Spine
Columna vertebralis
// Structure & location
According to OpenStax, the adult spine has 24 vertebrae: 7 cervical, 12 thoracic and 5 lumbar. Below them come the sacrum, made of five fused vertebrae, and the coccyx. Between the vertebral bodies lie the discs, made of a tough fibrous ring and a soft core. The spine has four curves: forward in the neck and lower back, backward in the chest and at the sacrum.
// Function
It carries the head and trunk and passes the load on to the pelvis. That's why the vertebral bodies get larger and thicker towards the bottom. The spinal cord lies protected in the spinal canal. According to OpenStax the curves increase strength, flexibility and shock absorption. The lumbar spine bends and straightens well but barely rotates. Most rotation happens in the thoracic spine.
// For training & sport
- When lifting heavy, brace the trunk so the spine keeps its natural shape.
- Rotation is better driven from the thoracic spine and hips than from the lower back, which is barely built for it.
- Strength training strengthens the muscles that support the spine, above all the erector spinae and the abs.
// Good to know
Almost all mammals have seven neck vertebrae, including the giraffe; according to OpenStax its are just much larger. In a herniated disc, the soft core pushes out through a weakened fibrous ring.
// Sources
- LehrbuchOpenStax – Anatomy and Physiology, 7.3 The Vertebral Column ↗
- LehrbuchOpenStax – Anatomy and Physiology 2e, Chapter 7 Review: The Axial Skeleton ↗