Unit III - Atlas, Axis, and Cervical vertebrae C3-C7

Question 1

What are the parts of the axis?

Answer 1

body

dens

neural arch

Question 2

What are the parts of the body of the axis?

Answer 2

superior articular facet (articulates with the atlas)

Question 3

What are the parts of the dens of the axis?

Answer 3

impressions for the alar ligament

groove for the transverse ligament

Question 4

What does the alar ligament attach to and what is its function?

Answer 4

attachments: dens –> medial aspect of occipital condyles
function: limits rotation of median atlanto-axial joint

Question 5

What does the transverse ligament attach to and what is its function?

Answer 5

attachment: lateral mass –> lateral mass of atlas
function: maintains articulation between dens and anterior arch of atlas

Question 6

What are the parts of the neural arch of the axis?

Answer 6

pedicle

lamina

spinous process

Question 7

What are the parts of the pedicle?

Answer 7

Vertebral notch (transmits C3 spinal nerve)

Transverse process (levator scapulae & middle scalene attach)

Transverse foramen (transmits vertebral a. & v.)

Question 8

What muscles attach to the transverse process of the axis?

Answer 8

(1) levator scapulae

(2) middle scalene
attachment: transverse processes of cervical vertebrae –> 1st rib
function: elevation of 1st rib during forced inspiration and lateral flexion of neck
innervation: ventral rami of cervical spinal n.
blood supply: ascending cervical, suprascapular and transverse cervical a.

Question 9

What muscles attach to the spinous process of the axis?

Answer 9

(1) semispinalis cervicis
attachment: upper thoracic transverse processes –> cervical spinous processes
function: extension of neck
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, deep cervical, deep branch of transverse cervical a.

(2) rectus capitis posterior major
attachment: spinous process of axis –> adjacent occipital bone
function: extension of head
innervation: suboccipital n. (dorsal ramus C1)
blood supply: vertebral and occipital a.

(3) obliquus capitis inferior
attachment: spinous process of axis –> transverse process of atlas
function: ipsilateral rotation of head
innervation: suboccipital n. (dorsal ramus C1)
blood supply: vertebral & occipital a.

Question 10

What muscles attach to the transverse processes of the cervical vertebrae C3-C7?

Answer 10

(1) longus capitis
attachment: anterior tubercles of transverse processes of cervical vertebrae –> basilar occipital bone
function: flexion of head & neck
innervation: ventral rami of cervical spinal n.
blood supply: vertebral, ascending cervical, ascending pharyngeal & inferior thyroid a.

(2) longus colli
attachment: cervical vertebral bodies –> cervical vertebral bodies & transverse processes
function: flexion of neck
innervation: ventral rami of cervical spinal n.
blood supply: vertebral, ascending pharyngeal, inferior thyroid a.

(3) scalenus anterior
attachment: transverse processes of middle cervical vertebrae –> scalene tubercle of 1st rib
function: elevation of 1st rib during forced inspiration, flexion & rotation of neck
innervation: ventral rami of cervical spinal n.
blood supply: ascending cervical, suprascapular & transverse cervical a.

(4) scalenus medius
attachment: transverse processes of cervical vertebrae –> 1st rib
function: elevation of 1st rib during forced inspiration, lateral flexion of neck
innervation: ventral rami of cervical spinal n.
blood supply: ascending cervical, suprascapular & transverse cervical a.

(5) scalenus posterior
attachment: lower cervical transverse processes –> 2nd rib
function: elevation of rib during forced inspiration
innervation: ventral rami of cervical spinal n.
blood supply: ascending cervical, suprascapular & transverse cervical a.

(6) semispinalis capitis
attachment: upper thoracic & cervical transverse processes –> occipital bone between inferior & superior nuchal lines
function: extension of head
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, occipital, deep cervical, deep branch of transverse cervical a.

(7) splenius cervicis
attachment: spinous processes of upper thoracic vertebrae –> transverse processes of upper 3 cervical vertebrae
function: together extend neck, single side does ipsilateral rotation
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, occipital, deep cervical, deep branch of transverse cervical a.

Question 11

What muscle attaches to the C3-C7 vertebral bodies?

Answer 11

longus coli muscle

attachment: cervical vertebral bodies –> cervical vertebral bodies & transverse processes
function: flexion of neck
innervation: ventral rami of cervical spinal n.
blood supply: vertebral, ascending pharyngeal, inferior thyroid a.

Question 12

What muscles attach to the spinous processes of cervical vertebrae C3-C7?

Answer 12

(1) splenius capitis
attachment: ligamentum nuchae & lower cervical & upper thoracic spinous processes –> lateral 1/3rd of superior nuchal line
function: extension & lateral flexion of head
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, occipital, deep cervical & deep branch of transverse cervical a.

(2) splenius cervicis
attachment: spinous processes of upper thoracic vertebrae –> transverse processes of upper 3 cervical vertebrae
function: together extend neck, single side does ipsilateral rotation
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, occipital, deep cervical, deep branch of transverse cervical a.

(3) semispinalis cervicis
attachment: upper thoracic transverse processes –> cervical spinous processes
function: extension of neck
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, deep cervical & deep branch of transverse cervical a.

Question 13

What muscle attaches to BOTH the transverse and spinous processes of cervical vertebrae C3-C7?

Answer 13

splenius cervicis

attachment: spinous processes of upper thoracic vertebrae –> transverse processes of upper 3 cervical vertebrae
function: together extend neck, single side does ipsilateral rotation
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, occipital, deep cervical, deep branch of transverse cervical a.

Question 14

What are the four parts of the atlas?

Answer 14

anterior arch (anterior tubercle)

lateral masses (superior facet–articulates with occipital condyles, inferior facet–articulates with axis)

posterior arch (groove for vertebral artery, posterior tubercle)

transverse process (transverse foramen

Question 15

What attaches to the anterior tubercle of the atlas?

Answer 15

anterior longitudinal ligament

longus colli muscle

Question 16

What is housed in the groove for the vertebral artery of the atlas?

Answer 16

vertebral artery & vein

suboccipital nerve

Question 17

What attaches to the posterior tubercle of the atlas?

Answer 17

ligamentum nuchae

attachment: C7 spinous process –> external occipital protuberance with slips to intervening spinous processes
function: attachment for cervical muscles

rectus capitis posterior minor muscle
attachment: posterior tubercle of atlas –> adjacent occipital bone
function: extension of head
innervation: suboccipital n. (dorsal ramus C1)
blood supply: vertebral & occipital a.

Question 18

What attaches to the transverse process of the atlas?

Answer 18

(1) levator scapulae

(2) obliquus capitis inferior
attachment: spinous process of axis –> transverse process of atlas
function: ipsilateral rotation of head
innervation: suboccipital n. (dorsal ramus C1)
blood supply: vertebral & occipital a.

(3) obliquus capitis superior
attachment: transverse process atlast –> occipital bone between superior & inferior nuchal lines
function: posterolateral flexion of the head
innervation: suboccipital n. (dorsal ramus C1)
blood supply: vertebral & occipital a.

Question 19

What transmits the vertebral artery & nerve?

Answer 19

Transverse foramen of the atlas