CD4+ T cells, or helper T cells, are one type of lymphocyte that helps coordinate the immune response against infection and disease. They interact and activate other cells in the immune system. The ...

An essential component of the lymphatic system, the thymus, a pyramid-shaped organ located in the thoracic cavity, is responsible for producing T-cells. For centuries, the thymus was believed to be an ...

The energy for various functions of the human body comes from the nutrient molecules that have been broken down, in a process called metabolism. Metabolism comprises of two major parts: anabolism ...

This image depicts the chemical structure of cytosine. It shows a hexagonal ring with nitrogen atoms at positions 1 and 3, and a primary amine group attached to carbon 4. The two remaining positions ...