Sacrum & Coccyx
Although the size and degree of curvature of the sacrum vary considerably in different patients, the bone is normally _____
longer, narrower, more evenly curved, and more vertical in position in males than in females
The coccyx is composed of ___-____ rudimentary vertebrae that have a tendency to fuse into one bone in the adult
3-5 (usually four)
The female sacrum is more ____ curved, with its greatest curvature in the ___ half of the bone, ,which results in ___
acutely lower a sharper angle at the junction of the lumbar and pelvic curves
On each side of the sacral base is a large, winglike lateral mass called the ___
ala
At the superoanterior part of the lateral surface of each ala is the ____ ( a large articular process for articulation with similarly shaped processes on the iliac bones of the pelvis )
articular surface
The ____ projects superiorly from the posterolateral aspect of the first coccygeal segment to join the sacral cornua
coccygeal cornua
The inferior surfaces of the apex of the sacrum has an oval facet for articulation with the ___ &____ (two processes that project inferiorly from the posterolateral aspect of the last sacrl segment to join the coocygeal cornua)
coccyx and the sacral cornua
what is the sacral canal?
continuation of the vertebral canal -contained within the bone and transmits the sacral nerves
The coccyx ____ in size from its base inferiorly to its apex
diminishes
The sacrum is wedged between___, with its broad base directed ___, __, and __ and its apex directed __ and __.
iliac bones of the pelvis obliquely, superiorly, and anteriorly posteriorly, and inferiorly
The superior surface of the base of the sacrum corresponds in size and shape to the _____
inferior surface of the last lumbar segment, with which it articulates to form the lumbosacral junction
Form the coccyx's articulation with the sacrum, it curves ___ &___, often deviating from the midline of the body
inferiorly and anteriorly
The superior portion of the first sacral segment remains distinct and resembles the vertebrae of the _____ region
lumbar
Each of the anterior an posterior walls of the sacral canal is perforated by four pairs of ____ for passage of the sacral nerves and blood vessels
pelvic sacral formaina
Directly behind the bodies of the sacral segments is the ____
sacral canal
At its superior anterior margin, the base of the sacrum has a prominent ridge termed the __ __
sacral promontory
The _____ of the first sacral segment articulate with the inferior articular processes of the last lumbar vertebrae to form the last pair of zyagpophyseal joints
superior articular processes
sacrum What forms the last pair of intervertebral foramina?
the concavities on the upper surface of the pedicles of the first sacral segment and the corresponding concavities on the lower surface of the pedicles of the last lumbar segment
The sacrum is formed by ______
the fusion of the five sacral vertebral segment into a curved, triangular bone
