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.
The most electric place in the world: Venezuelan lake is hit by lightning THOUSANDS of times an hour. Venezuela's eternal lightning storm has captivated tourists and locals for generations. Where the Catatumbo River meets Lake Maracaibo, 260 storm days each year cause 28 lightning strikes to hit the lake each minute. The unique atmospheric phenomenon generates 1.2 million lightning strikes each year and is visible from almost 250 miles (400km) away. Scroll down for video.