Courses for Kids
Free study material
Offline Centres
Store Icon

Rib Bone

share icon
share icon


Invertebrate anatomy, human ribs are part of the axial skeleton, are the long curved bones that shape the rib cage. In most tetrapods, ribs cover the chest, allow the lungs to expand, and thus facilitate breathing by expanding the chest cavity. Ribs help to protect the lungs, heart, and other internal organs of the thorax. The ribs include 24 bones in 12 pairs which form the protective cage of the thorax. They protect the thoracic internal organs. There is a chance that 1 in 500 people have an extra rib called a cervical rib.

Rib Features

Ribs are flat bones that form part of the rib cage to serve internal organs. Human ribs generally have 24 ribs, in 12 pairs. 1 in 500 people has an extra rib called a cervical rib. All are connected at the back to the thoracic vertebrae and are numbered from 1-12. The thoracic vertebra is attached to the first rib. At the front of the human body, most of the ribs are connected by costal cartilage to the sternum. Human ribs are connected to the vertebrae at the costovertebral joints.The rib includes the head, neck, body, tubercle, and angle.

The top of the rib lies next to a vertebra. The ribs joined to the vertebrae with two costovertebral joints, on the head and one on the neck. The top of the rib has a superior and an inferior articulating region, detached by a crest. These articulate with the superior and inferior costal facets attached to the vertebrae. The crest is connected to the intra-articular ligament that combines the rib to the vertebrae of the same number, at the intervertebral disc. On the other side, the radiant ligament joins the top of the rib to both the body of the upper vertebra. The smaller part of the ligament connects to the intervertebral disc. This plane joint is called the articulation of the head of the rib.

What is Rib Cage?

  1. The ribs include 24 bones in 12 pairs which generate the protective cage of the thorax.

  2. Their ribs protect the thoracic internal organs.

  3. The region of vertebrae of the thoracic have very limited movement and provide support to the rib cage and protect the lungs and heart.

  4. On the posterior side, 12 pairs of rib bones articulate with the thoracic vertebrae on the posterior side.

The first seven sets of ribs, called true ribs, are connected to the sternum by the costal cartilage. The top rib is different and easier to distinguish than other ribs. They are short, flat, C- shaped bone, and connected to the manubrium. The vertebral is attached to the neck at the first thoracic vertebra. The major part of the bone is found above the level of the clavicle.

Types of Ribs

There are generally three types of ribs which are allocated to one of three distinct types;

True ribs (vertebrosternal)

False ribs (vertebrochondral)

Floating ribs (vertebral free)

The Function of the Rib Cage

The human skeletal system provides a structural framework and supports the body, made up of 206 bones in an average age human. It includes cartilage, bones, ligaments, and tendons that connect bones and bones to muscles. The rib is part of the skeletal system which gives structure to the body, and also gives proper shape to the body. The main function of ribs is to protect the internal organs including the heart, lungs, and thorax.

Want to read offline? download full PDF here
Download full PDF
Is this page helpful?

FAQs on Rib Bone

1. What is Rib?

Ans. It is a set of twelve paired bones that form the protective 'cage' of the thorax.

2. What are False Ribs and Floating Ribs?

Ans. False rib: From the second rib through 7 have handed down appearance and become longer and less curved as they progress downwards, the following five sets are called "false ribs". 8-12 rib pairs are connected to vertebrae posteriorly, but anteriorly they are not connected to the sternum directly. These rib pairs are false ribs. 

11 and 12 pairs of ribs are not attached to the sternum, these two rib pairs are known as the floating ribs.

3. Where are Ribs Located?

Ans. The first seven pairs of ribs are connected to the sternum or breastbone by cartilage in the anterior thorax, and in the costal cartilage, the eighth, ninth, and tenth ribs are attached to each other. The lower 5 ribs are not connected to the sternum.

 4. What are the True Ribs?

True ribs are the first seven ribs attached to the sternum (the breast bone) in the front.

5. What are the False Ribs?

The five lower ribs that do not directly connect to the sternum are the false ribs.