Regions of the Vertebral Column: Sacrum and Coccyx Flashcards
What is the position of the sacral zygapophysis in adults?
The zygapophysis lies in the coronal plane for L5/S1
What is the orientation of the first sacral superior articular facet?
Backward, upward, medial (BUM); typically concave
From the anterior view, the intervetebral discs of sacrum will be replaced by what feature?
Transverse ridges
What forms the median sacral crest?
Fused spinous processes and their spinous tubercles
What forms the intermediate sacral crest?
Fused articular processes and their facets
What features may be identified along the intermediate sacral crest?
The mammillary process of S1 and the sacral cornu of S5
What is the sacral hiatus?
The inferior opening of the sacral spinal canal
An imaginary line drawn from the transverse process of S1 to the inferior lateral sacral angle will form what feature?
The lateral sacral crest
What is the sacral tubersoity?
The enlarges transverse tubercle of S2
What is the name of the joint formed by the sacral tuberosity?
the accessory sacro-iliac joint
What feature is associated with the transverse tubercle of S5?
The inferior and lateral (inferolateral) sacral angle
What feature is identified on the lateral surface of S1-S3?
Auricular surface
What is the sacral promontory?
The bulging anterior surface of the superior epiphyseal rim of S1
How many synovial joints are typically present at sacrum?
Four
What joint classifications are typically present at sacrum?
Fibrous (amphiarthrosis) syndesmosis, cartilaginous (amphiarthrosis) symphysis, and synovial plane (diarthrosis arthrodia)
What forms the posterior boundary for the fifth sacral spinal nerve intervertebral foramen?
Sacral cocrnu, coccygeal cornu, superficial posterior sacrococcygeal ligament and intercornual ligament
What forms the anterior boundary for the fifth sacral spinal nerve intervertebral foramen?
Vertebral body S5, vertebral body Co1, deep posterior sacrococcygeal ligament and intervertebral disc
What is the homolog for the posterior longitudinal ligament at S5?
Deep posterior sacrococcygeal ligament
What is the homolog for the anterior longitudinal ligament at S5?
Anterior sacrococcygeal ligament
What is the homolog for the ligamentum flavum at S5?
Superficial posterior sacrococcygeal ligament
What forms the inferior boundary for the spinal canal?
The union of the superficial posterior and deep posterior sacrococcygeal ligaments
What ligament is formed by the union of ht esuperficial posterior sacrococcygeal and the deep poseterior sacrococcygeal ligaments at Co1?
The posterior sacrococcygeal ligament
What ligament divides the sciatic foramen into the greater and lesser sciatic foramina?
Sacrospinous ligament
Which ligament represents a thickening of the fibrous capsule of the sacro-iliac joint?
Anterior sacro-iliac ligament
Which ligament is the strongest of the sacro-iliac ligaments and is penetrated by dorsal rami of the sacral spinal nerves?
Interosseous sacro-iliac ligament
Which ligament will attach the intermediate sacral crest of S1, lateral sacral crest of S2 to the posterior superior iliac spine?
Short posterior sacro-iliac ligament
Which ligament attaches the lateral sacral crest of S3 and S4 to the posterior superior iliac spine?
Long posterior sacro-iliac ligament
What is the homolog for the inferior articular process and facet at S5?
Sacral cornu
What is the homolog for the superior articular process and facet at Co1?
Coccygeal cornu
What is the homolog for the capsular ligament at S5?
Intercornual ligament
What is the number of coccygeal somites?
Ten
What is the typical number of segments which unite to form the adult coccyx?
4 segments
When is ossification of coccyx completed?
About age 30
What is the direction of fusion of coccygeal segments?
From caudal to cranial, the last segments to fuse together are Co1 and Co2
What is the direction of the coccygeal curve?
Posterior (kyphotic)
What is the major motion and range of motion for coccyx?
Flexion-extensionn, 5-20 degrees
How many coccygeal nerves are present in the fetus?
Typically 5 pairs of coccygeal nerves are present
How many coccygeal nerves are present in the adult?
Typically only one pair of coccygeal nerves remain in the adult
What forms the coccygeal nerve plexus?
S4, S5, and Co1 nerves
What is the ganglion impar?
A midline sympathetic ganglion
What is the coccygeal glomus or coccygeal body?
An enlarged encapsulated arteriovenous anastomosis located near the last segment of coccyx
