Final answer:
The sacral spinal cord cross-section features the median sacral crest and lateral sacral crest formed by the fusion of spinous and transverse processes respectively, as well as the anterior and posterior sacral foramina for sacral spinal nerves exit, among other characteristics.
Step-by-step explanation:
Characteristics of the Sacral Spinal Cord (SC) Cross-section
The sacrum is a triangular-shaped bone that plays a crucial role in the human skeletal structure. It serves as a strong foundation for the weight bearing, superior base, and narrows down to a non-weight bearing, inferior apex. The sacral SC cross-section would reveal characteristics of the bone itself after the fusion of the five sacral vertebrae. This fusion starts post age of 20, creating several distinct features such as the median sacral crest, which is a bumpy ridge on the posterior surface running down the midline formed by the fused spinous processes. The anterior surface showcases four transverse ridges, representing the lines of vertebral fusion. Furthermore, the lateral sacral crest is formed from the fused transverse processes of the sacral vertebrae.
Other identifiable characteristics of the sacral cross-section include the anterior (ventral) and posterior (dorsal) sacral foramina, which allow branches of the sacral spinal nerves to exit the sacrum. The sacral hiatus marks the inferior opening and termination of the sacral canal, and the sacral promontory represents the anterior lip of the base of the sacrum. The sacrococcygeal curve is also a notable feature, forming an anteriorly concave curvature with the coccyx, which itself is derived from the fusion of four small vertebrae.