Answer: 5 fused vertebrae
The sacrum is a concave sphenoid bone that sits at the bottom of the spinal column. It looks like an inverted triangle: the widest part (base) is at the top and the pointy end (apex) is at the bottom. The sides of the sacrum connect to the right and left hip ( iliac) bones. The apex is connected to the tailbone ( coccyx ).
The sacrum (plural: sacra or sacrums ) in human anatomy is a large triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1–S5) between ages 18 and 30. The sacrum situates at the upper back part of the pelvic cavity between the two wings of the pelvis. It forms joints with four other bones.
Sacrum (Sacral Region) The sacral region ( sacrum ) is at the bottom of the spine and lies between the fifth segment of the lumbar spine (L5) and the coccyx (tailbone). The sacrum is a triangular-shaped bone and consists of five segments (S1-S5) that are fused together.
The sacrum is a large wedge shaped vertebra at the inferior end of the spine. It forms the solid base of the spinal column where it intersects with the hip bones to form the pelvis. The sacrum is a very strong bone that s...