Question

Which of the following bones is the only bone in the body that is not in contact with another bone?
A. Ethmoid bone
B. Atlas
C. Hyoid bone
D. Floating ribs

Answer 1

Hint: Bones are the rigid organs of an animal's body. It is part of the skeletal system. Bones maintain the structure of the body and support the body. Bones are very strong and hard.

Complete Answer:
1. Ethmoid bone: Ethmoid bone is present in the skull.
- It is an unpaired bone that separates the nasal cavity from brain
- Ethmoid bone is located at the roof of the nose, between the two orbits.
- The ethmoid bone is the bone that makes up the orbit of the eye.

2. Atlas: The Atlas is the first bone of the seven cervical vertebrae.
- This bone supports the weight of the skull. It is located in the neck.
 It is named as Atlas because of a myth that as Atlas supported the globe, it supports the entire head.
- It forms the joining part between the skull and spine.

3. Hyoid bone: Hyoid bone is also called a lingual bone or tongue bone.
- It is a horse-shoe shaped bone.
- It is situated in the anterior midline of the neck between the chin and the thyroid cartilage.
- The hyoid bone is distantly attached to other bones with the help of muscles or ligaments.
- It has no articulation with other bones.

4. Floating ribs: Floating ribs refer to the two lowermost, the eleventh and twelfth rib pairs.
- These ribs are named as floating ribs because they are only attached to the vertebrae and not attached to the sternum.
Hence, from the above discussion it is clear that Hyoid bone is the one that is not in contact with another bone.

So, option C is the right answer for this question.

Note: Hyoid bone is U-shape bone. It consists of a pair of larger horns called as greater coruna and a pair of smaller horns called as lesser coruna.