GENERAL HISTOLOGY

Detailed explanation-1: -The thymus gland is quite big in babies and children. It reaches its biggest weight of about 1 ounce during puberty. After puberty, it begins to shrink, and in older adults, it’s rather small.

Detailed explanation-2: -T cells and B cells derive their names from the organs in which they develop. T cells develop in the thymus, and B cells, in mammals, develop in the bone marrow in adults or the liver in fetuses.

Detailed explanation-3: -At the outer edge of the cortex, in the subcapsular region of the thymus (Fig. 7.13), large immature double-negative thymocytes proliferate vigorously; these cells are thought to represent the thymic progenitors and their immediate progeny and will give rise to all subsequent thymocyte populations.