Topic 1

Question 1

What are the 4 general types of pathogens

Answer 1

viruses, fungus, parasite, bacterium

Question 2

What are the basic characteristics of immune responses

Answer 2

• most invertebrates can clear an infection, but can be infected again (no immune memory)
• not all responses are successful - some can lead to death or disease
• can result in the clearing of infecting pathogens
• successful immunity leads to immune memory

Question 3

What is immune memory

Answer 3

when the immune system has already dealed with a disease and therefore is more prepared for further infection and has faster elimination then first time

Question 4

What is variolation?

Answer 4

used in China which was used to immunize people against smallpox, where a dried version of smallpox was blown into the nasal passage

Question 5

What were Edward Jenner’s observations

Answer 5

• noticed that english milkmaids got cowpox but not smallpox and it was less deadly with a lower portion of mortality
• Jenner used cow pox variolation to prevent smallpox infections

Question 6

What are the three types of vaccines

Answer 6

• Attenuated: living but weak virus
• Inactivated: killed whole pathogen
• Subunit: parts or components of pathogen

Question 7

What is immune priming?

Answer 7

large amounts of vaccine which leads to immune memory that protects when the vaccinated encounter the infecting pathogen

Question 8

What are some risks with vaccinations

Answer 8

Can cause allergic responses (anaphylaxis), which can also be caused by vaccine quality or handling errors

Question 9

What is Reproduction ratio?

Answer 9

of new infections caused by each infected person also known as transmissibility

Question 10

How can we differentiate if a infection is a epidemic or not?

Answer 10

• if reproduction ratio is less than 1 - not an epidemic as infection will slowly die out
• if reproduction ratio is greater than 1 - then epidemic infection will spread in the population

Question 11

What is herd immunity

Answer 11

proportion of a population that needs to be immune to prevent pathogen spread, based upon the reproduction ratio

Question 12

What are some examples of viral entry routes

Answer 12

• respiratory
• oral - fecal transmission
• sexually
• needles
• through blood

Question 13

What are some physical and chemical barriers of our body?

Answer 13

• mucous and mucous membranes
• acid in sweat (pH 4.5 - 6)
• acid in stomach (pH 2)
• anti-bacterial proteins and zinc in semen
• competition from commensal bacteria in gut and genital tract
• coughing
• cilia in respiratory trap foreign material

Question 14

Mucus characteristics?

Answer 14

• mucous membranes cover 400 m2, while skin only covers 2m2
• lines the GI, respiratory and genitourinary tracts
• thin, permeable barriers
• gas exchange, food absorption, reproduction

Question 15

What are goblet cells

Answer 15

secrete mucus - trap microbes

Question 16

What is the ciliary escalator

Answer 16

• ciliated epithelial cells in trachea and nasopharynx, cilia push bacterial cells back up
• bacteria trapped by mucous and coughed out or swallowed and killed by stomach acid

Question 17

What is normal microbial flora

Answer 17

• biological barrier to infection
• present on all body surfaces exposed to the environment
• area of higher moistures have higher normal flora

Question 18

How does normal flora prevent infection

Answer 18

Microbial antagonism: as they already inhabitat our bodies, through habitat and competition for resources, this limits vacancy for pathogens

Question 19

What are chemical barriers

Answer 19

enzymes that degrade microbial cell walls in saliva and anti-microbial peptides (AMPs)
- can punch holes in microbe membranes

Question 20

What are AMPs also known as?

Answer 20

defensins

Question 21

What is the function of the spleen in the lymphatic system

Answer 21

screens the blood

Question 22

What is the function of lymph nodes

Answer 22

screens the bodies tissues