Question

Floating ribs of man are ________ pairs.
(a) 2
(b) 3
(c) 5
(d) 8

Answer 1

 
Hint: Typically, there are 12 pairs of ribs in all. The building blocks of the spine (the vertebrae) in the back are connected to any pair of ribs. There are in total 5 pairs of false ribs out of which 3 pairs connect to the costal cartilages of the ribs just above them and the remaining pairs have no ventral attachment.

Complete Step by Step Answer: When the ribs do not bind to the sternum (the breast bone) or another rib, a rib is considered to be 'floating'. The last 2 pairs of ribs are the ribs that float.

Additional Information: - In the thorax of most vertebrates, the rib cage is the arrangement of ribs attached to the vertebral column and sternum, which encloses and protects the heart and lungs. In humans, the rib cage is a bony and cartilaginous structure that surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton, also known as the thoracic cage. The sternum and xiphoid process, the costal cartilage, and the 12 thoracic vertebrae in a typical human rib cage are 24 ribs in 12 pairs.

- The terms true ribs and false ribs describe pairs of ribs that are attached to the sternum directly or indirectly. The true ribs are the first seven pairs of ribs known as the fixed or vertebrosternal ribs as they attach directly to the sternum; the false ribs are the next five pairs (eighth to twelfth). Vertebrochondral ribs and vertebral ribs are both included in the false ribs. Three pairs (eighth to tenth) of vertebrochondral ribs are connected indirectly to the sternum through the costal cartilage of the ribs above them. For respiratory activity, their elasticity allows the rib cage movement.
The floating rib or vertebral rib term refers to the two lower rib pairs, the eleventh and twelfth rib pairs; so-called because they are only attached to the vertebrae, not the sternum or sternum cartilage. Relatively small and delicate, these ribs include a cartilaginous tip.
So, the answer is, “2.”

Note: - The spaces between the ribs are known as intercostal spaces; they include the intercostal muscles, and neurovascular bundles containing nerves, arteries, and veins. - In extreme cases, which have little to do with gender, for a total of 13 pairs of ribs, a person might turn up sporting extra lumbar ribs, just like our distant cousins, the gorillas. Thus, it's popularly known as the "gorilla rib." - The number of mammalian ribs ranges from 9 (whale) to 24 (sloth); the number of true ribs ranges from 3 to 10 pairs.