Unit III - Occipital bone Flashcards
What are the three parts of the occipital bone?
Squama
Basilar part
Lateral part
What are the 7 parts of the squama?
external occipital protuberence
superior nuchal line
inferior nuchal line
internal occipital protuberence
superior sagittal sulcus
sulcus for transverse sinus
sulcus for sigmoid sinus
What attaches to the external occipital protuberence?
ligamentum nuchae
attachment: C7 spinous process –> external occipital protuberance with slips to intervening spinous processes
function: attachment for cervical muscles
What muscles attach to the superior nuchal line?
(1) trapezius
(2) sternocleidomastoid
attachment: lateral aspect of mastoid process and superior nuchal line –> manubrium and medial 1/3 clavicle
function: flexion of head and neck, contralateral rotation of head
innervation: accessory n.
blood supply: occipital, posterior auricular, superior thyroid, suprascapular a.
(3) 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.
(4) 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.
What muscles attach to the inferior nuchal line?
(1) 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 & occipital a.
(2) rectus capitis posterior minor
attachment: posterior tubercle of atlas –> adjacent occipital bone
function: extension of head
innervation: suboccipital n. (dorsal ramus C1)
blood supply: vertebral & occipital a.
(3) 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.
What muscles attach to the internal occipital protuberence?
falx cerebelli
What are the two parts of the basilar part of the occipital bone?
foramen magnum
pharyngeal tubercle
What muscle attaches to the basilar part of the occipital bone?
longus capitis
What is transmitted through the foramen magnum?
spinal cord, vertebral a. & v., accessory nerve
What attaches to the pharyngeal tubercle?
pharyngeal raphe
What are the three parts of the lateral part of the occipital bone?
Occipital condyles
hypoglossal canal
jugular notch & foramen
What is transmitted through the hypoglossal canal?
hypoglossal nerve
What is transmitted through the jugular notch & foramen
internal jugular v., glossopharyngeal n., vagus n., accessory n.
