Lülilülid
Lülilülid, often referred to as vertebrae, are the individual bones that make up the spinal column of most vertebrates. The spinal column, also known as the vertebral column or backbone, serves as a central structural support for the body, protecting the spinal cord and allowing for movement. The number and shape of lülilülid vary significantly across different species, reflecting their specific adaptations and evolutionary history. For instance, mammals typically have a consistent number of cervical (neck), thoracic (chest), and lumbar (lower back) vertebrae, while reptiles and birds exhibit greater variation. Each lülilülid generally possesses a central body, a vertebral arch, and processes that serve as attachment points for muscles and ligaments. The arrangement of these bones allows for a range of motion, from the flexibility of a snake to the upright posture of humans. Disorders affecting lülilülid can lead to pain, mobility issues, and neurological problems.