1. It is at its greatest in children.

2. With puberty, it eventually shrinks and is replaced by fat.

3. It produces and secretes thymosin, an essential hormone for T cell development and production.

4. Thymus gland is a small organ located under the breast bone in the upper chest.

5. It produces white blood cells, called lymphocytes, which protect the body from infection.

Hairlike structures called cilia line the mucous membrane and move the particles trapped in the mucus out of the nose. Inhaled air is moistened, warmed, and cleansed by the tissue that lines the nasal cavity.

1. Rickets is a bone disease caused by vitamin D deficiency.

2. Due to rickets, the absorption of calcium and phosphorus in the bones decreases.

3. The solution to protect exclusively breastfed babies from this disease is Vitamin D supplements.