Out of 'X' pairs of ribs in humans, only 'Y' pairs are true ribs. Select the option that correctly…

Out of 'X' pairs of ribs in humans, only 'Y' pairs are true ribs. Select the option that correctly represents values of X and Y and provides their explanation:
  1. X=12, Y=7 True ribs are attached dorsally to vertebral column and ventrally to the sternum
  2. X=12, Y=5 True ribs are attached dorsally to vertebral column and sternum on the two ends
  3. X=24, Y=7 True ribs are dorsally attached to vertebral column but are free on ventral side
  4. X=24, Y=12 True ribs are dorsally attached to vertebral column but are free on ventral side

Solution

In human, 12 pairs of ribs are present in which 7 pairs of ribs ( 1st to 7th pairs) are attached dorsally to the vertebral column and ventrally to the sternum. That is the reason, they are called as true ribs. There are false ribs and floating ribs in human thoracic cage bones.

Asked in: NEET 2017

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