JNTU B.Pharmacy I Year HUMAN ANATOMY AND PHYSIOLOGY - II Previous Question Paper (December-2018/ January-2019 - R17)

A mismatched blood transfusion triggers an acute hemolytic transfusion reaction. The recipient's antibodies recognize the donor's red blood cells as foreign antigens, leading to agglutination (clumping) and subsequent hemolysis (destruction) of the transfused cells. This process releases free hemoglobin into the bloodstream, which can cause severe complications such as fever, chills, hypotension, hemoglobinuria, and potentially fatal acute renal failure due to the blockage of renal tubules.

B cells, T cells, and natural killer (NK) cells are essential components of the adaptive and innate immune systems, performing the following functions:

• B cells: Responsible for humoral immunity. Upon activation, they differentiate into plasma cells that produce specific antibodies (immunoglobulins) to neutralize pathogens and mark them for destruction, and memory B cells that provide long-term immunity.
• T cells: Responsible for cell-mediated immunity. Helper T cells (CD4+) coordinate the immune response by releasing cytokines, while Cytotoxic T cells (CD8+) directly identify and induce apoptosis in virus-infected or cancerous cells.
• Natural Killer (NK) cells: Part of the innate immune system, they provide rapid responses to virally infected cells and tumor cells. They function by detecting the absence of MHC class I molecules on target cells and releasing perforins and granzymes to destroy them.