Ch. 1 An Overview of the Immune System Flashcards
What is immunity?
the state of protection against foreign pathogens or substances
What is the etymology of the word immunity?
Immunis= exempt
What is the oldest written reference of the “state of being immune?”
Thucydides wrote in 430 BC of the plague of Athens
In what ways did people originally try to avoid the deadly and disfiguring disease smallpox?
Inoculation: plugging nose with cotton dipped in smallpox scabs, wearing underwear of infected children, inhaling dried smallpox scabs.
Variolation: intentional inoculation of dried smallpox scabs into the skin.
When was smallpox eradicated?
1980; it has been 41 years
Summarize the key findings of Louis Pasteur’s vacation-derived findings on fowl cholera. Could you explain the events that led to his declaration of a fowl cholera vaccine?
When inoculating chickens with the fresh cholera he had grown, the chickens died. After returning from vacation, he decided to use the old cholera that had been sitting and found the chickens had gotten sick, but did not die. Later he injected fresh cholera into the chickens who had been exposed and new chickens. All of the new chickens died, but the ones previously exposed lived.
Give three examples of diseases that are rare due to large-scale vaccination programs
- diptheria
- rubella
- pertussis
Summarize the evidence Team Humor had that vaccines worked through serum.
• Serum from immune animals lacking any cells gave naïve animals immunity to diptheria and tetanus. This serum could:
o Neutralize toxins (antitoxin)
o Clump bacteria (agglutinin)
o Lyse bacterial cells (complement)
• In 1930s scientists discover that immunoglobulins (antibodies) are responsible.
o Antiserum could be made from animals previously exposed to pathogens and given to infected patients.
Summarize the evidence Team Phagocytes had that vaccines worked through blood cells.
- Phagocytes were more active in immunized animals (Dr. Elie Metchnikoff)
- WBCs from guinea pigs sensitive to tuberculin and transferred to naïve guinea pigs. They became immune. These cells were lymphocytes. 2 types: T lymphocytes and B lymphocytes.
Summarize the origins of the Iditarod. Why would people go through such trouble to deliver medicine of this type?
Outbreak of diphtheria threatened Nome, Alaska and the nearest medicine (antitoxin) was in Anchorage. A train took the medicine to Nenana, but the only plane had a frozen engine. Largescale race ensued using dog sleds taking more than 20 mushers traveling through a -23 F blizzard to deliver the medicine.
How were Team Humor & Team Phagocytes both correct when it came to how vaccines lead to immunity?
Team Humor: humoral immunity is imparted by B cells (antibodies)
Team Phagocytes: cellular immunity is imparted by T cells.
What can serve as an antigen?
• An antigen is any substance that elicits a response by B or T cells.
o Nonpathogenic/noninfectious materials
o Organic chemicals (ex. Lactose or gluten)
o Newly synthesized compounds not found in nature
o Proteins differing in a single amino acid
What three theories were created to help explain how the immune response to react to very specific antigens?
- Selective Theory
- Instructional Theory
- Clonal Selection Theory
Which theory was the most accurate when describing how the immune response to react to very specific antigens?
Clonal Selection Theory
Selective Theory
o A cell expresses many receptors and antigen binding induces expression of more receptors of that type
o HOWEVER, with a limited number of genes, how could this be possible?
o Evidence showing antigen recognition of molecules never before seen were still recognized.
o Why would our cells make a receptor to something that didn’t exist?
