Ribs : There are twelve pairs of ribs. The ribs are of three types :

1. True ribs : There are seven pairs of true ribs. At one end they are attached to vertebral column and at the second end they are attached to sternum.

2. False ribs : There are three pairs of false ribs. At one end these are attached to vertebral column and at second end these get attached to each other.

3. Floating ribs : There are two pairs of floating ribs. These are attached to vertebral column and the second end is free.