Flashcards
Chapter 9 sacrum
Cards in this deck (12)
- 1Anterior perspective of the sacrum-The bodies of the original five segments fuse into a single bone in the adult.
-The sacrum is shovel-shaped, with the apex pointed inferiorly and anteriorly. -Four sets of pelvic (anterior) sacral foramina (similar to intervertebral foramina in more superior sections of the spine) transmit nerves and blood vessels. - 2sacrum-anterior view
- 3Anterior perspective of the sacrum Cont.-The alae, or wings, of the sacrum are large masses of bone lateral to the first sacral segment.
- The two superior articular processes of the sacrum form zygapophyseal joints with the inferior articular processes of the fifth lumbar vertebrae. - 4Lateral perspectiveFig. 9-5 clearly illustrates the dominant convex curve (posterior perspective) of the sacrum and forward projection of the coccyx.
-These curves determine how the central ray must be angled differently for AP radiographic projections of the sacrum or coccyx.
-The anterior ridge of the body of the first sacral segment helps form the posterior wall of the inlet of the true pelvis and is termed the promontory of the sacrum; it is best demonstrated from a lateral perspective - 5sacrum and coccyx-lateral view
- 6Lateral perspective Cont.-Posterior to the body of the first sacral segment is the opening to the sacral canal, which is a continuation of the vertebral canal and contains certain sacral nerves.
-The median sacral crest is formed by fused spinous processes of the sacral vertebrae. - 7Lateral perspective Cont.-The sacrum articulates with the ilium of the pelvis at the auricular surface (marked A in Figs. 9-5 and 9-6) to form the sacroiliac joint.
-The auricular surface is so named because of its resemblance in shape to the auricle of the ear. - 8Lateral perspective Cont.-The sacral horns (cornua) (marked D in Figs. 9-5 and 9-6) are small tubercles that represent the inferior articular processes projecting inferiorly from each side of the fifth sacral segment. -They project inferiorly and posteriorly to articulate with the corresponding horns (cornua) of the coccyx
- 9Posterior Sacrum-Clearly seen is the large, wedge-shaped auricular surface (A), which articulates with a similar surface on the ilium to form the sacroiliac joint.
-Each sacroiliac joint opens obliquely posteriorly at an angle of 30°. - 10Posterior Sacrum-The articulating facets of the superior articular processes (B) also open to the rear and are shown on this photograph. There are eight posterior sacral foramina (C), four on each side, corresponding to the same number of anterior sacral foramina."
- 11posterior sacrum
- 12Posterior Sacrum Cont.-The sacral horns (cornua; D) are seen as small bony projections at the very inferoposterior aspect of the sacrum. -Remnants of the enclosed sacral canal (E) also can be seen. (Deteriorating bone leaves the canal partially open on this bone specimen.)
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- Flashcards on Chapter 9 sacrum, created by Anthony Torres on 27/02/2016.
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- Anthony Torres
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