About the spine
The spine, or vertebral column, forms the central supporting structure of the body. It protects the spinal cord, allows upright posture, and provides flexibility for movement. The spine is made up of 33 vertebrae, stacked one on top of the other, separated by discs that act as shock absorbers.
Running through the centre of the vertebrae is the spinal canal, which contains the spinal cord and its protective coverings. The spinal cord is a continuation of the brainstem and acts as the main communication highway between the brain and the rest of the body. Nerves branch off the cord through small openings in the vertebrae, carrying signals to and from muscles, skin, and organs.
Just like the brain, the spinal cord depends on a constant blood supply. Interruption of this supply, due to narrowing, blockage, or bleeding in the spinal vessels, can cause loss of function, weakness, or paralysis.
## Structure of the Spine
description: An overview of the spine and spinal cord, including vertebrae, spinal nerves, coverings, and blood supply. tags: Essential knowledge keywords: “spine anatomy, spinal cord, vertebrae, spinal nerves, spinal blood supply, London” about: “The spine supports the body, protects the spinal cord, and allows motion. The spinal cord relays signals between brain and body; its function depends on a fine vascular supply, and injury or disease can lead to serious deficits.” mainEntity: “https://en.wikipedia.org/wiki/Vertebral_column” sameAs: “https://en.wikipedia.org/wiki/Spinal_cord” —
- Cervical spine – The top 7 vertebrae (neck region). Supports the head and allows movement such as turning and nodding.
- Thoracic spine – The next 12 vertebrae (upper and mid-back). These connect to the ribs and help protect the chest organs.
- Lumbar spine – 5 vertebrae in the lower back. These bear much of the body’s weight and allow bending and twisting.
- Sacrum and coccyx – The base of the spine, fused bones that connect to the pelvis.
Spinal Cord and Nerves
The spinal cord is divided into regions that correspond with the spine: cervical, thoracic, lumbar, and sacral. Each region gives rise to pairs of spinal nerves, which exit the spine through small gaps between vertebrae. These nerves carry:
- Motor signals – from the brain to the muscles (movement).
- Sensory signals – from the skin and body back to the brain (touch, pain, temperature).
- Autonomic signals – to organs, controlling functions such as blood pressure, bladder, and bowel control.
Coverings and Fluid
- Meninges – As in the brain, three protective layers (dura, arachnoid, pia mater) surround the spinal cord.
- Subarachnoid space – The space between these layers where cerebrospinal fluid (CSF) circulates.
- CSF – Cushions the spinal cord, provides nutrients, and helps remove waste products.
Blood Supply to the Spine
The spinal cord is supplied by a network of arteries:
- Anterior spinal artery – Runs along the front of the cord, supplying the majority of the spinal cord tissue.
- Posterior spinal arteries – Run along the back of the cord.
- Radicular and segmental arteries – Branches from larger vessels (such as the aorta) that reinforce the spinal circulation at different levels.
Because the spinal cord relies on this delicate blood supply, any blockage or bleed can cause serious neurological problems, such as weakness, numbness, or loss of bladder and bowel control.