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Sternum

life science Maturity 11-13 Next article →

The sternum is a long, flat bone in the center of your chest.

Body of sternum - close-up - animation
Body of sternum - close-up - animation

Many people call it the breastbone. It sits right in the middle of the front of your chest. This bone is one of the largest flat bones in your body. It works like a shield for your heart and lungs.

Xiphoid process - close-up - animation
Xiphoid process - close-up - animation

It also protects your major blood vessels from injury. The bone connects to your ribs using pieces of cartilage. This cartilage helps form your rib cage.

Your sternum has three main parts that work together. The top part is called the manubrium, which is Latin for "handle."

Manubrium - animation
Manubrium - animation

It is a wide, four-sided shape at the top of your chest. The middle part is the body, also called the gladiolus. This is the longest part of the entire bone. The bottom part is the xiphoid process. This is a small, pointed piece at the very end. The whole bone is shaped roughly like a necktie.

This bone grows through a process called ossification.

Gray118
Gray118

It begins as two soft bars of cartilage on the left and right sides. These two bars eventually fuse together in the middle. The bone forms from six different centers of growth. One center forms the manubrium and one forms the xiphoid process. Four centers form the body of the bone. These centers appear in a specific order as you grow. The manubrium and the first part of the body begin to harden during the sixth month of life in the womb.

Growth happens at different speeds for different people.

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Gray119

The different pieces of the body start to join together around puberty. By the age of 25, all the parts are usually united. The xiphoid process can take a very long time to finish. It might join the body before age 30, but sometimes it stays separate even in old age. Females often finish growing this bone earlier than males do. Some people might even have a small hole in their bone called a sternal foramen.

Doctors sometimes look at the sternum to help patients.

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Gray120

Because the bone contains bone marrow, it is a place for a bone marrow biopsy. This is a medical test used to check health. The sternum can also be injured in accidents. A person might fracture the bone if they hit a steering column in a car. In some surgeries, doctors must cut the bone open to reach the heart. This is called a median sternotomy. They then use wires or plates to hold the bone together while it heals.

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🖼️ Images & Media (8)
File:Manubrium - animation.gif
Manubrium - animation.gif
File:Body_of_sternum_-_close-up_-_animation.gif
Body_of_sternum_-_close-up_-_animation.gif
File:Xiphoid_process_-_close-up_-_animation.gif
Xiphoid_process_-_close-up_-_animation.gif
File:Gray118.png
Gray118.png
File:Gray119.png
Gray119.png
File:Gray120.png
Gray120.png
File:Gray121.png
Gray121.png
File:Medusterdisloca.png
Medusterdisloca.png
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