6) Determine whether each of the following scenarios are part of the First, Second, or Third line of defense: (4) SCENARIO
LINE OF DEFENSE

Macrophages move through tissues and destroy any pathogens that they encounter.
First line of defense
Bacteria are destroyed by hydrochloric acid in the stomach after being ingested.

A phagocytic leukocyte digests a pathogen and presents the respective antigens on the surface of its membrane.

Antibodies in the bloodstream slow down a pathogen that has previously been encountered by white blood cells and mark it for destruction.

T-cells analyze pathogens after they have been broken down and recruit B-cells to help identify the foreign particles.