Sacrum & Coccyx Flashcards
What is the coccygeal glomus or coccygeal body?
An enlarged encapsulated arteriovenous anastomosis located near the last segment of coccyx
What is a ganglion impair?
A midline sympathetic ganglion
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 cornu, 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 the superficial posterior sacrococcygeal and the deep posterior sacrococcygeal ligaments at Co1?
The posterior sacrococcygeal ligament
What ligament divides the sciatic foramen into the greater and lesser sciatic foramen?
Sacrospinous ligament
Which ligament represents a thickening of the fibrous capsule of the sacroiliac joint?
Anterior sacroiliac ligament
Which ligament is the strongest of the sacroiliac ligaments and is penetrated by dorsal rami of the sacral spinal nerves?
Interosseous sacroiliac ligament
Which ligament will attach the intermediate sacral crest of S1, lateral sacral crest of S2 to the posterior superior iliac spine?
Short posterior sacroiliac ligament
Which ligament attaches the lateral sacral crest of S3 and S4 to the posterior superior iliac spine?
Long posterior sacroiliac 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-extension, 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
Superior articular facets of which vertebrae will be oriented backward, upward, and medial?
C1, C3-C7, L1-L5, S1
Superior articular facets of which vertebrae are oriented back, up, medial, and concave?
C1, L1-L5, S1
Superior articular facets of which segments will be oriented backward, upward, and lateral?
C2, T1-T12
Inferior articular facets of which segments will be oriented backward, medial, and downward?
C1
Inferior articular facets of which segments will be oriented forward, lateral, and downward?
C2-C6, T12, L1-L5
Inferior articular facets of which segments are oriented forward, lateral, downward and convex?
T12, L1-L5
Inferior articular facets of which segments will be oriented forward,medial, and downward?
C7, T1-T11
Which segment has the only inferior articular facet to face backward?
C1
What directions will all superior articular facets face?
Backward and upward
Which segments will have facets that are specifically shaped as “concave”?
C1, L1-L5, S1 superior articular facets
Which segments will have facets that are specifically shaped as “convex”?
T12, L1-L5 inferior articular facets
Which segments will have superior articular facets that are oriented medial or inward?
C1, C3-C7, L1-L5, S1
Which segments will have superior articular facets that are oriented lateral or outward?
C2, T1-T12
Which segments will have inferior articular facets that are oriented lateral or outward?
C2-C6, T12, L1-L5
Which segments will have inferior articular facets that are oriented medial or inward?
C1, C7, T1-T11
