Vertebral column and sacral curvatures) form during fetal development. The secondary curves develop after birth. The cervical curvature forms as a result of lifting the head and the lumbar curvature forms as a result of walking. The vertebral column surrounds the spinal cord which travels within the spinal canal, formed from a central hole within each vertebra. The spinal cord is part of the central nervous system that supplies nerves and receives information from the peripheral nervous system within the body. The spinal cord consists of grey and white matter and a central cavity, the central canal. Adjacent to each vertebra emerge
Hayden (given name) but down from No. 52 in 2012 and No. 43 in 2011. Hayden (given name) Hayden is a given name in the English language. The name is variant of the given name "Haydn", which is derived from the surname "Haydn" in honour of composer Joseph Haydn (1732–1809). The surname "Haydn" originated as a respelling of the nickname "Heiden", meaning "". The name is derived from the Middle High German "heiden", and from the Old High German "heidano". The form "Haydn" was generally considered a masculine given name up until the mid 20th century. The popularity of "Hayden" has been influenced