebral column, transverse process of cervical and thoracic vertebrae

Semispinalis capitis insertion?

between superior and inferior nuchal lines of occipital bone

Semispinalis capitis, cervicis, thoracis main action?

Bilateral contraction= extends head and vertebral column

Unilateral contraction= contralateral rotation of head and vertebral column

Semispinalis cervicis insertion?

spinous process of C2-C5

Semispinalis thoracis insertion?

spinous process of lower cervical and upper thoracic vertebrae

Splenius capitis origin?

nuchal ligament and spinous process of C7-T3

Splenius capitis insertion?

mastoid process and lateral third of superior nuchal line

Splenius capitis main action?

Bilateral contraction= extension of the head

Unilateral contraction= lateral flexion and ipsilateral rotation of head

Splenius cervicis origin?

spinous process of T3-T6

Splenius cervicis insertion?

transverse process of C1-C3

Splenius cervicis main action?

Bilateral contraction= extension of cervical spine

Unilateral contraction= lateral flexion and ipsilateral rotation of cervical spine

Multifidus origin?

posterior sacrum, posterior superior iliac spine of ilium, common origin tendon of erector spinae, sacro-iliac ligament, mammillary process of lumbar vertebrae, transverse process of upper thoracic vertebrae, articular process of lower half of cervical vertebrae

Multifidus insertion?

Spinous process 2-4 vertebrae superior to origin

Multifidus main action?

stabilize vertebrae during local movements of vertebral column

Rotatores breves and longi origin?

transverse process of vertebrae

Rotatores breves and longi insertion?

junction of lamina and spinous process of vertebra one level above origin for breves and two for longi

Rotatores breves and longi main action?

stabilize vertebrae, assist with local extension and rotatory movements of the vertebral column

Levatores costarum origin?

transverse process of C7-T11

Levatores costarum insertion?

ribs inferior to origin, between tubercile and angle ribs

Levatores costarum main action?

elevate ribs, assist in respiration, assist in lateral flexion of vertebral column

Intertransversaril origin/insertion?

between transverse processes of adjacent cervical and lumbar vertebrae

Intertransversaril main action?

Bilateral contraction= stabilize vertebral column

Unilateral contraction= aids in lateral flexion of vertebral column

Interspinales origin/insertion?

spinous processes of cervical and lumbar vertebrae

Interspinales main action?

aid in extension and rotation of vertebral column

Obliquus capitis inferior origin?

spinous process of C2(Axis)

Obliquus capitis inferior insertion?

transverse process of C1(Atlas)

Obliquus capitis inferior main action?

ipsilateral rotation of head

Obliquus capitis superior origin?

transverse process of C1(Atlas)

Obliquus capitis superior insertion?

occipital bone between superior and inferior nuchal line

Obliquus capitis superior main action?

Bilateral contraction= extends head

Unilateral contraction= lateral flexion of head

Rectus capitis posterior major origin?

spinous process of C2(Axis)

Rectus capitis posterior major insertion?

inferior nuchal line

Rectus capitis posterior major main action?

Bilateral contraction= extends head

Unilateral contraction= ipsilateral rotation of head

Rectus capitis posterior minor origin?

posterior tubercle of C1(Atlas)

Rectus capitis posterior minor insertion?

medial part of inferior nuchal line

Rectus capitis posterior minor main action?

extends head

What muscle is the exception to the muscle rules?

Levator scapulae