C1/ Atlas Flashcards
what is the name of the first cervical vertebra
atlas
what features are lacking at C1
vertebral body, pedicles, a spinous process and the intervertebral disc
what is thought to represent the pedicle at C1
the anterior arch
what osseous modification is observed to the front of the anterior arch of C1
anterior tubercle
what muscle attaches to the anterior arch of C1
longus colli
what ligaments will attach to the anterior arch of C1
anterior longitudinal, anterior atlanto-occipital and anterior atlanto-axial ligaments
what is observed on the back of the anterior arch of C1
fovea dentis
what joint classifications are observed on the anterior arch of C1
amphiarthrosis syndesmosis and diarthrosis trochoid
what is the contribution of the lateral mass to the circumference of C1
forty percent; twenty percent for each lateral mass
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
diathrosis ellipsoidal
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
diarthrosis arthrodia
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 muscles 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 40 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 50 mm
females- about 37 mm
what attaches to the posterior tubercle of teh posterior arch of c1
rectus capitis posterior minor muscles 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
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
with regard to ossification of the posterior atlanto- occipital ligament, what is the gender bias, bone classification, amount of ossification and general percent in the population
male- accessory bone, complete ponticulus posticus, 15%
female- accessory bone, partial ponticulus posticus, 26%
what is observed on the undersurface of the posterior arch of c1
“inferior vertebral notch” and an attachment site for the posterior atlanto-axial ligament
what joint classification (s) may be observed on the posterior arch of C1
amphiarthrosis syndesmosis
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 is the general appearance of the transverse process of c1
triangular
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 and intertransversarii muscles
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 distance from the posterior tubercle of the transverse process of c1 to the skin
not a significant difference
what is the distance from the posterior tubercle of the transverse process of c1 to the skin for each gender
a little over 3o mm for both
what joint classifications are observed at c1
amphiarthrosis syndesmosis, diarthrosis ellipsoidal, diarthrosis trochoid, diarthrosis arthrodia
how many synovial joint surfaces are observed at c1
5
what synovial joint surfaces are observed at c1
two superior articular facets, two inferior articular facets and the fovea dentis
what is the gender variation for measurements of the transverse diameter of c1
males- 78 mm
females- 72 mm
