MCQ IN MEDICINE

Detailed explanation-1: -The immune system is a complex network of organs, cells and proteins that defends the body against infection, whilst protecting the body’s own cells. The immune system keeps a record of every germ (microbe) it has ever defeated so it can recognise and destroy the microbe quickly if it enters the body again.

Detailed explanation-2: -Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system’s antibodies and other cells to target the invader.

Detailed explanation-3: -The immune system protects the body from possibly harmful substances by recognizing and responding to antigens. Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria.

Detailed explanation-4: -The body reacts to disease-causing bacteria by increasing local blood flow (inflammation) and sending in cells from the immune system to attack and destroy the bacteria. Antibodies produced by the immune system attach to the bacteria and help in their destruction.