Question

11th and 12th pair of ribs which are imperfectly formed and do not reach the sternum are called
A) Pseudo ribs
B) False ribs
C) Floating ribs
D) Visceral ribs

Answer 1

Hint: In most vertebrates, the rib cage is an arrangement of ribs linked to the spinal column and sternum in the thorax that encloses and protects critical organs like the heart, lungs, and major vessels.

Complete answer:
Humans have 12 pairs of ribs on average. True ribs are the first seven pairs of ribs that are attached directly to the sternum by costal cartilages. The 8th, 9th, and 10th pairs of false ribs are attached to the 7th rib by cartilage rather than directly joining the sternum.( If a rib does not connect to the sternum, it is considered to be a false rib. (the breastbone))

The 11th and 12th pairs of ribs, referred to as floating ribs, are half the size of the others and do not extend to the front of the body. Each true rib has a tiny head with two articular surfaces: one that articulates with the body of the vertebra and another that articulates with the tip of the vertebra's transverse process. A narrow portion behind the head of the rib is known as the neck, and the remainder is known as the shaft.

True ribs: True (or sternal) ribs are the first seven ribs that join the sternum (breast bone) in the front.
False ribs: False ribs are the lower five ribs that do not join straight to the sternum.

Therefore the correct answer is option ‘C’.

Note: The costal cartilages of the ribs slightly above the upper three false ribs link to the costal cartilages of the ribs above them. The last two false ribs, on the other hand, are known as floating, fluctuating, or vertebral ribs since they have no ventral attachment (no anchor at all in front).