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Thorax | Thorax Anatomy

The Thorax and the Anatomy of  The Thorax

The chest, also known as the thorax, consists of 25 bones in the human body.  These bones are the sternum and the ribs.

The chest is a region located between the head and the abdomen. It houses and protects many internal organs, such as the lungs and heart.

Below are detailed diagrams and information regarding the chest bones and chest bones anatomy. You can find the names and lists of the bones of the chest.

Chest bones

List of all Chest Bones


  • sternum (1)
  • ribs (2 x 12)

Sternum bone

Sternum bone

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The sternum is a long, elongated bone shaped like a capital T.

This flat bone consists of three parts,

  • the manubrium,
  • the body of the sternum (gladiolus),
  • and the Xiphoid process – labeled in the diagram to the side.

The sternum is located in the middle of the thorax, in between the two sets of ribs.

  • Early on during development, the sternum is divided into 3 regions, each known as sternebra. The average length of the sternum is approximately 17 cm.
  • The sternum connects to the ribs via cartilage.
  • The primary function of the sternum is the protection of the heart, lungs, and blood vessels from physical damage.
  • Most of the sternum is made up of vascular tissue, only a thin layer of bone covers the outside of this tissue.

The bone is thickest in the manubrium.

Rib bones

Rib Bones

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  •  The body consists of 24 ribs, 2 sets of 12 ribs on each side of the thorax.
  • Collectively, these long curved bones make up a structure known as the ribcage that surround the entire chest.
  • Like the sternum, the ribcage functions in protecting the vital organs and blood vessels.

Furthermore, the ribcage expands and contracts along with the lungs to allow for efficient breathing.

In the ribcage, the first 7 ribs are known as “true ribs.”

  • These bones are connected directly to the sternum via a specific type of cartilage known as costal cartilage.
  • The cartilage allows for the ribs to move and adds to the elasticity of the entire rib cage.

The other 5 ribs are known as “false ribs.”

  • Of these 5 ribs, 3 ribs connect to the sternum via cartilage.
  • The other 2 however have no connection to the sternum and only connect to the vertebrate. As a result, these 2 ribs (the 11th and 12th ribs) are known as floating ribs or vertebral ribs.

The Thorax bones for you.

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Test Your Knowledge

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An adult has a total of 206 bones in their skeleton

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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.

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