Which of the following $U$-shaped bones is independently situated in the human body and provides support to the tongue?

Twelve pairs of ribs and twelve pairs of cranial nerves are found in

The axis vertebra can be identified by which of the following?

The Haversian system is found in:

The zygomatic bone is a part of which of the following?

An elderly woman slipped in the bathroom and had severe pain in her lower back. After $X-ray$ examination,doctors told her it is due to a slipped disc. What does that mean? How does it affect our health?