1 An ad hoc network is a local area network (LAN) that is built spontaneously as devices connect. 2  Ad hoc testing is an informal and improvisational approach to assessing the viability of a product. 3  Ad hoc analysis is a business intelligence process designed to answer a single, specific business question.
The circulatory system and immune system serve the same, yet complementary purpose, to keep the entire body alive. The circulatory system does this by delivering oxygen from the lungs to every organ and cell in the body. The immune system does this by consuming foreign substances before they can damage the body. The connection between the circulatory system and immune system lies in the fact that the immune system travels through the entire body, inside the circulatory system. The circulatory system has three major components: the heart, the lungs, and blood vessels.
The lymphatic system and its vessels do not form a closed circulatory system. It begins with small lymphatic vessels (lymph capillaries) in the body tissues, and continues with successively larger lymphatic vessels (collectors and trunks), which ultimately connect to the venous part of the blood circulatory system.