Hypersensitivity is the immune system doing its job too hard, or against the wrong target. The Gell and Coombs scheme sorts these damaging reactions into four types. It sorts them by what carries the reaction and how fast it strikes. Pick a type, then run the clock and watch the mechanism assemble itself.
Pick a typestage 1 of 4
Press Play. The clock runs, and the mechanism builds itself.
The four clocks, side by sideone shared time axis
Four ways a defense turns on youpick a type, then press Play
0 secsince the antigen arrived
0
Mediator—
Onset—
Complement—
Memory aid, ACID. Type 1 is Anaphylactic. Type 2 is Cytotoxic. Type 3 is Immune-complex. Type 4 is Delayed. The first three are antibody work. The fourth is T-cell work.