Which of the following statements is not true regarding ribs in humans ?

Options

A. Rib is a flat bone connected dorsally to vertebral column
B. Ribs are ventrally connected to sternum through hyaline cartilage
C. Vertebro - chondral ribs directly articulate with sternum with the help of hyaline cartilage
D. In humans ribs are bicephalic

Answer

To determine which statement is not true regarding ribs in humans, let's analyze each statement step by step:

1. **Statement 1**: "Rib is a flat bone connected dorsally to the vertebral column."
- **Analysis**: This statement is true. Ribs are indeed classified as flat bones and they connect to the vertebral column at the back (dorsally).

2. **Statement 2**: "Ribs are ventrally connected to the sternum through hyaline cartilage."
- **Analysis**: This statement is also true. The ribs connect to the sternum at the front (ventrally) via hyaline cartilage, which allows for flexibility and movement.

3. **Statement 3**: "Vertebrochondral ribs directly articulate with the sternum with the help of hyaline cartilage."
- **Analysis**: This statement is not true. The vertebrochondral ribs (which are the 8th to 12th pairs of ribs) do not directly articulate with the sternum. Instead, they are indirectly connected to the sternum through the costal cartilage of the ribs above them. Therefore, this statement is incorrect.

4. **Statement 4**: "The human ribs are bicephalic."
- **Analysis**: This statement is true. The term "bicephalic" refers to the two-headed structure of the ribs, which is accurate as each rib has two articulating surfaces (heads) that connect to the vertebrae.

**Conclusion**: The statement that is not true regarding ribs in humans is the third statement: "Vertebrochondral ribs directly articulate with the sternum with the help of hyaline cartilage."