Flashcards in C1 / Atlas Deck (44)
What is the name of the first cervical vertebra?
What features are lacking at C1?
vertebral body, pedicles, a spinous process and the intervertebral disc
What muscle attaches to the anterior arch of C1?
What ligaments will attach to the anterior arch of C1?
the anterior longitudinal, anterior atlanto-occipital and anterior atlanto-axial ligaments
What is observed on the back of the anterior arch of C1?
the fovea dentis
What is the morphology of the superior articular facet of C1?
they are elliptical, closer together in front and often demonstrate an elevation subdividing the facet surface into two separate surfaces
What is the orientation of the superior articular facet of C1?
backward, upward, medial (BUM)
What is the joint classification of the atlanto-occipital zygapophysis?
synovial (diarthrosis) ellipsoidal joint
What are the morphological characteristics of the inferior articular facet of C1?
asymmetrical, slightly concave or flattened
What is the orientation of the inferior articular facet of C1?
backward, medial, downward (BMD)
What is the joint classification of the atlanto-axial zygapophysis?
synovial plane (diarthrosis arthrodia) joint
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 muscle attach to the lateral mass of C1?
levator scapula, splenius cervicis and rectus capitis anterior
What is the contribution of the posterior arch to the circumference of C1?
about forty percent
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 superior surface modifications of the posterior arch of C1 are present?
groove/sulcus for the vertebral artery and arcuate rim
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?
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?
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?
What is the incidence of a complete ponticulus posticus versus an incomplete ponticulus posticus?
the incidence of a complete ponticulus posticus is about fifteen percent; the incidence of an incomplete ponticulus posticus may be as high as forty-one percent
What joint classification(s) may be observed on the posterior arch of C1?
fibrous (amphiarthrosis) syndesmosis joint