Biology · Human Health and Diseases · NEET
An autoimmune disease is when the body's own defence (immune) system stops telling the difference between its own cells and foreign cells. It wrongly sees its own self-cells as enemies and attacks them. This causes damage to the body. NCERT says this happens due to genetic and other unknown reasons.
NCERT names two examples you must know for NEET. First, rheumatoid arthritis, which affects the joints and is very common. Second, myasthenia gravis, which affects the neuromuscular junction and causes fatigue, weakening and paralysis of skeletal muscle. Learn both because NEET asks either one.
Yes. Rheumatoid arthritis is the classic autoimmune disease named directly in NCERT. Do not confuse it with ordinary arthritis (osteoarthritis), which is joint wear-and-tear, or with gout, which is a metabolic uric-acid disorder. Only rheumatoid arthritis is autoimmune.
In allergy, the immune system over-reacts to an outside (foreign) antigen like pollen or dust, releasing histamine. In autoimmunity, the immune system attacks the body's OWN self-cells. Allergy is aimed outward at foreign things; autoimmunity is aimed inward at self.
Normally the immune system can tell 'self' from 'non-self'. In autoimmunity this ability is lost. NCERT states it happens due to genetic and other unknown reasons, so the exact cause is not fully understood. When self-recognition fails, the body damages its own tissues.
Myasthenia gravis is AUTOIMMUNE, not genetic. This is a common NEET trap. It is a chronic autoimmune disorder that affects the neuromuscular junction, leading to fatigue, weakening and paralysis of skeletal muscle. Muscular dystrophy is the genetic muscle disorder, not myasthenia gravis.
In higher vertebrates, the immune system can distinguish self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to:
Which of the following is not an autoimmune disease?
Statement I: Autoimmune disorder is a condition where the body defense mechanism recognizes its own cells as foreign bodies. Statement II: Rheumatoid arthritis is a condition where the body does not attack self cells. Choose the most appropriate answer:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
NCERT says autoimmune diseases happen due to genetic and other unknown reasons. The body loses its ability to tell self-cells from foreign cells, so it attacks and damages its own tissues.
Rheumatoid arthritis (affects joints) and myasthenia gravis (affects the neuromuscular junction). These are the two examples directly linked to NCERT. Systemic Lupus Erythematosus (SLE) has also appeared in a 2024 NEET question.
No. Gout is a metabolic disorder caused by uric-acid crystal deposition, not by the immune system attacking self-cells. NEET often lists gout as a wrong option beside true autoimmune diseases.
It affects the neuromuscular junction. This leads to fatigue, weakening and paralysis of skeletal muscle. Remember: junction between nerve and muscle, so muscle control is lost.
Autoimmunity is the immune system attacking its OWN self-cells. Graft rejection is the immune system attacking a TRANSPLANTED foreign tissue using the cell-mediated (T-lymphocyte) response. One is self, the other is foreign.
