Day 16 (C1/Atlas) Flashcards
What is thought to represent the pedicle at C1?
the anterior arch
What is the name of the rounded elevation on the medial aspect of the lateral mass of C1?
tubercle for the transverse atlantal ligament
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% - 4%
What is the gender bias now associated with ponticulus posticus?
female
What is the location 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
