Human Back Diagram: Structure, Parts & Functions

Hello Kids, we are quite sure that whenever you look at yourself in the mirror, you would have hundreds of questions about your body. As to what our body is made up of? How many parts or organs are there, and what function do they perform? Our body is made of many smaller structures like systems, cells, tissues, and organs.

All the organs in our body are made up of different types of tissues, which when put together perform special functions for us. Like we have skin that protects and covers us, then we have muscles that help us to move around, and many more.

But today, let us focus our learning on that part of our body that supports our weight and plays an essential role in protecting the important organs and the nerve structure. Yes, you are right- our back.

Our Backbone

Definition: The Backbone or the Spine

Our backbone, as the name suggests, is the central support structure for our body. It connects all the different parts of our system. It not only gives structure to our body but also helps us to sit, stand, walk, bend, and twist with a lot of flexibility and perform many more actions.

Our body is made up of a skeleton which consists of a total of 206 bones in an adult body. The main purpose of the skeleton is to provide a structure and shape to the body. The spine is a sequence of bones that runs the distance between the neck and the back. The spine's distinctive design is why we can move in different ways. Let us have a look at the different parts of the spine.

Parts of Spine

As we all know that the spine has a vital role in our bodies. It not only supports and holds the complete weight of our upper body, but it is also a path for the messages between the brain and the rest of our body.

If you look at a healthy spine, you will see that it has three natural curves and makes an S shape. These curves protect our spine from any injury and absorb any sudden shocks that we feel. The following are some parts of the spine:

1) Vertebrae:

The vertebrae consist of 33 small bones which are assembled one on top of another and form a spinal canal, which helps to protect the spinal cord from the inside. The spinal canal is like a tunnel that protects the spinal cord and the nerves from any kind of injury.

2) Facet Joints:

Facet Joints

Because of the facet joints, we have flexibility and stability in our body, and it also lets us twist and turn. This spinal joint has cartilage, a slippery connective tissue that permits the vertebrae to slide against each other. If someone is complaining about arthritis or even neck pain, then that means there is some concern in the facet joints.

3) Intervertebral Disks:

Intervertebral Disk

The intervertebral disks sit between the vertebrae and act as a flat, round cushion. Its main function is to absorb all the shock of the spine and is also called the spine’s shock absorber. As the intervertebral disks are under constant pressure, each disk consists of a soft gel-like centre that is surrounded by a flexible outer ring to absorb any shock.

4) Spinal Cord and Nerves:

It is a line of nerves that travels through the spinal nerve. The cord moves right from the skull to the lower back. This nerve is the reason that there is a constant transfer of messages between the brain and the muscles.

5) Soft Tissues:

Soft tissues are the ligaments that help vertebrae to hold the spine in position. These tendons connect the muscles to the bone and help in our movement.

Segments of the Spine

Segments of Spine

A human spine consists of a total of 5 spine segments which have a total of 33 vertebrae moving from the top of the spine to the bottom. Below are the distinct sections that make up the division of spinal curves:

The Cervical Spine (Neck)

This is the top part of the spine. It comprises seven vertebrae (C1 to C7) and moves from the neck to the upper back. Its main job is to safeguard the nerves which connect to the brain. It also allows the head to move freely and supports its weight.

This spine is the reason that we can easily tilt, turn and nod our heads. It is like an inward C shape.

The Thoracic spine (Middle Back)

This is the second and the middle part of the spine. It connects the cervical to the lumbar spine and further helps the body to be stable and upright. It has twelve vertebrae (T1 to T12). Our ribs are attached to this spine. It bends out slightly and makes a backward C shape.

The Lumbar Spine (Lower Back)

This is the lower part of the spine and has five vertebrae (L1 to L5) that are a little larger. Its job is to support the upper parts of the spine. As it connects to the pelvis, it nearly bares all body weight. With the help of this spine, we can lift things and carry anything. This spine bends inward and creates a C shape. Now you know that if someone has a back problem, it will beat the Lumbar spine.

The Sacrum (Pelvic)

This part of the spine connects to the hip bones and is in the shape of a triangle and therefore is the bottom part of the spine. The sacrum has five vertebrae (S1 to S5). 

The Coccyx (Tailbone)

Finally, this is the base, also known as the tailbone of the spine. It has four vertebrae that are fused together. Its function is to join the ligaments and muscles around the pelvis.

Interesting Facts About the Backbone

• Did you know that the spine is made up of only 33 bones or vertebrae at birth?

• An adult will have a total of 206 bones in their body.

• You will be surprised to know that the spine has about 120 muscles, 220 individual ligaments, and 100 joints.

• The spinal cord weighs only 35 grams. 

• For a man, the length of a spinal column is 70 cm, and that for a woman is 60 cm.

Role of the Spine

We already know that the spine is an important structure in our body. But are you aware of what exactly a spine does or its role in our body? The spine or the backbone has three quite important roles to play:

To Protect Our Spinal Cord and Its Surrounding Structures: The spine plays the most important role in our body. It acts as armour to our body to protect the entire structure of our body. We won't be able to do anything without the spine as it relays all the messages from the brain to the body and vice versa, allowing us to do what we want to do. It is very important to keep the spine in proper alignment.

It Makes the Foundation of Our Posture: Without the spine, we won't even be able to stand properly. The vertebrae keep our body balanced and maintain the correct posture.

Enable Us to Move and Bend: The spine not only allows us to bend, twist, and turn but also helps our body do amazing things that our body is capable of. Without the spine, our body will be quite stiff.

Fun Facts for Kids:

• It is astounding to know that we share the same number of bones in the neck as that of a Giraffe, i.e. seven.

• The highest bone in our body is called the “atlas”, named after the Titan God Atlas because as he was charged for holding up the sky, so is the spine that holds up our whole head. 

• Even though the spine is connected to the brain, you will be amazed to know that the spinal cord does not always take all commands from the brain, as it has the capability to send direct signals to the muscles.

• Since the spinal cord has a great memory, it can store memory for pain. 

• Isn’t it surprising to know that you are taller in the morning, as your spine has 8 hours without the downward pull of gravity?

• Are you aware that as we age, we get shorter because the cartilage reduces, which makes us decrease in height as we age?

Summary

As we learned today, all the structures of our back need to work together. The human spine, popular as our backbone, consists of a series of bones stretching from our neck to the pelvis. They work together in sync to support our body and enable the body to make movements and, more importantly, send messages from the brain to the rest of the body.

Now that we have complete information on the spine, we can say that the spine plays a crucial role in our body, and we should be able to appreciate it and take care of it better.