A cellular component of the innate defenses includes

A. Swelling:Swelling, or edema, is a classic cardinal sign of inflammation. It occurs due to increased vascular permeability, which allows fluid, proteins, and immune cells to accumulate in the affected tissue, contributing to the inflammatory response.

B. All are signs of inflammation:All the listed options-swelling, heat, pain, and redness-are classic cardinal signs of inflammation. Therefore, it is not correct to say that any one of them is absent; collectively, they define the inflammatory process.

C. Heat:Heat at the site of inflammation results from increased blood flow (hyperemia) due to vasodilation. It is one of the four primary cardinal signs and reflects the body’s attempt to deliver immune cells and proteins to the affected area.

D. Pain:Pain arises from the release of chemical mediators like prostaglandins and bradykinin that stimulate nerve endings. It signals tissue injury and serves as an alert to prevent further damage.

E. Redness:Redness, or erythema, is caused by increased blood flow to the affected area as part of the vasodilation response. It is a hallmark feature of inflammation and helps identify the affected site visually.

A. Self-antigens:Autoimmune diseases occur when the immune system mistakenly recognizes the body’s own proteins, or self-antigens, as foreign. This leads to an immune response against the body’s own tissues, causing inflammation and tissue damage.

B. Self-complement proteins:Complement proteins are part of the immune system that help destroy pathogens. Autoimmunity involves targeting self-antigens, not complement proteins, although complement may be involved secondarily in tissue damage.

C. Self-antibodies:Antibodies are produced by B cells. In autoimmune diseases, antibodies may target self-antigens, but the primary issue is the immune system failing to recognize self-antigens, not the antibodies themselves.

D. Self-immunoglobulins:Immunoglobulins are antibodies; autoimmunity involves antibodies targeting self-antigens, not the body’s own immunoglobulins. Self-immunoglobulins are not the trigger of autoimmune disorders.

E. Self-interleukins:Interleukins are signaling molecules for immune communication. Autoimmune diseases are not caused by the immune system attacking interleukins, but rather by a failure to distinguish self-antigens from foreign antigens.