8/17 Questions Exam 2 Flashcards
What part of C1 represents the spinous process?
posterior tubercle of the posterior arch
What is the distance from the posterior tubercle of the posterior arch to the skin in each gender?
males: about fifty millimeters
Females: about thirty-seven millimeters
What attaches to the posterior tubercle of the posterior arch of C1?
rectus capitis posterior minor muscle and ligamentum nuchae
What attaches to the arcuate rim of C1?
the posterior atlanto-occipital ligament
Ossification of the free margin of the posterior atlanto-occipital ligament results in which atypical bone classification?
accessory bone
What is the earliest age of development where ossification of the anterior free margin of the posterior atlanto-occipital ligament was observed?
about age 7 years old
What may be formed by ossification of the anterior free margin of the posterior atlanto-occipital ligament?
a partial ponticulus posticus or complete ponticulus posticus
What other name may be used to identify a ponticulus posticus?
kimmerle’s anomaly
What names are given to the opening formed by the ponticulus posticus?
arcuate foramen or retroarticular canal
Ponticulus posticus has observed in what ethnic populations?
all ethnic populations studied thus far
What is the general range of incidence of ponticulus posticus in the populations studied?
1% - 41%
What is the gender bias now associated with ponticulus posticus?
Female
What is the locations of the “zygapophysis” relative to the atlanto-occipital and atlanto-axial intervertebral foramina?
it forms part of the anterior boundary of the intervertebral foramen in both cases
What are the osseous parts of the transverse process of C1?
costal element, posterior tubercle, true transverse process
What osseous parts of the transverse process are absent at C1?
anterior tubercle and costotransverse bar
What muscles attach to the transverse process of C1?
Rectus capitis anterior Rectus capitis lateralis Middle scalene Levator scapula splenius cervicis obliquus capitis superior obliquus capitis inferior intertransversarii muscles
What suboccipital muscles are known to have fascial projections attaching to the spinal dura?
rectus capitis posterior minor
rectus capitis posterior major
obliquus capitis inferior
What are the connections between suboccipital muscles and the spinal dura called?
myodural bridges
What are the lateral bridges of atlas connected to?
the lateral mass and the transverse process of atlas
What opening is identified when a complete lateral bridge is formed?
the retrotransverse foramen
What are the possible contents of the retrotransverse foramen?
the vertebral artery, a branch from the suboccipital nerve and veins communicating with the venous sinuses of the neck
Which of the ponticles (bridges) of atlas is most numerous?
ponticulus posticus
Which of the ponticles (bridges) of atlas is only observed in humans?
lateral bridges
What is observed in the transverse foramen of C1?
vertebral artery
Vertebral venous plexus
Postganglionic sympathetic motor nerve fibers
What is the gender variation for measurements of the transverse diameter of C1?
males: 78 millimeters
females: 72 millimeters
What is the distance from the posterior tubercle of the transverse process of C1 to the skin for each gender?
a little over 30 millimeters for both males and females
What is the contribution of the posterior arch to the circumference of C1?
about forty percent
