Located of the brainstem; controls breathing and heartbeat; connects the medulla to the two sides of the cerebellum to help coordinate and integrate movement on each side of side of the body; involved in sleep and dreaming.
Serious symptoms related to the bite of a brown recluse spider include low platelet count, destruction of the red blood cells, blot clots in capillaries, inability to form clots, acute renal failure or kidney damage, coma, and death.
1 Other symptoms include fever, chills, nausea, vomiting, muscle aches and hemolytic anemia (a condition where the red blood cells are destroyed).  People bitten by an unseen spider sometimes blame the brown recluse spider because their bite resembles a brown recluse spider bite.