Ribs and Rib Cage MCQ - Practice Questions with Answers

• The sternum is a flat bone present just under the skin in the middle of the front of the chest. 
• It is about 15 cm long. 
• It consists of three parts— the manubrium is the uppermost part, the body is the middle portion and the xiphoid process is the tip of the bone. 
• The true ribs (7 pairs) are attached to the sternum.
• It protects the internal organs in the thoracic region. 
• It also provides the surface for muscle attachment. 
• The sternum helps in the respiratory mecha­nism.

• There are 12 pairs of ribs which form the bony lateral walls of the thoracic cage.
• Each rib is a thin flat bone connected dorsally to the vertebral column and ventral attachements differ
• All the ribs have two articulation surfaces on their dorsal end and is hence are called as Bicephalic Ribs
• Depending on the ventral attachment of the ribs, there are three types of Ribs

1. The first seven pairs are called true ribs because their anterior ends are attached directly to the sternum by means of small pieces of hyaline cartilage, the costal cartilages. These are Vertebrosternal Ribs
2. The eighth, ninth and tenth pairs of ribs are called false ribs or Vertebrochondra Ribs. They articulate by cartilage with costal cartilage of the seventh rib and thus are attached indirectly to the sternum.
3. Last 2 pairs (11th and 12th) of ribs are not connected ventrally and are, therefore, called floating ribs.These are also known as Vertebral Ribs as only dorsal attachment is present

• Thoracic vertebrae, ribs and sternum together form the rib cage.

NOTE : Rarely in some people there is the presence of the extra pair of floating ribs i.e 13th pair of ribs. Much like our distant cousins, the gorillas. Thus, it' is known as a "gorilla rib.". Hence Gorilla rib is an extra floating rib.