Exam 1 Lecture 4

Question 1

Bacteria vs Immune Response

Answer 1

Immune system usually wins most of the time

Question 2

True or false: Most of the bacteria that live on our planet are capable of beating the human immune system

Answer 2

False; most have evolved to live in other niches

Question 3

What traits to some bacteria have that they can use to get around our immune system?

Answer 3

1. Virulence factors 2. Host defenses previously disrupted which make it easier for bacteria to cause infection

Question 4

There is a ______ of human and pathogens

Answer 4

co-evolution

Question 5

Disease = (2 things)

Answer 5

1. Lack of tolerance AND 2. Lack of Resistance

Question 6

Resistance

Answer 6

The ability to eliminate a pathogen once it has entered our bodies

Question 7

Tolerance

Answer 7

Bacteria can be in the host but not cause infection

Question 8

True or false: we get sick every time a bacteria enters our bodies

Answer 8

False; normally, no. ex) normal microbiota

Question 9

2 major types of immunity

Answer 9

Innate and adaptive

Question 10

Innate immunity

Answer 10

first line of defense rapid responses to a broad range of microbes germline encoded receptors and responses early warning and defense system

Question 11

Adaptive Immunity

Answer 11

Primary response takes time Targeted to specific microbes Clonally rearranged receptors Provides immunologic memory

Question 12

External defenses

Answer 12

Part of innate immunity Physical and chemical barriers Mucous membranes

Question 13

Internal defenses

Answer 13

Part of innate immunity: complement; phagocytic cells; pattern recognition receptors; inflammatory response

Question 14

Innate immunity time scale:

Answer 14

Hours

Question 15

Adaptive immunity examples

Answer 15

Humoral response (antibodies) Cell-mediated response (T cells)

Question 16

Adaptive immunity time scale

Answer 16

Days

Question 17

Examples of physical and chemical barriers

Answer 17

Skin, tears, saliva, respiratory (mucus and cilia trap and remove organisms)

Question 18

How can microbiota protect us?

Answer 18

They compete with pathogens for nutrients, produce antimicrobials, and influence the immune system

Question 19

If pathogens manage to breach initial external defenses, where might they end up?

Answer 19

gastrointestinal tract mucosa or respiratory tract

Question 20

Stomach

Answer 20

contains acidic pH which can kill many microorganisms

Question 21

Helicobacter pylori

Answer 21

adapted to acidic pH in stomach, cleaves urea to form NH3 which, as a base, acts as a buffer to resist harsh stomach acid

Question 22

Mucus

Answer 22

viscous; contains antimicrobial molecules

Question 23

How many layers of mucus are found in the GI tract?

Answer 23

2: outer and inner mucus layer

Question 24

True or false: the inner mucus layer is essentially sterile

Answer 24

True

Question 25

Cell surface mucins prevent:

Answer 25

pathogen binding

Question 26

The ___ and ___ influence components of the mucus barrier

Answer 26

Microbiota; immune system

Question 27

What do Goblet cells secrete?

Answer 27

Mucins

Question 28

What do Paneth cells secrete?

Answer 28

Antimicrobial defensins and other proteins

Question 29

What is the function of M-cells?

Answer 29

They sample contents of the stomach and deliver antigens from the gut lumen to the immune system.

Question 30

Two parts of the Innate Immune System?

Answer 30

External (physical, chemical and mucous) and Internal Defenses (Complement, Phagocytes, PRRs and Inflammatory Response

Question 31

What is the Complement System made up of?

Answer 31

It is a family of proteins present in blood and tissues that contains enzymes, receptors, and regulatory proteins

Question 32

What does the Complement System do when activated and the 3 outcomes of activation?

Answer 32

It links the innate and adaptive systems.

1. Inflammation and Opsonization
2. Opsonization
3. Pathogen Lysis (Membrane Attack Complex)

Question 33

3 pathways of complement activation?

Answer 33

1. Classical
2. Lectin
3. Alternative