Most people have heard of the term “vertebrae.” But do you know exactly what that word is referring to? Vertebrae are the bones found inside the vertebral column. For humans, the vertebrae are a sequence of 33 bones that run from the base of the skull down to the coccyx.

The average person is born with 33 vertebrae. These bones are linked to each other through flexible joints known as facets. However, by the time a person reaches adulthood, they will likely only have 24 vertebrae because certain vertebrae at the bottom of the spine fuse together during development.

Some people have an additional vertebra, called a transitional body. These vertebrae are typically located at the sixth level of the lumbar region.

The Vertebral Column: The Basics

Before diving into the different types of vertebrae, it’s essential to have a firm grasp of the structure and function of these bones. The vertebral column starts where the skull ends and continues down to the lower back area. The vertebral column is categorized into five sections:

• Cervical
• Thoracic
• Lumbar
• Sacrum
• Coccyx

Vertebrae are irregularly shaped. As a result, this structure of bones forms what looks like an S-shape in the spinal cord. An intervertebral disc is located between each vertebra, which helps absorb shock and defend the vertebrae from outside forces. These discs are integral to the structure of the vertebrae.

The body of vertebrae is divided into the centrum and the posterior vertebral arch, also known as the neural arch. The shape of vertebrae depends on which area of the body they’re found in, as well as what species they are.

Vertebrae bodies are made up of a spongy bone material called cancellous bone. These bodies are covered in cortical bone, a denser, harder bone designed for protection. Vertebrae help protect the spinal cord and reduce the risk of harm from daily activity. However, different issues can affect the vertebrae, including abnormal bending of the spine like scoliosis.

It is also possible to get disc herniations, which occur when intervertebral discs in your spine stick out and place painful pressure on the spinal column. People can also be at risk of degenerative disc disease, which is when the body’s discs start to disintegrate, which can be extremely painful.

Luckily, proper posture when sitting and standing, as well as sleeping correctly, can help protect your vertebrae, so you’re less at risk of those problems. The type of chair you sit in can also affect it. Learn more about the different types of vertebrae with all33 in our informative guide!

Near the bottom of the skull, the cervical vertebrae begin the vertebral column. Every person has seven of these bones, and they are identified by the values C1 through C7. Two notable bones in this sequence are C1 and C2.

C1 is known as the atlas. This name refers to how this bone surrounds the skull. The atlas does not have a body and instead holds a circular structure that goes around the skull. The atlas is made up of two connected lateral masses.

C2 is known as the axis because it helps rotate the atlas in either direction. It resembles a tooth and projects upward. Both the C1 and C2 bones have distinct shapes that are unique from the others. They play a pivotal role in supporting the skull.

These vertebrae are responsible for allowing our necks to have a full range of motion. Interestingly enough, giraffes have the same number of cervical vertebrae as humans and can move their necks around in the same fashion.

The thoracic vertebrae refer to the next twelve vertebrae in line. These bones move down the body, connecting to the ribs. They help defend the chest cavity, which contains the heart and lungs. In comparison, the thoracic vertebrae are significantly larger in size than the cervical vertebrae.

There are 12 thoracic vertebral bones, and they’re labeled T1 – T12. Usually, when the thoracic region is mentioned, it is about a person’s rib cage. The rib cage is located in the thoracic region of the body and interacts with the thoracic vertebrae.

To articulate with the ribs, the thoracic vertebrae undergo a minor modification. This modification produces demifacets. A demifacet is half of a facet and allows those vertebrae to articulate with the ribs and costal cartilage. The thoracic vertebrae contain both superior and inferior demifacets. Each rib in the body corresponds to a vertebra, as well as a vertebra above it.

Next up are the lumbar vertebrae, the next five vertebrae in the vertebral column. These bones are known by the values L1 – L5. These bones are the largest out of the five groups of vertebrae. Compared to the other vertebrae, the lumbar vertebrae have massive bodies.

Most of the lumbar vertebrae are similar structurally. However, some exceptions exist. The major weight-bearing structure in the lumbar section is the vertebral body, which is positioned in front. The five bones in this sequence progressively increase in size as they run down the lower back.

A notable feature of the lumbar vertebrae is its bony vertebral arch. This arch contains an open central space. It is made up of five components. The main part of the arch is the laminae, which decrease in size from L1-L5.

This arch also contains the spinous process, a bony protrusion that sticks out backward and downward. You can feel this bone while touching your lower back. It acts as an attachment for different muscles in the spine.

One of the main functions of the lumbar vertebrae is to help create a natural curve in the spine. They also support the most weight from the body out of any other vertebrae species. These bones have a tremendous ability to move around, and they allow for the flex, bend, and extension of the spine.

The next two vertebrae types are the sacrum and the coccyx. Generally, the sacrum and coccyx are viewed as one section called the sacrococcygeal region.

The sacrum is made up of five bones that come together to build a single bone. Meanwhile, the coccyx is composed of three to five bones that also come together to form a single structure. For females, their sacrum is short and broad, while for males, it is long and slender. The sacral and coccygeal vertebrae do not have intervertebral discs.

There are two final sections of vertebrae in the sacrococcygeal region. First, there are five bones known as the fused sacrum. After that, there are three to five last bones that connect to create the coccyx or tailbone. And thus, the vertebral column is formed.

The vertebral column is one of the foundational structures of the human body. Housing the spinal cord, this sequence of bones extends from the base of your skull all the way down to the coccyx. Without it, our torsos would basically be lumps of flesh with no form.

From the natural curvature of our spines to the S-shape of our backs, our vertebrae work every day to uphold our bodies and keep us moving smoothly. All five sections of the vertebral column; the cervical, thoracic, lumbar, sacrum, and coccyx; all play important roles in supporting you.

It is crucial to protect your vertebral column at all costs. Damage to the structure can be very dangerous and could lead to permanent consequences. You should be especially cautious when exercising or lifting weights, where you are actively placing pressure onto that area of your body.

You can also support your vertebral column by sitting, standing, and sleeping with proper posture. These three acts describe a majority of the positions that you’ll find yourself in on a regular day. What most people don’t realize, though, is that when you’re in these positions, your back is working laboriously to hold you up.

For that reason, you should be courteous to your body and keep your back high and straight in all these situations. When sitting, keep your chest high and place your legs shoulder width apart. If reading from a book or using a device, make sure that you’re not looking downward to see your target. Doing so will put strain on your neck and tighten the muscles in that area.

At all33, we aim to provide people with freedom from their back, neck, and spine pains. Our evidence-based, intuitive chairs are designed to promote good posture, flexibility, blood flow, and oxygen flow.

Our innovative Sit In Motion® technology allows for full range of movement of your pelvis and back when sitting, a feature that no other brand in the world has. Regular chairs force your pelvis and back to be stiff and motionless. Our chairs offer instant relief and ensure a slouch-free comfortable experience.

Sources:

• Vertebrae - Definition, Parts, Types, and Function | Biology Dictionary
• Vertebral Column (Spine) | Biology Dictionary
• Lumbar Vertebrae | Spine Health