sacrum outline Flashcards
the sacrum is composed of how many vertebral segments?
5 on average
what is the shape of the sacrum?
triangular
the sacrum is concave on what surface?
anterior
the base of the sacrum is composed of what?
S1
what is the shape of S1 from a superior view?
reniform
the vertebral body of S1 has a distinct superior epiphyseal rim and what type of center?
spongy bone center
the pedicle of S1 is short and extends in what direction?
extending posteriorly, with little lateral deviation
the superior vertebral notch of S1 is formed from the superior edge of what?
pedicle
laterally the pedicle of S1 is continous with what?
transverse process
the vertebral foramen of S1 is what shape?
triangular
the vertebral foramen of S1 starts the?
sacral canal
what is the sacral ala?
a highly modified transverse process
what forms the anterior two-thirds of the sacral ala?
costal element
what forms the posterior third of the sacral ala?
true transverse process
what direction does the superior articular facet of S1 face?
Back, up, medial (BUM)
what is variably present on the superior articular process of S1?
mamillary process
the spinous tubercle of S1 is found at the union of what?
right and left laminae
what makes up the pelvic surface division of the sacrum?
the vertebral bodies of S1-S5, separated by transverse ridges
the anterior sacral foramina is the exit for?
ventral primary rami of S1-S4 spinal nerves
the costal element of the lateral sacral mass is visible at what vertebral levels?
S1
S2
S3
the true transverse process of the lateral mass is visible at what vertebral levels?
S4
S5
the anterior protrusion of the superior epiphyseal rim and upper vertebral body of S1 is known as?
sacral promontory
on the dorsal surface, the posterior sacral foamina is the exit for?
dorsal primary rami of S1-S4
what are the three longitudinal crests on the longitudinal posterior division of the sacrum?
median crest
intermediate crest
lateral crest
the median sacral crest is located midsagittally and is formed by what?
fused sacral spinous processes/tubercles of S1-S4
the intermediate sacral crest is located just lateral to the median sacral crest and is formed by?
fused articular process of S1-S5
the sacral cornu of S5 is the termination of what?
the intermediate sacral crest
the sacral cornu is formed from?
modified inferior articular process of S5
what is the opening found between the right and left sacral cornuae?
sacral hiatus
exit of the sacral canal
the lateral sacral crest is located lateral to the dorsal sacral foramina and formed from?
fused transverse tubercles of S1-S5
what does the lateral sacral crest begin with?
sacral tubercle
and
sacral tuberosity
what is the sacral tubercle?
the transverse tubercle of S1
what is the sacral tuberosity?
the transverse tubercle of S2
where does the lateral crest end?
ends at the inferior sacral angle
what three things can be found on the lateral surface of the sacrum?
auricular surface
costal element
true transverse process
the auricular surface of the sacrum is the articular surface for synovial joint with what?
auricular surface of the ilium
the auricular surface covers most of the lateral surface through what vertebral levels?
S1-S3
the auricular surface is contained entirely within what part of the lateral surface of sacrum?
costal element
what is the triangular area covering the antero-lateral surface of S1-S3 and tapers to an end inferior of the auricular surface?
costal element
Easy one!
what is the part of the lateral surface located posterior to the costal element, extending from S1 to S5?
true transverse process
what makes up the inferior portion of the vertebral body and inferior epiphyseal rim of S5?
Apex
what extends from the vertebral foramen of S1 to the sacral hiatus at the level of S5?
sacral canal
what does the coccyx consist of?
consists of 3-5 rudimentary vertebral segments
each vertebrae of coccyx has how many ossification centers?
1 center of ossification
superior and inferior surfaces of the Co1 vertebrae may resemble what?
superior and inferior epiphysesal rims
Co1 has a transverse process that is small and rudimentary, projecting?
laterally
what part of Co1 projects superiorly and formed from rudimentary superior articular process?
coccygeal cornu
Co2-Co5 consists of what?
rudimentary vertebral bodies
