Introduction to Immunology

Question 1

What is immunology?

Answer 1

study of body’s response against infection (immune system)

Question 2

What does the immune system do?

Answer 2

• protect us from infection through various LINES OF DEFENSE

Question 3

What occurs when the immune system is not working properly?

Answer 3

disease results (autoimmunity, allergy, cancer)

Question 4

What is the nature of an immune response?

Answer 4

beneficial or harmful depending on the nature of the ANTIGEN (when response is beneficial, antigen absence is harmful)

Question 5

What is the effect of the antigen: innocuous substance?

Answer 5

normal: allergy
deficient: no response

Question 6

What is the effect of the antigen: infectious agent?

Answer 6

normal: protective immunity
deficient: recurrent infection

Question 7

What is the effect of the antigen: grafted organ

Answer 7

normal: rejection
deficient: accepted

Question 8

What is the effect of the antigen: self organ?

Answer 8

normal: autoimmunity
deficient: self-tolerance

Question 9

What is the effect of the antigen: tumor?

Answer 9

normal: tumor immunity
deficient: cancer

Question 10

Examples of microbial pathogens?

Answer 10

• bacteria
• fungi
• viruses
• parasite

Question 11

What are infections?

Answer 11

transmitted from people/surfaces

Question 12

What are infectious diseases?

Answer 12

caused by pathogenic microorganisms that spread from the environment or from one person to another causing illness

Question 13

What are the modes of transmission?

Answer 13

• direct contact
• droplet spread
• indirect

Question 14

What are indirect modes of transmission?

Answer 14

airborne (dust or droplets suspended in air)

vehicleborne (for, water, blood, and fomites)

vectorborne (mosquitos, fleas, and ticks)

Question 14

Infectious diseases impact worldwide?

Answer 14

4 major infectious diseases account for “burden of disease” including DALY (disability-adjusted life years)

Question 15

How does economy impact infections and life expectancy?

Answer 15

↓ economic resources = ↑ burden of infectious disease = ↓ like expectancy = ↓ infection control

Question 16

improvements to infectious diseases control?

Answer 16

• use of antibiotics
• clean drinking water
• vaccines

Question 17

What is the chain of infection?

Answer 17

1. portal of entry (mouth, nose, eyes, cuts, respiratory)
2. susceptible host (elderly, infant, immunocompromised)
3. pathogen (bacteria, virus..)
4. reservoir (where pathogen lives - organisms, soil, food, water)
5. portal of exit (respiratory, bodily secretions, feces)
6. mode of transmission

• continuous

Question 18

Strategies to break chain of infection?

Answer 18

• vaccine
• safe food handling
• hygiene
• water treatment/purification
• sewage disposal
• STD control
• reduce reservoir for infectious vectors

Question 19

What are the types of infectious disease?

Answer 19

• endemic
• epidemic
• outbreak
• pandemic

Question 20

What is an endemic?

Answer 20

consistently present throughout a specific region or population
- may fluctuation during seasons)

Question 21

What is an epidemic?

Answer 21

spreads unexpectedly and suddenly across a specific geographical area or population

Question 22

What is an outbreak?

Answer 22

small scale epidemic in a community

Question 23

What is a pandemic?

Answer 23

global scale epidemic

Question 24

What is the balance of health and/or disease?

Answer 24

environment (population, season, region) pathogen host (vaccinated? immunocompromised)

Question 25

What are the 4 general roles of the immune system?

Answer 25

1. BARRIERS: keeps pathogens from entering tissues 2. CELLS: if pathogens enter barrier, detection/detection of invading pathogen 3. CYTOKINES, CHEMOKINES: passes message along to other cells 4. MEMORY: quickly respond to the pathogen and prepares for next time

Question 26

What are the 2 parts of the immune system?

Answer 26

innate immunity (barriers, cells, immune signalling) adaptive immunity (t-cells, b-cells)

Question 27

What are the main immune defences?

Answer 27

1. anatomic barriers 2. immune cells 3. proteins secreted by cells

Question 28

What are anatomical barriers?

Answer 28

- skin - tissues - commensal microbiota can be mechanical (ex. muscles in digestive tract) can be chemical (ex. saliva breaks down food)

Question 29

What shapes the microbiome?

Answer 29

environmental factors (diet, maternal) and genetic

Question 30

What is the break down of blood after centrifuged?

Answer 30

55% plasma <1% Buffy coat has leukocytes (white blood cells) and platelets 45% erythrocytes (red blood cells)

Question 31

What is contained in plasma?

Answer 31

proteins: blood hormones, clotting factors, enzymes, and antibodies (B-cells)

Question 32

How are blood cells derived?

Answer 32

hematopoiesis: hematopoietic stem cell (self-renewing)

Question 33

What are professional phagocytic cells?

Answer 33

- monocytes - macrophages - neutrophils - dendritic cells

Question 34

What are lymphocytes?

Answer 34

- T cells - B cells - NK cells

Question 35

What are the proteins secreted by cells used for immune defenses?

Answer 35

- cytokines (chemical messages made by immune cells) - complement proteins - antibodies (B-cell)

Question 36

What are the types of immunity?

Answer 36

active: own body immune response is activated in response to infection (natural) or vaccine (artificial) passive: immune components are acquired from another individual

Question 37

What passive humoral immunity?

Answer 37

- provided by the transfer of antibodies from a donor - immediate, short-term immunity (months)

Question 38

what is acquired immunity?

Answer 38

immunity developed over lifetime

Question 39

What are natural and artificial passive immunity?

Answer 39

natural: antibodies received fro mother artificial: antibodies from medicine

Question 40

How does natural passive immunity work?

Answer 40

pregnancy: antibodies transferred from mother to fetus vaccination during pregnancy transfers protection to baby after birth: antibodies transmitted via breastmilk newborns develop adaptive immunes after 1 year and are born with innate immunity

Question 41

How does artificial passive immunity work?

Answer 41

IVIG (intravenous immunoglobulin): therapy treatment for patients with antibody deficiencies - plasma extracted from healthy donor and is used to prepare immunoglobulins (antibodies)