Coccyx Flashcards
What is the number of coccygeal somites
ten
What is the typical number of segments that unite to form the adult coccyx?
4 segments
When is ossification of coccyx completed?
30 years old
What bony features are present on the coccyx?
all segments are represent by a “vertebral body”; Co1 has a coccygeal cornu and transverse process
What is the homolog of the superior articular process and facet on Co1?
coccygeal cornu
What is the major motion and range of motion for coccyx?
flexion - extension, 2-20 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 location of the ganglion impar?
anywhere from the sacrococcygeal joint to the upper thrid of the coccyx
What is the coccygeal gloms or coccygeal body?
an enlarged encapsulated arteriovenous anastomosis located near the last segment of the coccyx
What muscles attach to the coccyx?
ischiococcygeus and levator ani
What forms the inferior boundary for the spinal canal?
the union of the superficial posterior and deep posterior sacrococcygeal ligaments
What is the homolog for the capsular ligament at Co1?
intercornual ligament
