Test Bank I Clicker Questions of Chapter 12 The Lymphatic System I Essentials of Human Anatomy and Physiology 11e I Elaine N. Marieb

The text discusses the lymphatic system and immune response. Some key points: • Any substance that can provoke an immune response is called an antigen. • The thymus gland is larger in younger people and found in the anterior thorax. • Cytokines are proteins secreted by macrophages that are important in the immune response. • Antibodies are not part of the first line of defense against pathogens. • When exposed to the wrong blood type for the first time, a person's antibody response takes about 10 days to peak. • The spleen filters and cleanses the blood and is a site of lymphatic proliferation. • Interferons bind to healthy cells and prevent viruses from multiplying within them. • Pathogens are harmful or disease-causing organisms. • Multiple sclerosis is an autoimmune disease that destroys the myelin sheaths of the central nervous system. • Helper T cells activate B cells. • Lymphoid tissue like tonsils and Peyer's patches protect the upper respiratory and digestive tracts. • Cytokines are chemicals released by T cells and macrophages during an immune response.