APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -The sacrum is a single, triangular-shaped bone formed by the fusion of five sacral vertebrae. On the posterior sacrum, the median sacral crest is derived from the fused spinous processes, and the lateral sacral crest results from the fused transverse processes.

Detailed explanation-2: -The sacrum is made of five fused vertebrae configured as an inverted triangular bone that is concave anteriorly and convex posteriorly. Within the sacrum lies the sacral canal, which is a continuation of the vertebral canal.

Detailed explanation-3: -Coccyx is a triangular tailbone, united with sacrum by intervertebral (3 to 5 fused bones) disk. Usually, it is formed by fusion of 4 vertebrae below the sacrum.

Detailed explanation-4: -These five vertebrae are separate in children and young people. They begin to fuse in late adolescence and early adulthood and are usually fully fused by age 30. The sacrum acts as the base of the spinal column, as well as the back “wall” of the pelvis.

Detailed explanation-5: -Five vertebrae are fused together to form the sacrum (part of the pelvis), and four small vertebrae are fused together to form the coccyx (tailbone).