Understanding Spine Anatomy
Spine anatomy is the foundation of understanding back and neck pain. The human spine is a remarkable structure made up of 33 vertebrae, intervertebral discs, nerves, muscles, and ligaments working together to support your body, protect your spinal cord, and allow movement. Dr. Alok Sharan, MD, MHCDS — board-certified orthopedic spine surgeon and pioneer of awake spinal fusion — has spent over 20 years treating conditions of every region of the spine at his Edison, NJ practice serving patients throughout New Jersey and NYC.
Vertebrae
The Four Regions of the Spine
Cervical spine — 7 vertebrae (C1–C7) supporting the head and neck
Thoracic spine — 12 vertebrae (T1–T12) attached to the rib cage
Lumbar spine — 5 vertebrae (L1–L5) bearing most of your body’s weight
Sacral spine & coccyx — fused bones forming the base of the spine
What Does the Spine Do?
Your spine serves three critical functions: it supports your body’s weight and keeps you upright, it protects the spinal cord and nerve roots running through the vertebral canal, and it enables the flexible movement that lets you bend, twist, and turn. Every vertebra is connected by facet joints and separated by intervertebral discs — shock-absorbing cushions made of a tough outer layer (annulus fibrosus) and a soft gel-like center (nucleus pulposus).
Understanding spine anatomy helps you make informed decisions about treatment. Dr. Sharan’s philosophy is to fully educate patients about their spinal condition before recommending any intervention. Explore each region below to learn more.
Key Structures in Spine Anatomy
Vertebrae are the individual bones that stack to form the spinal column. Each has a cylindrical body in front, a spinous process projecting to the back, and transverse processes on the sides for muscle attachment. The hollow center forms the spinal canal that houses the cord.
Intervertebral discs sit between each pair of vertebrae. When a disc’s outer layer tears, the inner material can bulge or herniate and press on nearby nerves, causing radiating pain down the arm (cervical) or leg (lumbar) such as sciatica or a pinched nerve.
The spinal cord runs through the central canal from the brainstem to approximately the L1–L2 level, where it branches into the cauda equina supplying the lower body. Protecting this neural tissue is the primary goal of all spine surgery.
Facet joints are small paired joints at the back of each vertebral level guiding movement and preventing excessive rotation. Arthritis in these joints is a common source of axial back pain. Ligaments and muscles including the anterior and posterior longitudinal ligaments provide critical stability throughout all four spinal regions.
Years Experience
When Spine Anatomy Becomes a Problem
Dr. Alok Sharan, MD, MHCDS is a Castle Connolly Top Doctor and NY Magazine Best Doctor with 20+ years of experience treating conditions affecting every region of the spine. Fellowship-trained at NYU Hospital for Joint Diseases and Deputy Editor of Clinical Spine Surgery, Dr. Sharan has published over 100 peer-reviewed studies on spinal conditions and surgical outcomes.
His pioneering awake spinal fusion technique performs spine surgery under regional anesthesia rather than general anesthesia — resulting in faster recovery, same-day discharge, and fewer complications. Located at 35-37 Progress St., Suite B5, Edison, NJ 08820, he serves patients throughout New Jersey and NYC.
Board-certified orthopedic spine surgeon
201 five-star Google reviews
Castle Connolly Top Doctor & NY Magazine Best Doctor
Frequently Asked Questions About Spine Anatomy
How many bones are in the spine?
The adult spine contains 26 bones: 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 1 sacrum (5 fused), and 1 coccyx (3–5 fused). Children begin with 33 separate vertebrae before the lower ones fuse in early adulthood.
What are intervertebral discs?
Intervertebral discs are fibrocartilaginous pads between each pair of vertebrae that act as shock absorbers. When a disc degenerates or herniates, it can compress nearby nerves causing conditions like sciatica or a pinched nerve.
Which region of the spine is most commonly injured?
The lumbar spine (lower back) is most frequently affected because it bears the greatest mechanical load. The cervical spine (neck) is the second most common region, particularly from disc herniation and stenosis.
When should I see a spine specialist?
See a specialist if you have persistent back or neck pain lasting more than 4–6 weeks, pain radiating into the arms or legs, weakness or numbness, or difficulty walking. Dr. Alok Sharan at The Spine and Performance Institute in Edison, NJ is available at (732) 898-3950.
