Studies on immune responses in afferent and efferent lymph of lymph nodes draining the tissues have contributed to the concept that primary immune responses are generated in the lymph nodes with a delay before antigen-specific effector cells arrive at the affected tissue.
Lightning strikes the ground approximately 25 million times each year in the U.S. According to the NWS, the chance of an individual in the U.S. being killed or injured during a given year is one in 240,000. Assuming an average life-span of 80 years, a person's odds over their lifetime becomes one in 3000.
RIDERS ON THE STORM: HOW PLANES ARE HIT BY LIGHTNING AT LEAST ONCE A YEAR... Although it may sound a terrifying prospect, commercial aircraft around the world are bombarded with bolts of lightning every single day. According to experts, the in an average year any given airliner can expect to be struck at least once on its travels.