Answer: Release of histamine and other chemicals that increase blood flow and vascular permeability.
- A Direct mechanical damage inflicted on tissue by the invading pathogen itself over time
- B Release of histamine and other chemicals that increase blood flow and vascular permeability
- C Activation of cytotoxic T cells that are circulating near the wound site
- D Formation of new antibodies by plasma cells residing within nearby lymph nodes
Correct answer: B. Release of histamine and other chemicals that increase blood flow and vascular permeability
Explanation: Inflammation is triggered by damaged cells releasing histamine, prostaglandins, and cytokines. These cause vasodilation (increased blood flow = redness, heat) and increased vascular permeability (fluid leaks = swelling), also activating pain receptors.
An antibody is Y-shaped, with two identical antigen-binding sites at the tips of the variable regions - each shaped to recognise one specific antigen - while the constant (Fc) region at the base is recognised by immune cells to trigger further responses.
Concept context
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET.