Day 28 (Sacrum, Coccyx, Spondylosis, Spondylolysis, Spondylolisthesis) Flashcards
What forms the inferior boundary for the spinal canal?
the union of the superficial posterior and deep posterior sacrococcygeal ligaments
What ligament divides the sciatic foramen into the greater and lesser sciatic foramina?
sacrospinous ligament
Which ligament has a broad attachment along the lateral margin of sacrum and coccyx and then attaches to the ischial tuberosity?
sacrotuberous 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
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
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
What innervates the coccygeal glomus or coccygeal body?
both sympathetic and parasympathetic fibers are identified
