The Biology Project: Immunology

Immunology Problem Set

Problem 2: Cord blood transplants

Tutorial to help answer the question:


A. Erythrocytes (red blood cells)
B. Leukocytes (granulocytes, monocytes and lymphocytes)
C. Stem cells


Hematopoietic stem cells

In humans, the immune system begins to develop in the embryo. The immune system starts with hematopoietic (from Greek, "blood-making") stem cells. Stem cells differentiate into the major players in the immune system (granulocytes, monocytes, and lymphocytes). Stem cells also differentiate into cells in the blood that are not involved in immune function, such as erythrocytes (red blood cells) and megakaryocytes (for blood clotting). Stem cells continue to be produced and differentiate throughout your lifetime. Cord blood is an excellent source of stem cells. The figure below is a summary of stem cell differentiation.
By the time a baby is born, the immune system is a sophisticated collection of tissues that includes the blood, lymphatic system, thymus, spleen, skin, and mucosa.


Problem 2 | Answer | Problem 3

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