The ribs are vital bones of the body, protecting vital organs. If you want to know the number of ribs humans have, and know more about their structure and function, keep reading.

The ribs protect the vital organs of the body, and hence, are among the most important bones in the human body. They form a cage-like structure around the vital organs, and due to this, all the ribs are collectively called the rib cage. However, there are other bones besides the ribs that make up the rib cage. In the following paragraphs, we tell you more about the functions and importance of the rib cage.

The Human Rib Cage

All vertebrates have ribs. Humans, being complex evolved animals, have a complex rib cage, that comprises the ribs and sternum. Since the rib cage is present in the chest or thorax, it is also known as the thoracic cage. The ribs are attached to the sternum in the front and thoracic vertebrae in the back; they also support the pectoral girdle, more commonly known as the collarbone. The sternum is a strong bone placed right in front of the vital organs. It is very difficult to crack this bone, but at the same time ribs can be fractured easily. Sometimes rib pain may arise due to a torn cartilage. However, it is important to remember that a fracture or cartilage injury is not always the reason for this pain. Rib cage pain can be caused due to various other reasons.

Coming to the number of ribs in the human body, there are 12 pairs in the human body that is 24 in all. They are further categorized as true ribs, false ribs, and floating ribs, depending on their attachment to the parts of sternum. The sternum anatomy is quite simple and it is divided into manubrium, gladiolus, and xiphoid process.

True Ribs
These are the first seven pairs of ribs in the rib cage. They are called true ribs because they are directly attached to the sternum. These have costal cartilages by which they attach to the head of the sternum.
False Ribs
These consist of the eighth, ninth, and tenth pair of ribs. They attach themselves to the costal cartilages of true ribs and not the sternum directly.
Floating Ribs
Pair eleven and twelve are not attached to the sternum or any other bone or cartilage, and therefore known as floating. Even though they do not attach in the chest, they are attached to the vertebrae in the back.
Parts of a Rib

The rib is an elongated curved bone and is divided into following parts.

The front, is close to the vertebral column. The neck is the flattened portion. The tubercle is an eminence to attach other bones, and the angle is the curved part of the rib. It also consists of something known as the costal grooves which contains the intercostal nerve and vessels. The 1st, 2nd, 10th, 11th, and 12th rib are called atypical ribs as each of their structure differs slightly. This is mostly because of their location.

Function of Ribs

The main function of the rib cage is protection of the heart and lungs. The rib cage also forms a part of the respiratory system. It assists an individual in the process of breathing, that is inhalation and exhalation. The muscles of the ribs help in lifting up the rib cage and providing the lungs space for expansion on inhalation. The contraction of these muscles helps in expelling the air out from the lungs. Thus contraction and relaxation of these rib muscles help in breathing.

According to the Biblical story of Adam and Eve it is believed that women have an extra rib, as a woman was created from a man's rib. However, on observing a chest X-ray of a man and a woman, you will see that both men and women have the same number of ribs and that is 24.