Spinal column

Your backbone is a tall stack of bones.

It is made of many small bones. These bones protect the nerves inside you.

Small pads sit between the bones. These pads help the bones move. The backbone also has curves. These curves help you stay upright. They even help your body handle weight. Many different animals have a backbone.

It is a very important part of your body.

Your spine is a tall stack of bones.

We also call it the spinal column. It is a key part of the skeleton in many animals. About 50,000 species have a spinal column.

The spine is made of small bones called vertebrae. These bones form a tunnel. This tunnel protects the spinal cord inside. Small pads called intervertebral discs sit between the bones. They help the bones move.

In humans, there are usually 33 vertebrae. They are split into different parts. The top part is the cervical spine in your neck. It has 7 vertebrae. The middle part is the thoracic spine in your chest. It has 12 vertebrae. The bottom part is the lumbar spine in your lower back. It has 5 vertebrae. The last parts are the sacrum and the coccyx, or tailbone. In adults, these lower bones are fused together.

The spine is not straight. It has curves that help you stand up. These curves help your body absorb shock. They also make your spine strong. When you carry more weight, the curves get deeper. Then they spring back when the weight is gone.

The spinal column is a very important part of the body. You might know it by other names like the spine or the backbone. It is a part of the axial skeleton in vertebrate animals.

This column of bones is what makes a vertebrate a vertebrate. There are about 50,000 different species of animals that have a spinal column.

It acts as a strong support for the body. It also works to keep the body safe.

This column is made of many small bones called vertebrae. These bones are stacked on top of each other in a line.

Between these bones are soft pads called intervertebral discs. These discs sit in joints to help the bones move. The bones also form a hollow tunnel called the spinal canal. This canal is very important because it protects the spinal cord inside.

Small holes allow spinal nerves to exit the canal to reach the rest of the body.

Scientists have studied the human spine more than almost any other. The way human bones are built is very similar to birds, reptiles, and other mammals.

The spine is divided into different regions based on where they are. The top part is the cervical spine in the neck. The middle is the thoracic spine in the chest. The bottom part is the lumbar spine in the lower back. The very bottom includes the sacrum and the coccyx, which is the tailbone.

A human spine usually has 33 vertebrae in total.

There are 7 cervical vertebrae in the neck region. The thoracic region has 12 vertebrae. The lumbar region has 5 vertebrae. In adults, the lower 9 bones are fused together. This means the 5 sacrum bones and 4 coccyx bones join into one solid piece. Most people have between 32 and 35 vertebrae in total. About 10% of people have a different number of bones in their spine.

The spine is not a straight line like a pole. It has several natural curves that help us stand upright.

These curves help the spine stay strong and flexible. They also help the body absorb shock when we move. When you carry a heavy load, these curves can become deeper. Once the weight is gone, they spring back to their normal shape. The curves in the neck and lower back develop after a baby is born. The neck curve forms when an infant can hold up its head. The lower back curve forms when a child begins to walk.

The spinal column, often called the spine or backbone, is a vital part of the axial skeleton. It is the defining characteristic of all vertebrate animals.

This segmented column of bones protects the spinal cord, which carries messages through the body. There are approximately 50,000 different species of animals that possess a vertebral column. While the shape of the vertebral body varies between species, the human spine is one of the most studied examples. This is because human vertebrae are quite typical of those found in birds, reptiles, and other mammals.

To understand how the spine works, we must look at the individual vertebrae. A typical vertebra consists of two main parts. The first is the vertebral body, or centrum, located at the front. This part withstands the axial structural load, which is the weight pressing down on the spine.

The second part is the vertebral arch, also known as the neural arch. This part is located at the back and provides attachment points for ribs and core muscles. Together, these structures create the vertebral foramen. When these openings align, they form the spinal canal. This hollow cavity encloses and protects the delicate spinal cord.

The spinal column is organized into several distinct regions. These regions correspond to different parts of the body. The cervical spine is located in the neck and contains seven vertebrae. The thoracic spine is in the chest or upper back and has twelve vertebrae. The lumbar spine is in the lower back and contains five vertebrae.

Below these are the sacrum and the coccyx, or tailbone. In a typical human, the sacrum consists of five fused vertebrae. The coccyx consists of four fused vertebrae. While the upper vertebrae are independent bones, the lower nine are fused in adults. Most humans have between 32 and 35 total vertebrae. However, about 10% of people have variations in their vertebral count.

Spinal nerves must travel from the spinal cord to the rest of the body. This happens through small holes called intervertebral foramina. These openings are located underneath the pedicles of the vertebrae. The nerves exit the spinal canal through these gaps to innervate different body segments.

As a person grows, the vertebral column actually outgrows the spinal cord. By the time a person reaches adulthood, the spinal cord often ends near the upper lumbar spine. The lower end of the spinal canal is then filled by a bundle of nerves. This bundle is called the cauda equina, which means "horse's tail" in Latin.

The spine is not a straight rod; it has several natural curves. These curves are a result of human bipedal evolution. They increase the strength and flexibility of the column. They also help the body absorb shock while standing upright. Some curves are called primary curves because they are present in a fetus. These include the thoracic and sacral curves. Other curves are called secondary or compensatory curves because they develop after birth.

The cervical curve forms when an infant holds its head up. The lumbar curve forms when a child begins to walk.

Clinical medicine uses the spine as a map for many procedures. Doctors look at features like the spinous process, which is a bony projection on the back of the vertebrae. These processes can be felt through the skin and serve as surface landmarks. They help guide procedures such as lumbar punctures or spinal anesthesia.

However, the spine can also face health challenges. Various diseases can affect the bony vertebrae or the intervertebral discs. Examples include scoliosis, kyphosis, and ankylosing spondylitis. Spina bifida is noted as the most common birth defect affecting the spinal column.

Finally, the spine is held together by many different ligaments. These are tough tissues that extend along the length of the column. Some, like the anterior and posterior longitudinal ligaments, run along the front and back of the vertebral bodies. Others, like the ligamentum flavum, are located deep within the structure. These ligaments, along with the transverse and spinous processes, provide essential attachment sites for back muscles. This complex system of bone, nerve, and tissue allows vertebrates to move and stay upright.