Answer:
An autoimmune disease occurs when the body does not recognize its own cells.
Step-by-step explanation:
In an autoimmune disease, the body's immune system fails to recognize its own cells, and attacks them as if they were foreign agents.
The immune system, or defense system, is a collection of cells and substances —such as antibodies— that are responsible for defending the body against foreign and potentially harmful agents, such as disease-causing microbes.
A genetic predisposition and some external factors can trigger an abnormal response of the defenses, which begin to attack the healthy cells of the body, producing defined clinical conditions.
An example of an autoimmune disease is Systemic Lupus Erythematosus, where the defenses attack the connective tissue.
The other options are not correct because:
- In autoimmune disease the body does not recognize its own cells, not itself.
- The blood is not the primary target of autoimmune disease, but the cells.
- An autoimmune disease does not attack nutrients such as glucose.