Suboccipital Region Flashcards
innervation to skin of suboccipital region?
greater + lesser occipital nerves
just learn table
superficial + intermediate muscles of suboccipital region?
Most superficial muscle = trapezius, also part of levator scapulae + sternocleidomastoid
The muscle layer beneath them = intermediate layer —> splenius capitis and cervicis
label superficial + intermediate muscles of suboccipital region
splenius capitis attachments?
cervicis?
Innervation?
Function?
Splenius capitis = ligamentum nuchae + C7-T3 spinous processes to —> occipital bone (superior nuchal) + mastoid
Splenius cervicis = T3-T6 spinous processes to —> C1-C2 transverse processes
Innervation = posterior rami C1-C6
Bilateral = extend neck and head Unilateral = flexes and rotates to same side
Beneath splenius capitis and cervicis?
Attachments?
Function?
Innervation?
semispinalis capitis + longissimus capitis
semispinalis capitis = C4-T7 transverse processes to ---> occipital (between nuchal lines) function = extends cervical spine (both), bends to same side and rotates to opposite side
longissumus capitis = C4-T3 transverse processes to ---> mastoid process function = extends head (both), flexes and rotates head oto same side
innervation = posterior rami
label
4 muscles that attach to mastoid?
sternocleidomastoid, the posterior belly of digastric, splenius capitis and longissimus capitis
which muscles lie deep to splenius capitis, cervicis, semispinalis capitis + longissimus capitis? Found? Function? innervation?
The suboccipital muscles
Found between C2, C1 + occipital bone
function = extend head all innervated by suboccipital nerve (one each side) which originates from posterior ramus of C1
label muscles
muscle group?
suboccipital muscles
label muscles A + B
A = rectus capitis posterior major B = rectus capitis posterior minor
rectus capitis posterior major + minor attachments?
Function?
Innervation?
Major = C2 spinous process to ---> inferior nuchal line Minor = C1 posterior tubercle to ---> inferior nuchal line
Extend head (both), rotate to same side (one)
Suboccipital nerve (posterior rami of C1)
(major is larger and more lateral)
muscles found lateral to rectus capitis muscles?
Attachments?
Function?
Innervation?
obliquus capitis muscles
obliquus capitis superior = C1 transverse process to occipital (above inf. nuchal) function = extends head (both), tilts head to same side, rotates to opposite side (one)
obliquus capitis inferior = C2 spinous process to C1 transverse process function = extends head (both) and rotates to same side (one)
innervation = suboccpital nerve (posterior rami C1)
label
label muscles A + B
A = obliquus capitis superior B = obliquus capitis inferior
function?
suboccipital (C1) = motor to suboccipital muscles greater occipital (C2) = skin C3 dorsal ramus = skin + muscles of neck
label A, B + C
A = suboccpital (C1) B = greater occpital (C2) C = dorsal ramus (C3)
label arteries
arterial supply suboccpital region?
joins?
occipital artery - sends descending branch to anastamose with deep cervical artery from subclavian
where is vertebral artery found?
The vertebral arteries lie within the ’suboccipital triangle’ bounded by obliquus capitis muscles and rectus capitis posterior major
vertebral arteries branch from?
found in neck?
pathway?
branch of subclavian in root of neck
ascend neck in foramen transversarium of cervical vertebra
cross superior surface of C1 to enter foramen magnum
R + L vertebral arteries unite to form the basilar artery (joins Circle of Willis to supply the brain)
what runs with the suboccpital nerve?
Drain into?
Occipital veins run with the suboccipital nerve
Occipital veins –> deep cervical vein —> vertebral veins —> subclavian/brachiocephalic vein
posterior vertebral venous plexus?
drains into?
Communications with occipital veins, emissary veins of the skull, longitudinal vertebral venous sinus (LVVS), veins around the vertebral artery
drain into brachiocephalic vein (via the deep cervical vein)
nodding “yes” head motion occurs between?
shaking head “no:?
head nodding ‘yes’ movement = between atlas (C1) + occipital condyles of the skull
head shaking ‘no’ = arch of the atlas + dens of axis (C2)
label ligaments and membranes of suboccipital region
cruciate ligament also called?
