Lymph in the lymph vessels eventually reaches a lymph node -- there are about 100 nodes scattered throughout the body. Lymph nodes filter the lymph and also contain large numbers of white blood cells (a big part of the immune system), which remove foreign cells and debris from the lymph.When you get certain infections, the lymph nodes swell with billions of white blood cells working to clear the foreign cells causing the infection.ymph nodes filter the lymph and also contain large numbers of white blood cells (a big part of the immune system), which remove foreign cells and debris from the lymph. When you get certain infections, the lymph nodes swell with billions of white blood cells working to clear the foreign cells causing the infection.
Yellowstone: Annual Weather Averages. July is the hottest month in Yellowstone with an average temperature of 24Â°C (75Â°F) and the coldest is January at -2Â°C (28Â°F) .ellowstone: Annual Weather Averages. July is the hottest month in Yellowstone with an average temperature of 24Â°C (75Â°F) and the coldest is January at -2Â°C (28Â°F) .
NPS / Neal Herbert. Since most of the park lies at an elevation of 6,000 feet above sea level or higher, unpredictability characterizes Yellowstone's weather. Expect big temperature swings, rain, or snow during every month of the year. No matter when you visit, bring a warm jacket, rain gear, and lots of layers.