- Exam
- NEET
- Year
- 2019
- Subject
- Zoology
- Chapter
- Locomotion and Movement
NEET 2019 · Zoology · Locomotion and Movement
Select the correct option.
Options
- A8th, 9th and 10th pairs of ribs articulate directly with the sternum.
- B11th and 12th pairs of ribs are connected to the sternum with the help of hyaline cartilage.
- CEach rib is a flat thin bone and all the ribs are connected dorsally to the thoracic vertebrae and ventrally to the sternum.
- DThere are seven pairs of vertebrosternal, three pairs of vertebrochondral and two pairs of vertebral ribs.
Correct answer
D. There are seven pairs of vertebrosternal, three pairs of vertebrochondral and two pairs of vertebral ribs.
Step-by-step solution
Each rib is a thin flat bone connected dorsally to the vertebral column and ventrally to the sternum. It has two articulation surfaces on its dorsal end and is hence called bicephalic. First seven pairs of ribs are called true ribs. Dorsally, they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage. The 8th, 9th and 10th pairs of ribs do not articulate directly with the sternum but join the seventh rib with the help of hyaline cartilage. These are called vertebrochondral (false) ribs. Last 2 pairs (11th and 12th) of ribs are not connected ventrally and are therefore, called floating ribs. Thoracic vertebrae, ribs and sternum together form the rib cage.