The number of ribs contact with sternum

The number of ribs contact with sternum:

• a- 7
• b- 14
• c- 18
• d- 24

The correct answer is a. 7.

There are 12 pairs of ribs in humans, but not all directly connect to the sternum. Only the first 7 pairs of ribs, known as true ribs, have direct cartilage attachments to the sternum. The remaining 5 pairs, called false ribs, either connect indirectly to the sternum through the cartilage of other ribs or have no direct connection at all.

Therefore, only 7 ribs directly contact the sternum.

Other Options:

Here's a breakdown of the other options:

- b. 14:

This is incorrect because it includes all pairs of ribs, not just those that directly connect to the sternum.

- c. 18:

This is also incorrect because it significantly overestimates the number of ribs and includes false ribs that don't connect to the sternum.

- d. 24:

This is the total number of ribs in a human, but not all connect to the sternum.

Remember, the number of true ribs is a consistent anatomical feature in humans, and understanding this detail is important for various medical and biological applications.