It is widely known that all vertebral species have ribs1. Humans have a complex rib cage2 which comprises of the sternum3, ribs and some other parts. Every doctor knows how many ribs people have, but an ordinary man can have some difficulties with such a question. In fact, it is no difficult to memorize the answer:
Every human (both men and women) has 24 coupled ribs (that is, 12 pairs)
The first fourteen ribs (seven pairs) are directly connected to the breastbone (sternum).
They are called "true ribs". The very first pair is difficult to distinguish from the rest of human ribs. These ribs are flat, short, and C-shaped. They are attached below the neck. The other six pairs of ribs look more usual.
The next five pairs of ribs are called "false ribs". Three of them have a cartilaginous attachment to the sternum, and the last two (pairs eleven and twelve) are known as "floating ribs". Once in a while they are also termed vertebral ribs because they are connected solely to the vertebrae. Some humans miss one pair of floating ribs, and some have three pairs of them due to genetic mutations.
As a rule, the length of ribs increases starting from pair one and decreases from the eighth pair. The diaphragm4 controlling breathing separates the rib cage from the abdomen. The diaphragm’s contraction makes the rib cage along with the thoracic cavity expand which reduces intrathoracic pressure and fills the lungs with air.
The main purpose of the rib cage is to protect the internals (the heart, lungs, and kidneys) in the thoracic cavity. The ribs make a cage-like formation around them, playing an important role in the skeleton. That is why this structure is called the rib cage though it consists of some other bones too.
Many people do believe than men and women have different number of ribs. The origin of this belief lies in the Bible, and we all know the story of Adam and created from his rib Eve. In point of fact, the quantity of ribs does not depend on sex. Both men and women have twelve pairs of ribs. If this statement cannot convince you, take X-ray pictures of several men and women. This will be the strongest visual proof.
We hope that this piece of information is enough to give you the exhaustive answer to the question, "How many ribs do humans have?".
A rib is one of the 24 slender curved bones forming the rib cage. They serve to protect internal organs in the thoracic cavity.
The rib cage (also called the thoracic cage) is the structure formed by ribs and other bones. As a rule, a human rib cage has twenty four ribs, the sternum, the twelve thoracic vertebrae, and costal cartilages.
The sternum is the long bone in the shape of the capital letter
The diaphragm is a muscular partition extending across the rib cage’s bottom and separating the thoracic cavity from the abdomen in humans and mammals. It plays an important role in respiration because its contraction spreads the thorax and inflates the lungs.