The pelvic bones include the: Sacrum (the large triangular bone at … The top of the first (uppermost) sacral The sacrum is actually made up of five vertebrae that fuse together between age 18 to 30. Learn more about the pelvis in this article.

Pelvis definition, the basinlike cavity in the lower part of the trunk of many vertebrates, formed in humans by the innominate bones, sacrum, etc. It also contains many passages for the spinal nerves that exit the spinal cord and spread through the pelvis … The sacrum and coccyx form the inferior end of the vertebral column where it meets the hip bones to form the pelvis. The pelvis is a ring of bones located at the lower end of the trunk—between the spine and the legs.

Gross anatomy.
Located just above the coccyx and wedged between the right and left iliac bones (hip bones), the sacrum forms the back wall of the pelvis. See more. Pelvis, in human anatomy, basin-shaped complex of bones that connects the trunk and the legs, supports and balances the trunk, and contains and supports the intestines, the urinary bladder, and the internal sex organs. Sacrum definition, a bone resulting from the fusion of two or more vertebrae between the lumbar and the coccygeal regions, in humans being composed usually of five fused vertebrae and forming the posterior wall of the pelvis. It consists of the last four or five vertebrae that by adulthood, fuse together to form a single bone. See more. The coccyx, or "tail bone," is located under the sacrum, and is made of three to five vertebrae that naturally fused together. Sacrum, wedge-shaped triangular bone at the base of the vertebral column, above the caudal (tail) vertebrae, or coccyx, that articulates (connects) with the pelvic girdle. The sacrum is a large triangular-shaped bone found at the base of the spinal column. The bony pelvis is formed by the sacrum and coccyx and a pair of hip bones (os coxae or innominate bones), comprising the ischium, pubis and ilium and are part of the appendicular skeleton.. Its primary function is the transmission of forces from the axial skeleton to the lower limbs as well as supporting the pelvic viscera.. In humans it is usually composed of five vertebrae, which fuse in early adulthood. The triangular sacrum forms joints between the lumbar vertebrae and the hip bones.

There is a joint between the sacrum and the ilia, called the sacroiliac joint, or SI joint.