thick. It increases in size until puberty, where it may have a size of about 40-50 g, following which it decreases in size in a process known as involution.

The thymus is located in the anterior mediastinum. It is made up of two lobes that meet in the upper midline, and stretch from below the thyroid in the neck to as low as the cartilage of the fourth rib. A capsule covers the lobes. The thymus lies behind