What Is Creatinine? Creatinine is a chemical waste product in the blood that passes through the kidneys to be filtered and eliminated in urine. The chemical waste is a by-product of normal muscle function. The more muscle a person has, the more creatinine they produce. Levels of creatinine in the blood reflect both the amount of muscle a person has and their amount of kidney function.
The lymph system and lymphoid tissue. To know what lymphoma is, it helps to understand the bodyâs lymph system. The lymph system (also known as the lymphatic system) is composed mainly of lymphoid tissue, lymph vessels, and a clear fluid called lymph.Lymphoid tissue includes the lymph nodes and related organs that are part of the bodyâs immune and blood-forming systems, such as the spleen and bone marrow.ymphocytes. Lymphoid tissue is made up of several types of immune system cells that help the body fight infections. Most of the cells in lymphoid tissue are lymphocytes, a type of white blood cell. The main types of lymphocytes are B lymphocytes (B cells) and T lymphocytes (T cells).
Lymph nodes: Small, bean-shaped structures that produce and store cells that fight infection and disease and are part of the lymphatic system â which consists of bone marrow, spleen, thymus and lymph nodes, according to A Practical Guide To Clinical Medicine from the University of California San Diego (UCSD).