QUIZ II Flashcards
what comprises the pelvis?
2 pelvic bones
1 sacrum
1 coccyx
what is the function of the pelvis?
contains and protects the pelvic organs, aid in locomotion via force transfer
what is unique about the sacrum?
5 vertebrae fused
recognized by its shape
base is narrower and length longer, greater curvature in males whereas in females, based is wider and length shorter with lesser curvature
what does the base of the sacrum articulate with?
L-5 vertebra
what does the apex of the sacrum articulate with?
coccyx
what is the coccyx?
4 vertebrae fused into 2 or 3 segments, aka the tail bone
- formed by fusion of the vertebral bodies
- last area in the body to complete ossification
Transverse Ridges (Lines) (4)
- allow passage of the ventral rami S-1 through S-4
- holes at anterolateral sacral canal
Anterior Sacral Foramina (4 pair)
- concave side to side and superior to inferior
anterior surface of the sacrum
- anterior superior edge of S-1 vertebra
- projects in anteroinferior direction in body
Sacral Promontory
(ala means wing)
- expansions from the base, laterally
- the fused transverse processes of S-1 vertebrae
Sacral Alae
- unfused superior articular processes of S-1
- visible from anterior side, are part of the posterior aspect
- articular surface is posterior
Superior Articular Processes
-no true features from anterior
anterior surface of coccyx
-spinal canal of the sacrum for passage of cauda equina
Sacral Canal
- midline projection from sacrum
- the fused spinous processes of S-1 through S-4
Median Sacral Crest
- the inferior opening of the sacral canal
- formed by the lamina and spinous processes from S-5 that do not fuse
- for passage of meninges and spinal nerves. Area of attachment for filum
terminale
Sacral Hiatus
- small projections at the lateral margins of the sacral hiatus
- formed by ligamentous attachment
Sacral Cornu
- for passage of dorsal rami S-1 through S-4
Posterior Sacral Foramina (4 pair)
- projection at the medial edge of the dorsal sacral foramina, and lateral to
the median sacral crest
39 - formed by fusion of the superior and inferior articular processes
Intermediate Sacral Crest
- depressed area between median and intermediate sacral crests
- formed by fusion of the vertebral laminae S-1 through S-4
Sacral Groove
- projection lateral to the dorsal sacral foramina
- formed by fusion of the transverse processes
Lateral Sacral Crest
- superior articular processes of Co-1 vertebra
- articulate with sacral cornu via ligamentous attachment
Coccygeal Cornu
- anterior part of the lateral surface, articulates with the pelvic bone
- part of the sacroiliac joint, a synovial joint, planar, functional diarthrosis
Auricular Surface
- all present at birth
- one in each vertebral body, one in each of the lamina (vertebral arches forming the
sacral canal), one in each segment of the lateral masses (costal elements)
Primary Centers of Ossification