coccyx
/ˈkɒksɪks
/noun (plural coccyges /ˈkɒksɪdʒiːz/ or coccyxes)
A small triangular bone at the base of the spinal column in humans and some apes, formed of fused vestigial vertebrae.The sacrum itself represents 5 fused bones, and the coccyx another vestigial 2-3 or more - the remains of the ancestral tail....
- The spinal column is composed of seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae, the bony sacrum, and the coccyx.
- Many of my patients have pressure ulcers on the coccyx or sacrum.
Derivatives
coccygeal
- The usual grouping formula of 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal vertebrae is found in only about 20% of individuals studied.
- The lumbosacral plexus is formed by the union of the anterior primary divisions of the lumbar, sacral, and coccygeal nerves.
- The fifth sacral and the coccygeal nerves (when present) are located within the dural cavity.
Origin
Late 16th century: via Latin from Greek kokkux 'cuckoo' (because the shape of the human bone resembles the cuckoo's bill).
Your coccyx is the small triangular bone at the base of your spine. The name comes via Latin from Greek kokkux ‘cuckoo’, because the shape of this bone looks like a cuckoo's beak.