The Body 's Defence Against Infectious Disease

1038 Words5 Pages
Honors Biology Homework: Chapter 24 - Reading Objectives (20 pts.) Name: Hunter Marshall Period: A Innate Defenses 1. Describe and compare the external and internal innate defenses that protect us from microbes and other substances that could invade and harm the body. Answer: The Immune system is the body’s defence against infectious disease Our bodies defend us against pathogens, disease- causing viruses and microorganisms. The human body contains two lines of defence. External barriers and internal defenses both are Innate defenses fully ready to respond before and invader has been encountered. Adaptive defenses are a third line of defense, activated by exposure to specific invaders, the body has physical barriers including, a…show more content…
The lymphatic system consist of a branching network of vessels, numerous lymph nodes, and several other organs.Lymphatic vessels carry lymph a fluid that is similar fluid surrounding body. 3. Describe the general structure and functions of the lymphatic system. Explain how lymph is formed. Answer: The lymphatic system returns tissue fluid to the circulatory system and fights infection. Adaptive defences are the third line of defence, are activated after exposure to specific pathogens, and depended upon lymphocytes that recognize and respond to specific invading pathogens. Adaptive Defenses 4. Explain how T and B cells are formed and how each functions. Answer: The are two types of lymphocytes B cells, which mature in the bone marrow, and T cells, which mature in the thymus, a gland in the chest B and T cells eventually make their way to lymph nodes and other lymphatic organs. There are different types of b cell and t cell. both are lymphocytes, a subclass of white blood cell. the t cells are mainly used in identifying antigens and releasing chemicals which attract macrophages, to destroy the antigen. b cells are used in the production of antibodies. when they encounter a new antigen, plasma cells and
Open Document