Inflammation

Question 1

What is inflammation?

Answer 1

An innate immune response to infection or tissue damage that eliminates pathogens, removes damaged tissue, and initiates repair

Question 2

Which arm of the immune system does inflammation belong too?

Answer 2

Innate immunity

Question 3

What triggers an inflammatory response?

Answer 3

Infection, tissue injury, or recognition of pathogens by innate immune cells

Question 4

What are the main goals of inflammation?

Answer 4

Pathogen elimination, containment of infection, and initiation of tissue repair

Question 5

What are the 4 classical signs of inflammation?

Answer 5

1. Calor (heat)
2. Dolor (pain)
3. Rubor (redness)
4. Tumor (swelling)

Question 6

What causes redness and heat during inflammation?

Answer 6

Increased blood flow due to vasodilation

Question 7

What causes swelling during inflammation?

Answer 7

Increased vascular permeability allowing fluid to enter tissues.

Question 8

What causes pain during inflammation?

Answer 8

Pressure from swelling and sensitisation of nerve endings by inflammatory mediators

Question 9

What are cytokines?

Answer 9

Small signalling proteins released by immune cells that regulate immune and inflammatory responses

Question 10

Which cytokines act as endogenous pyrogens?

Answer 10

TNF-α, IL-1 (and IL-6)

Question 11

How do cytokines cause fever?

Answer 11

They induce prostaglandin E2 production in the hypothalamus, raising body temperature.

Question 12

Why is fever beneficial during infection?

Answer 12

It inhibits bacterial growth and enhances adaptive immune responses

Question 13

How does the body conserve heat during fever?

Answer 13

Vasoconstriction reduces heat loss

Question 14

Which cells usually initiate inflammation in tissues?

Answer 14

Macrophages (and dendritic cells)

Question 15

How do macrophages recognise pathogens?

Answer 15

Through pattern recognition receptors (PRRs)

Question 16

What happens when macrophages recognise a pathogen?

Answer 16

They release cytokines and chemokines that initiate inflammation

Question 17

What is chemotaxis?

Answer 17

Directed movement of immune cells toward increasing concentrations of chemokines

Question 18

Which immune cells are recruited first to sites of inflammation?

Answer 18

Neutrophils

Question 19

What is extravasation?

Answer 19

The movement of leukocytes from the bloodstream into infected tissues

Question 20

What is phagocytosis?

Answer 20

The engulfment and intracellular destruction of pathogens by phagocytes

Question 21

List the key steps of phagocytosis?

Answer 21

1. Recognition
2. Engulfment (phagosome formation)
3. Phagolysosome formation
4. Killing and digestion
5. Antigen presentation

Question 22

What is a phagolysosome?

Answer 22

A vesicle formed by fusion of a phagosome with a lysosome, where pathogens are destroyed

Question 23

What happens to antigenic peptides after phagocytosis?

Answer 23

They are loaded onto MHC class II molecules

Question 24

What is antigen presentation?

Answer 24

Display of processed antigenic peptides on MHC molecules for recognition by T cells

Question 25

Which MHC class presents antigen from phagocytosed pathogens?

Answer 25

MHC class II

Question 26

Which T cells recognise MHC class- II presented antigen?

Answer 26

CD4⁺ helper T cells

Question 27

Name the 3 main antigen presenting cells (APCs)?

Answer 27

1. Dendritic cells 2. Macrophages 3. B cells

Question 28

What are PRRs?

Answer 28

Germline-encoded receptors that recognise pathogen-associated molecular patterns (PAMPs)

Question 29

What are PAMPs?

Answer 29

Conserved molecular structures found on pathogens but not host cells

Question 30

Why are PRRs important for innate immunity?

Answer 30

They allow rapid, non-specific recognition of pathogens

Question 31

What are Toll-like receptors?

Answer 31

A family of PRRs that detect microbial components and initiate inflammatory signalling

Question 32

Where are TLRs located in the cell?

Answer 32

On the cell surface and on endosomal membranes

Question 33

Which TLR recognises LPS from Gram-negative bacteria?

Answer 33

TLR4

Question 34

Which TLRs recognise Gram-positive bacterial components?

Answer 34

TLR1/TLR2 heterodimer

Question 35

Which ligands are recognised by endosomal TLRs?

Answer 35

Viral ssRNA, dsRNA, and bacterial CpG DNA

Question 36

What intracellular domain is shared by TLRs?

Answer 36

TIR (Toll–IL-1 receptor) domain.

Question 37

What adaptor molecule is used by most TLRs?

Answer 37

MyD88

Question 38

What is the outcome of TLR signalling?

Answer 38

Activation of inflammatory gene transcription and cytokine production

Question 39

What role do dendritic cells play in adaptive immunity?

Answer 39

They activate naiive T cells

Question 40

Where do dendritic cells capture antigen?

Answer 40

In peripheral tissues (e.g. skin)

Question 41

Where do dendritic cells activate naiive T cells?

Answer 41

In lymph nodes

Question 42

What is opsonisation?

Answer 42

Coating of pathogens with antibodies or complement to enhance phagocytosis

Question 43

Which receptors on phagocytes recognise opsonised pathogens?

Answer 43

Fc receptors and complement receptors

Question 44

Why does opsonisation increase bacterial killing?

Answer 44

It enhances uptake and triggers lysosome-phagosome fusion

Question 45

How do some bacteria evade phagocytosis?

Answer 45

By resisting uptake or surviving inside phagocytes

Question 46

How does adaptive immunity overcome bacterial evasion?

Answer 46

Through antibody- mediated opsonisation