Atlas of Human Anatomy by Netter

thoracic and cervical vertebrae, and

mastoid process

Spinalis: spinous processes of upper

thoracic and midcervical vertebrae

region

SemispinalisTransverse processes C4-T12 Spinous processes of cervical and

thoracic regions

Respective

spinal

nerves of

each

region

Extend head, neck,

and thorax and

rotate them to

opposite side

Multifidi Sacrum, ilium, and transverse processes

of T1-T12, and articular processes of C4-

C7

Spinous processes of vertebrae above,

spanning two to four segments

Respective

spinal

nerves of

each

region

Stabilizes spine

Rotatores Transverse processes Lamina and transverse process or

spine above, spanning one or two

segments

Respective

spinal

nerves of

each

region

Stabilize, extend,

and rotate spine

Fascia

Encloses deep muscles of the back

Attached medially to the nuchal ligament, tips of the spinous processes, supraspinous ligament, and median line of sacrum

Attached laterally to the cervical and lumbar transverse processes

Thickened as the thoracolumbar fascia toward lumbar region and extends between the twelfth rib and the iliac crest

Vascular supply to muscles and skin of the back

Arteries

Cervical: branches from occipital, ascending cervical, vertebral, and deep cervical

Thoracoabdominal: branches of posterior intercostals, subcostal, and lumbar

Pelvic: iliolumbar and lateral sacral branches of the internal iliac

Veins drain via the valveless vertebral venous plexus

Lymph

Neck: Drains to the anterior, lateral, and deep cervical nodes

Trunk: drains to axillary nodes above umbilicus and superior inguinal nodes below it

Suboccipital region

Inferior to the occiput, deep to the trapezius and semispinalis capitis, overlying C1 and C2

Muscles

Rectus capitis posterior minor and major

Obliquus capitis superior and inferior

All laterally flex, extend, and rotate the head

All supplied by the suboccipital nerve (dorsal ramus of C1)

Contains the dorsal rami of C1-C4

Suboccipital triangle

Contains the vertebral artery, suboccipital nerve and suboccipital venous plexus.

Bounded by rectus capitis posterior major, obliquus capitis superior and obliquus capitis inferior, floor-atlantooccipital membrane,

roof-semispinalis capitis

Deep Layer

Muscle Proximal Attachment

(Origin)

Distal Attachment

(Insertion)

Innervation Main Actions

Rectus capitis posterior

major

Spine of axis Lateral inferior nuchal

line

Suboccipital nerve

(C1)

Extends head and rotates to

same side

Rectus capitis posterior

minor

Tubercle of posterior arch

of atlas

Median inferior nuchal

line

Suboccipital nerve

(C1)

Extends head

Obliquus capitis

superior

Transverse process of

atlas

Occipital bone Suboccipital nerve

(C1)

Extend head and bend it laterally

Obliquus capitis inferiorSpine of axis Atlas transverse

process

Suboccipital nerve

(C1)

Rotates atlas to turn face to

same side

Branches of spinal nerves

Ventral rami innervate the muscles and overlying skin of the anterior thoracic, abdominal and pelvic wall and contribute to

Cervical plexus [C1-C4] (see: Head and Neck)

Brachial plexus [C5-T1] (see: Upper Limb)

Thoracic intercostal nerves (see also: Thorax)

Lumbar plexus [T12-L4] (see: Pelvis and Perineum and Lower Limb)

Sacral plexus [L4-S5] (see: Lower Limb)

Dorsal rami

C1: Suboccipital nerve-pierces the atlantooccipital membrane and is motor to the suboccipital muscles

C2: Greater occipital nerve-passes inferior to OCI and is sensory to skin over neck and occipital bone