Formed from?
Cruciate ligament also called cruciform
= transverse ligament of atlas + superior and inferior longitudinal ligament bands
(form a cross shape between the axis and the occipital bone)
alar ligament attachments?
alar ligament = from dens of C2 to —> medial sides of occipital condyles
learn summary
….
muscles involves in ipsilateral vs contralateral rotation of head?
how many cervical vertebrae?
cervical vertebrae appearance?
C1-C7
C3-C6 = ‘typical’ in shape with bifid spinous process + foramen transversarium in each transverse process
C1, C2 + C7 = atypical
C1 = no body as it articulates with the skull via the occipital condyles and with the axis via a facet on its anterior arch
C2 = has a large spinous process and odontoid process that articulates with atlas
C7 = large nonbifid spinous process, ‘vertebra prominens’
muscles involved in flexion, extension, lateral bending + rotation of the neck?
Photograph A shows the suboccipital region of the neck. The left side has only had the skin removed to reveal trapezius muscle. The right side has been dissected to show the muscles of the suboccipital region.
This slide shows a step-wise dissection from superficial (photograph A) to deep (photograph C).
Trapezius is the most superficial muscle and it passes towards the superior nuchal line of the occipital bone (photograph A). It acts to move the scapula and is innervated by the spinal accessory nerve (CN IX).
Photograph B shows the next muscle layer immediately beneath trapezius – splenius capitis. It attaches to the spinous processes of C7 to T3 and to the occipital bone and mastoid process. It acts to extend the neck and is innervated by the cervical dorsal rami.
Photograph C shows splenius capitis reflected to reveal semispinalis capitis. This muscle passes between the transverse processes of the cervical vertebrae and the occipital bone (between the nuchal lines). It acts to extend the neck and is innervated by the cervical dorsal rami nerves.
Photograph A shows a deep dissection where semispinalis capitis has been reflected to reveal some of the dorsal rami nerves. These nerves supply motor innervation to the extensor muscles of the neck and also supply the skin of the posterior surface of the neck with sensory innervation. C2 forms the greater occipital nerve.
Photograph B shows other structures that can be seen at the same level as photograph A. The dorsal ramus of C1 forms the suboccipital nerve that supplies the suboccipital muscles that extend the head on the neck. The occipital vein runs with the suboccipital nerve and joins the deep cervical vein.
The suboccipital muscles collectively act to extend the head and are all innervated by the suboccipital nerve.
There are four muscles on each side – rectus capitis posterior major and minor and obliquus capitis superior and inferior.
Photograph A shows rectus capitis posterior major and photograph B shows rectus capitis posterior minor. The names of the muscles tells you the make the head erect (extend the head), are found on the posterior surface of the body and there is one large and one small muscle. Major passes between the spinous process of the axis (C2) and the inferior nuchal line of the occipital bone, minor between the posterior tubercle of the atlas (C1) and the inferior nuchal line of the occipital bone.
Photograph A shows obliquus capitis inferior that attaches to the spinous process of the axis (C2) and the transverse process of the atlas (C1). Photograph B shows obliquus capitis superior that attaches to the transverse process of the atlas and the occipital bone (above the inferior nuchal line).
This slide shows all four muscles on the right side, plus you can just see the tendon of the left rectus capitis posterior minor muscle attaching to the atlas.
Photographs A and B show very deep dissections of the suboccipital region. Photograph A shows the C1 dorsal ramus as it emerges above the atlas. It sits very close to the vertebral artery as the artery loops over the superior surface of the atlas to pass into the foramen magnum, where left and right vertebral arteries unite to form the basilar artery. The basilar artery joins the circle of Willis to supply the brain with blood.
Photograph B shows the dorsal ramus of C2 as it passes beneath the atlas.
