Bones Of Spine

Vertebrae in the human body are the bones that make up the spine. They are stacked on top of each other and separated by discs that act as shock absorbers. The vertebrae provide support for the head and neck, and also protect the spinal cord.

The spine or backbone consists of 26 small bones or vertebrae. It is also known as the vertebral column.

The vertebral column is a part of the axial skeleton, which comprises the skull, ribs and sternum in addition to the vertebral column. The notochord present in the embryonic stage is replaced by the vertebral column.

The spine forms the main framework of the trunk. It is dorsally placed and attached to the base of the skull.

The spine protects the spinal cord, with each vertebra having a central hollow portion that forms the neural canal through which the cord passes.

Spine or Vertebral Column Anatomy

Structure of Vertebrae

Frequently Asked Questions

Spine or Vertebral Column Anatomy

Our spine consists of twenty-six vertebrae. In the human body, there are 33 vertebrae in total, but the five sacral and four coccygeal vertebrae are fused together, so taken as one each. The upper twenty-four spine bones are separated from each other by an intervertebral disc between them.

The upper twenty-four vertebrae bones are movable and the rest are fused. Vertebrae anatomy of each region is unique and has different structure and functions.

Learn more about vertebrae here!

The spine or the vertebral column is divided into five parts. The bones of the spine are named according to the regions, with the cervical vertebrae labeled as C1, C2, C3, etc., the thoracic as T1, T2, etc., and the lumbar as L1, L2, and so on.

  1. Cervical - 7 vertebrae (C1 to C7):
  • The first vertebra, C1 or Atlas, articulates with the two occipital condyles of the skull, allowing for the maximum movement of the neck. It is responsible for the ‘yes’ movement of the head.
  • The C2 and C1 joints allow the ’no’ movement of the head.

It can bear the weight of the head.

Check out this article to find out How many bones are there in the human neck?

  1. Thoracic: The thoracic region consists of 12 vertebrae (T1 to T12). These vertebrae have limited movement and provide support to the rib cage, protecting the lungs and heart. Additionally, 12 pairs of rib bones articulate with the thoracic vertebrae on the posterior side.

  2. Lumbar

  3. There are five lumbar vertebrae (L1 to L5) that support the weight of the body.

  4. These vertebrae are larger in size and help in carrying heavy objects.

  5. Sacral- The five sacral vertebrae (S1 to S5) are fused together and connect the vertebral column to the hip bones, forming the pelvic girdle.

4. Coccygeal: 1 (Fused Tailbone) - The four bones of the coccyx region fuse together to form a single, fused tailbone.

The vertebral formula is used to calculate the number of vertebrae in each section of the spinal column. The number of cervical vertebrae is 7, thoracic vertebrae is 12, lumbar vertebrae is 5, and sacral vertebrae is 5. The sacrum and coccyx have between 3 to 5 vertebrae each, respectively. This gives a total of 33-35 vertebrae.

The spinal canal, formed by the central portion of each vertebrae bone, encloses the spinal cord and provides protection.

There are various ligaments that aid in the movement and stabilization of vertebrae.

Injury to any of the vertebrae can lead to a range of issues and reduced mobility, such as pain, numbness, tingling, difficulty breathing, quadriplegia, paraplegia, or paralysis.

Structure of Vertebrae

A labelled diagram of the vertebral column or spine is shown below:

Bones of Spine

Frequently Asked Questions

The 26 bones of the spine are called vertebrae.

The 26 bones of the spine are called vertebrae. The first 5 bones of the spine are known as the cervical vertebrae, the next 12 bones are known as the thoracic vertebrae followed by 5 lumbar vertebrae and then one fused sacral and a coccyx at the last.

The 5 Sections of the Spine are:

  1. Cervical Spine
  2. Thoracic Spine
  3. Lumbar Spine
  4. Sacrum
  5. Coccyx

The 5 sections of the spine from the top to bottom are:

  1. Cervical
  2. Thoracic
  3. Lumbar
  4. Sacral
  5. Coccygeal

Cervical

Thoracic

Lumbar

Sacral

Coccygeal

Humans have 33 vertebrae in their spine.

The adult human spine consists of 26 bones, however, there are 33 vertebrae (individual bones) present in the spine of children. Some of the spine bones at the lower part get fused during development.

What are the Four Main Functions of the Spine?

  1. Support the body’s weight
  2. Allow for movement
  3. Protect the spinal cord
  4. Provide attachment points for muscles and ligaments

The 4 main functions of the spine are:

  1. Support the body
  2. Protect the spinal cord
  3. Enable flexibility and movement
  4. Help with balance and posture

It shields the spinal cord.

It supports the head.

It provides a point of attachment to the ribs and muscles at the back.

It provides structural support and aids in locomotion and movement.

The first two bones of the spine are the Cervical Vertebrae.

The first bone of the spine is Atlas and the second bone is Axis. They are the first two cervical vertebrae.

The type of joint present between the bones of the spine is a synovial joint.

The adjacent bones of the spine are joined together by cartilaginous joints. This type of joint allows limited movement of bones.

The joint between the atlas and axis is called the atlantoaxial joint.

The joint between the atlas and axis is called a pivot joint.

The Spinal Cord and Vertebral Column

The spinal cord is a bundle of nerves that runs from the base of the brain down the center of the back. It is responsible for carrying messages between the brain and the rest of the body. The vertebral column, also known as the spine, is a series of bones that run along the back and protect the spinal cord. The vertebral column provides support for the body and allows for movement.

The vertebral column, a bony, segmented structure that supports the head and thorax, is one of the main components of the central nervous system, which also includes the spinal cord. The vertebral column holds the spinal cord, protected by the vertebral column.

Caudal Vertebrae

Caudal vertebrae are the vertebrae located in the tailbone region of the vertebral column. They are the most caudal of the vertebrae and are also known as the coccygeal vertebrae.

Spinal Cord Vertebrae

Spinal cord vertebrae are the vertebrae that form the vertebral column and protect the spinal cord. They are divided into five regions: cervical, thoracic, lumbar, sacral, and coccygeal.

Vertebrates have caudal vertebrae that form the tail. The number of caudal vertebrae can range from a few to fifty, depending on the size of the tail. In humans and other tailless vertebrates, these vertebrae are known as coccygeal vertebrae and usually range from three to five, which are fused together to form the coccyx.

The spinal canal consists of 33 stacked vertebrae, which are small bones that make up the spinal cord. The vertebral column is a tunnel that houses and protects the nerves and spinal cord from harm. To allow for a variety of motions, most vertebrae are able to move. The sacrum and coccyx are the lowest vertebrae and are fused, so they are unable to move.

What are the bones of the spine that are attached to ribs?

Thoracic vertebrae are connected to ribs.

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