Learning Objectives By the end of this section, you will be able to: Immunodeficiencies are inherited (primary) or acquired (secondary) disorders in which elements of host immune defenses are either absent or functionally defective. In developed countries, most immunodeficiencies are…
Learning Objectives By the end of this section, you will be able to: A graft is the transplantation of an organ or tissue to a different location, with the goal of replacing a missing or damaged organ or tissue. Grafts are typically moved without…
Learning Objectives By the end of this section, you will be able to: In 1970, artist Walt Kelly developed a poster promoting Earth Day, featuring a character from Pogo, his daily newspaper comic strip. In the poster, Pogo looks out across…
Learning Objectives By the end of this section, you will be able to: Clinical Focus Part 1 Kerry, a 40-year-old airline pilot, has made an appointment with her primary care physician to discuss a rash that develops whenever she spends…
Figure 19.1 Bee stings and other allergens can cause life-threatening, systemic allergic reactions. Sensitive individuals may need to carry an epinephrine auto-injector (e.g., EpiPen) in case of a sting. A bee-sting allergy is an example of an immune response that is harmful to the host…
17.1 Physical Defenses 17.2 Chemical Defenses 17.3 Cellular Defenses 17.4 Pathogen Recognition and Phagocytosis 17.5 Inflammation and Fever
Learning Objectives By the end of this section, you will be able to: The inflammatory response, or inflammation, is triggered by a cascade of chemical mediators and cellular responses that may occur when cells are damaged and stressed or when pathogens…
Learning Objectives By the end of this section, you will be able to: Several of the cell types discussed in the previous section can be described as phagocytes—cells whose main function is to seek, ingest, and kill pathogens. This process,…
Learning Objectives By the end of this section, you will be able to: In the previous section, we discussed some of the chemical mediators found in plasma, the fluid portion of blood. The nonfluid portion of blood consists of various…
Learning Objectives By the end of this section, you will be able to: In addition to physical defenses, the innate nonspecific immune system uses a number of chemical mediators that inhibit microbial invaders. The term “chemical mediators” encompasses a wide array of…