Structural Organisation in Animals

Epithelial and gland cells are packed closely into layers, and muscle cells form bundles and sheets.
Nerve cells (neurons) are structurally separate units. They do not form a continuous layer, and they are not even in direct cytoplasmic contact with each other; they communicate across synapses (small gaps).
So nerve cells do not form a layer and remain structurally separate.

The nasal septum, the tip of the nose, the trachea and the ends of long bones are made of hyaline cartilage.
To repair the nasal septum, the same type of cartilage, hyaline cartilage, is preferred, because it has the right firmness and flexibility.
Elastic cartilage is found in the pinna and epiglottis, and fibrous cartilage in intervertebral discs.
So hyaline cartilage is preferred.