Ch. 18-Immune Today Your DCP & CE for the Catalase Lab are due….______ Write this down: 1. Download the DCP/CE Rubric 2. the end of your GRADED Design Lab 3. Then, insert your revised procedure & explain that it’s revised b/c … (did you not have enough data, etc) 4. Then, continue with your DCP & CE sections Get ‘Er Done!

18 Immunology: Gene Expression and Natural Defense Systems

18.1 What Are the Major Defense Systems of Animals? REVIEW! What’s a pathogen? Self/non-self?

Photo 18.1 Bacterial plaque in a human mouth. SEM.

18.1 What Are the Major Defense Systems of Animals? Two types of defense mechanisms:

Photo 18.2 Human skin: Thick surface layer of keratin forms a barrier to pathogens. LM.

Figure 18.1 The Human Lymphatic System

Figure 18.2 Blood Cells (Part 1)

Figure 18.2 Blood Cells (Part 2)

Figure 18.2 Blood Cells (Part 3)

Photo 18.4 Two white blood cells (monocyte, left; neutrophil, right) among red blood cells. LM.

Photo 18.5 Section through a macrophage. TEM.

Photo 18.6 Polymorphonuclear neutrophil ingesting bacteria by phagocytosis. TEM.

18.1 What Are the Major Defense Systems of Animals? T cells:

Photo 18.7 Lymphocyte (T or B cell) in normal human blood. LM. Wright stain.

18.1 What Are the Major Defense Systems of Animals? Many proteins involved in cell–cell interactions of defense system:

Table 18.1 (Part 1)

Table 18.1 (Part 2)

18.2 What Are the Characteristics of the Nonspecific Defenses? Phagocytes

Figure 18.3 A Phagocyte and Its Bacterial Prey

Figure 18.4 Interactions of Cells and Chemical Signals Results in Inflammation Blood capillary Skin Bacteria introduced by splinter Splinter Mast cell Damaged tissues attract mast cells which release histamine, which diffuses into the capillaries.

Figure 18.4 Interactions of Cells and Chemical Signals Results in Inflammation Histamine causes the capillaries to dilate and become leaky; complement proteins leave the capillaries and attract phagocytes. Blood plasma and phagocytes move into infected tissue from the capillaries. Complement proteins Phagocyte

Figure 18.4 Interactions of Cells and Chemical Signals Results in Inflammation Dead phagocyte Phagocytes engulf bacteria and dead cells. Histamine and complement signaling cease; phagocytes are no longer attracted. Signaling molecules stimulate endothelial cell division, healing the wound.

18.3 How Does Specific Immunity Develop? The specific immune system has 4 key traits:

11.1.6Explain the principle of vaccination.

Discuss the benefits and dangers of vaccination.

BenefitDanger Possible total elimination of disease. (has occurred w/smallpox; many believe it’s possible for polio and measles) Before 1999, many vacc contained thimerosal (Hg-based preservative). Hg = neurotoxin, infants & young children particularly susceptible Decrease in spread of epidemics (localized infections) and pandemics (worldwide infections). Increased INTL travel made it more imp! Infection begun on 1 side of world could be on other side of world in less than a day. Perception exists that multiple vaccs given to kids in relatively short pd of time may overload their immune system. Preventative medicine’s typically most cost-effective approach to healthcare. Cost of vacc programs small compared to costs of treating many preventable diseases. Anecdotal evidence suggested that MMR vacc may have link to onset of autism. Clinical studies haven’t supported it. Each vacc’d individual benefits b/c full symptoms of disease don’t have to be experienced in order to gain immunity. Cases reported of vacc leading to allergic reactions and autoimmune responses

18.3 How Does Specific Immunity Develop? Specific immune system has two types of responses: