Human Immunity and Blood

Antiserum contains antibodies to provide immunity to the body.

CD 8 is a transmembrane glycoprotein present in suppressor T cells.

If they produced anti-A antibodies, it would destroy their own blood. However, they do normally produce anti-B antibodies since B type blood would be alien to them.

Karl Landsteiner discovered the ABO system in 1900 and 1901 while trying to understand why blood transfusions sometimes saved lives and at other times caused death.

All the above statements are correct.

Lymphocytes are a type of white blood cells, which are responsible for protecting our body against bacterial and viral infections. They make up fifteen to forty percent of the total white blood cells that circulate in the blood stream. The two main types of lymphocytes are T cells and B cells, and both help to fight off infection and play a role in stopping the growth of cancers.

Blood group O individuals do not have either A or B antigens on the surface of their RBCs. But their blood serum contains IgM anti-A and anti-B antibodies against the A and B blood group antigens. Therefore, an individual of blood group O can receive blood only from a group O individual, but can donate blood to individuals of any ABO blood group (i.e. A, B, O or AB). They are known as universal donors.

Progenitor cells are early descendants of stem cells that can differentiate to form one or more kinds of cells. After wounding, only stem cells contribute substantially to the repair and long-term regeneration of the tissue, whereas committed progenitor cells make a limited contribution.

This condition is called polycythemia.

Thymus is a small organ in the upper chest, under the breastbone. Before birth and during childhood, thymus helps the body to make a type of white blood cells. These cells protect our body from infections.

Basophils remain in blood for short duration, and later migrate to the tissues. Basophils liberate heparin, an anticoagulant substance, which produce allergic reactions. They also liberate small quantities of bradykinin and serotonin, which participate in inflammatory process.

It is the cancer of blood cells. The bone marrow starts to make a lot of abnormal WBC called leukemia cells, which grow faster than normal cells. Leukemia cells can crowd out the normal blood cells. This can lead to serious problems such as anaemia, bleeding and infections.

Colony Stimulating Factors (CSFs) are secreted glycoproteins that bind to receptor proteins on the surfaces of hematopoietic stem cells, and stimulate stem cells in bone marrow to form specialised white blood cells that defend the body against infection from viruses. It can also be produced by fibroblasts, macrophages and endothelial cells.

When we are exposed to a variety of harmful pathogens such as bacteria, viruses, fungi and parasites which can cause diseases, our body has a specific defence mechanism to protect our body from these pathogens. Leucocytes or white blood cells play a major role in body's defence mechanism. In leucocytes, neutrophils are considered the first line of defence against infection.

Erythrocyte sedimentation rate is the rate at which red blood cells settle down. It is the measure of supernatant plasma separated out at the end of 1 hr when a column of blood mixed with an anticoagulant is kept undisturbed. ESR is increased in pregnancy and during menstruation, and also in infections like tuberculosis, rheumatoid arthritis, malignancy and anemia. ESR decreases in polycythemia and sickle cell anemia.