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Spinal Column | Spine Bones

The Spinal Column

Also known as the backbone or vertebral column, consists of a long chain of 33 bones each individually known as a vertebrae.

The main functions of the vertebral bones are for

  • structure
  • and protection of the spinal cord.

The spine is separated into 4 curves;

  • the cervical curve
  • thoracic curve
  • lumbar curve
  • sacral or pelvic curve

Below are detailed diagrams and information regarding the spine bones. Learn the names of the spine bones and spine anatomy.

Vertebral Bones

List of all Vertebral Bones

 

  • cervical vertebrae (7)
  • thoracic vertebrae (12)
  • lumbar vertebrae (5)
  • sacral vertebrae (1)
  • coccygeal vertebrae (1)

Cervical Vertebrae

Cervical Vertebra

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  • The cervical vertebrae is the first set of vertebral bones of the spine, located inferior to the skull.
  • The cervical vertebrae consists of 7 vertebral bones, denoted as C1, C2, C3, C4, C5, C6, and C7.
  • These bones “stack” up each other, starting with C1 and ending with C7.
  • The primary function of the cervical vertebrae is protection of the spinal cord and support of the body.
  • These vertebrae can flex and extend to allow for movement.

Furthermore, the cervical vertebrae are generally smaller than the other vertebrae.

Small anatomical differences do exist between each of the cervical vertebra, but for the most part they are similar. C1 is unique in that it contains the joint between the spine and the skull, since it is the first bone of the vertebral column.

Thoracic Vertebrae

Thoracic Vertebra

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  • The thoracic vertebrae is the set of vertebrates following the cervical vertebrae and is the middle segment of the spine.
  • The thoracic vertebrae consists of 12 vertebral bones, denoted as T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, and T12, these bones increase in size and width from T1 to T12.

Furthermore, the thoracic vertebrae are of intermediate size, larger than the cervical vertebrae and smaller than the lumbar vertebrae.

The thoracic vertebrae houses the spinal cord and protects the spinal cord.  During movement, the thoracic vertebrae can flex and move.

Lumbar Vertebrae

Lumbar Vertebra

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  • The lumbar vertebrae is the third curve of the spine and follows the thoracic vertebrae.
  • The lumbar vertebrae consists of 5 vertebral bones, denoted as L1, L2, L3, L4, and L5.
  • These are the largest vertebral bones and each individual bone increases in size from L1 through L5, like the cervical and thoracic vertebrae.

The function of the lumbar vertebrae is the protection of the spinal cord. Additionally, the lumbar vertebrae allows for much of human body motion and supports much of the human body’s weight.

Sacral Vertebrae

Sacrum

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  • The sacral vertebrae is the fourth and final curve of the vertebral column, located at the base of the spine following the lumbar vertebrae.
  • The sacral vertebrae consists of one bone, known as the sacrum.
  • Initially, in children, the sacrum is made up of 5 separate bones.
  • However, as the body ages, the 5 bones fuse to collectively form the sacrum.
  • For this reason, the sacrum is divided into 5 regions, the S1, S2, S3, S4, and S5.
  • The sacrum is a triangularly shaped bone located between the hip bones.

The function of the sacrum is protection and support of the body. Interestingly, the 5 separate bones of the sacrum begin to fuse during the late teen years and are usually completely fused by the age of 25 or 26.

Coccygeal Vertebrae

Coccyx

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  • The final portion of the spine or vertebral column is the coccyx.
  • The coccyx, also known as the tailbone, is composed of 3 or 5 bones fused together.
  • Although for the most part the bones are fused together to form a single coccyx, and the coccyx is referred to as one bone in anatomical texts, in some adults the coccyx consists of separate, unfused bones. However, this is most likely not the norm.

Since human’s do not contain a tail, the coccyx or tailbone is sometimes referred to as a vestigial structure. However the coccyx has many functions in the human body,  such as providing protection, support while sitting, and serving as the location of many attachment sites for ligaments and muscles.

A overview of the Spinal Column.

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Test Your Knowledge

How Many Bones in the Human Body?

An adult has a total of 206 bones in their skeleton

How many Bones in a Child's Body?

A newborn baby has 270 bones in the skeletal system. Most of their skeleton is made up of cartilage which forms bone as it hardens over time. The bones in a child's skeleton fuse together as they grow, reducing the number, up until about 25 years old.

What is The Strongest Bone in the Human Body?

The femur or thigh bone is the strongest bone in the body. It is situated between the pelvis and the knee. It is also the longest bone in the body and is fully one quarter of your bodies' height.

What is the Weakest Bone in The Body?

The weakest bones in your body are the tiny bones inside your ear that enable you to hear. On the other hand; the most commonly fractured bone is the clavicle.

What is the Hardest Bone in the Body?

The hardest bone in the body is the petrous portion of the temporal bone. The temporal bones are found at the sides and base of the skull and the petrous portion is specifically the part at the base of the skull that contains the organs for hearing.

Where are the Smallest bones in Your Body Located?

The smallest bone in the body is called the stapes. It is a stirrup shaped bone found inside the ear drum that transmits vibrations enabling us to hear.

How many Bones are in the Leg?

A human leg contains 30 bones. There are 26 bones that make up the foot, and the four major bones of the leg, which are the thigh bone (femur), the shin bone (tibia), the calf bone (fibula) and the knee cap (patella)