At which of the following sites is cartilage not found?

Options

A. Embryonic endoskeleton
B. Between the cranial bones
C. Tip of the nose
D. Between the vertebra

Answer

To determine where cartilage is not found, we need to analyze the options provided and understand the types of cartilage and their locations in the human body.

### Step-by-Step Solution:

1. **Understand what cartilage is**: Cartilage is a specialized connective tissue that provides both flexibility and rigidity. It plays a crucial role in the skeletal system.

2. **Identify the types of cartilage**:
- **Hyaline Cartilage**: This is the most common type of cartilage, which is translucent and has no fibers. It is found in places like the nasal septum, coastal cartilages (connecting ribs to the sternum), and the tip of the nose.
- **Fibrocartilage**: This type is tougher and contains collagen fibers, providing strength and slight movement. It is found in intervertebral discs (between vertebrae).
- **Elastic Cartilage**: Composed of elastic fibers, this type is found in structures like the pinna (outer ear) and the epiglottis.

3. **Evaluate the options**:
- **Embryonic Skeleton**: Cartilage is present in the embryonic skeleton, as it forms the basis of the skeletal structure before ossification into bone.
- **Between Cranial Bones**: In the adult skull, cranial bones are fused together and do not contain cartilage.
- **Tip of the Nose**: The tip of the nose is made up of hyaline cartilage.
- **Intervertebral Discs**: These discs are made of fibrocartilage, which provides cushioning between the vertebrae.

4. **Conclusion**: Based on the analysis, the site where cartilage is not found is **between the cranial bones**.

### Final Answer:
The correct option is **between the cranial bones** where cartilage is not found.