Lecture 10

Question 1

What are signs of inflammation?

Answer 1

pain, redness, immobility, swelling (edema), heat

Question 2

What kind of defense response is inflammation?

Answer 2

local defense response
- second line of defense

Question 3

Why is inflammation good?

Answer 3

• destroys injurious agent or limits its effects on the body
• repairs and replaces tissue damaged by the injurious agent

Question 4

Why does pain happen when inflamed? Redness? Swelling? Heat?

Answer 4

• pain: release of certain chemicals
• redness: more blood goes to affected area
• swelling: accumulation of fluids
• heat: increase in blood flow

Question 5

What is acute inflammation?

Answer 5

• signs develop rapidly and last a few days or weeks
• mild and self limiting
• principal defense cells aren’t neutrophil

Question 6

What are examples of acute inflammation?

Answer 6

• sore throat
• cold
• flu
• scratch on the skin

Question 7

What is chronic inflammation?

Answer 7

signs develop more slowly and can last for up to several months or years

Question 8

What are examples of chronic inflammation?

Answer 8

• tuberculosis
• rheumatoid arthritis

Question 9

What happens in early inflammation? Give an example.

Answer 9

microbial structures stimulate toll-like receptors on macrophages, triggering cytokine production
- tumor necrosis factor-alpha (TNF-alpha)

Question 10

What are examples of microbial structures?

Answer 10

• flagellin
• lipopolysaccharides
• bacterial DNA

Question 11

What are acute phase proteins?

Answer 11

• liver synthesizes acute phase proteins in response to TNF-alpha
• C-reactive protein (CRP), mannose-binding lectin, fibrinogen are activated during inflammation
• they induce local and systemic responses, aiding in blood clotting and vasodilation

Question 12

What cells are involved in inflammation? How?

Answer 12

TNF-alpha receptors, producing more TNF-alpha
- amplifies the inflammatory response

Question 13

What happens with excess TNF-alpha?

Answer 13

• can lead to rheumatoid arthritis

Question 14

How do we treat excess TNF-alpha?

Answer 14

monoclonal antibodies

Question 15

What does inflammation activate?

Answer 15

acute-phase proteins by the liver that cause vasodilation and increased permeability of blood vessels

Question 16

What is vasodilation responsible for?

Answer 16

redness and heat associated with inflammation

Question 17

What are examples of vasoactive mediators?

Answer 17

• histamine: (chemical) causes blood vessels to widen, leading to inflammation and allergy symptoms
• kinins: (proteins) promotes inflammation, vasodilation, and pain during immune responses
• prostaglandins: (lipids) cause inflammation, pain, fever by increasing blood flow to affected areas
• leukotrienes: (chemicals) cause inflammation by attracting white blood cells to the site of infection or injury
• cytokines: (proteins) regulate and communicate between cells, coordinating immune and inflammatory responses

Question 18

What is margination?

Answer 18

sticking of phagocytes to blood vessels in response to cytokines at the site of inflammation as the flow of blood gradually decreases

Question 19

What do cytokines do in margination?

Answer 19

alter cellular adhesion molecules on cells, lining blood vessels, causing the phagocytes to stick to the side of inflammation

Question 20

What happens during diapedesis?

Answer 20

where phagocytes squeeze between endothelial cells of blood vessels
- ameboid movement

Question 21

What happens during phagocytosis?

Answer 21

phagocytes began to destroy invading microorganisms

Question 22

When can tissue repair occur?

Answer 22

once all harmful substances are removed and neutralized

Question 23

What is the stroma?

Answer 23

supporting connective tissue that is repaired
- scar tissue will form

Question 24

What is the parenchyma?

Answer 24

functioning part of the tissue that is repaired
- more active in repair

Question 25

What is the most frequent cause of a fever?

Answer 25

infection from bacteria

Question 26

What is the hypothalamus?

Answer 26

body thermostat - 37C

Question 27

How do cytokines affect the hypothalamus?

Answer 27

release prostaglandins that reset the hypothalamus to a higher temperature - body maintains higher temperature until cytokines are eliminated

Question 28

What is crisis?

Answer 28

when the body undergoes the infection, vasodilation, and sweat

Question 29

What is the complement activation?

Answer 29

- working together in a cascade - serum proteins produced by the liver enhance the immune system in destroying microbes

Question 30

What is the classical pathway?

Answer 30

1) antibodies attached to the antigens forming antigen-antibody complex - these complexes bind to and activate C1 2) Activated C1 activates C2 and C4 by splitting each of them into their respective alpha beta complexes 3) C2a and C4b combine and is responsible for splitting C3 into alpha beta

Question 31

What is C3a for?

Answer 31

participates in inflammation

Question 32

What is C3b for?

Answer 32

functions in cytolysis and opsonization

Question 33

Why is the alternative pathway named that?

Answer 33

- doesn't involve antibodies - activated by contact between certain complement proteins and pathogens

Question 34

What is the alternative pathway?

Answer 34

1) C3 combines with complement proteins (factor B, factor D, and factor P) 2) Complement proteins attach to microbial cell surface materials 3) C3 splits into alpha beta - C3a and C3b have the same function as classical pathway

Question 35

What are lectins?

Answer 35

proteins and carbohydrates

Question 36

When is the lectin pathway used?

Answer 36

when macrophages, bacteria, viruses, and other foreign matters go through phagocytosis to release stimulated cytokines to produce lectins

Question 37

What is the lectin pathway?

Answer 37

1) mannose-lectin binds to mannose (carbohydrate) 2) MBL functions as opsonin and enhances phagocytosis, activating C2 and C4 3) C2a and C4b activate C3 and splits it.

Question 38

Why does MBL bind to many pathogens?

Answer 38

they recognize a distinctive pattern of carbohydrates

Question 39

What are the outcomes of complement activation? Give a short description of each.

Answer 39

- cytolysis: activated complement proteins to create a membrane attack complex (MAC) - opsonization: promotes attachment of a phagocyte to a microbe - inflammation: activated complement proteins bind to mast cells, releasing histamine - regulation of complement: regulatory proteins break down complement proteins, minimizing host cell destruction - complement and disease: lack of complement proteins causes susceptibility to infections - evading the complement system: capsules prevent complement activation

Question 40

How do capsules prevent complement activation?

Answer 40

they prevent binding of complement proteins = avoiding opsonization and making it more difficult for immune cells to target and destroy microbes

Question 41

What are interferons and their function?

Answer 41

key signaling molecules that help protect cells from viral infections and activate immune cells to eliminate both viruses and bacteria - alerts neighboring cells and coordinating immune responses to maintain a strong and effective defense system in the body

Question 42

What are IFN-alpha and IFN-beta?

Answer 42

produced by cells in response to viral infections - cause neighboring cells to produce antiviral proteins that inhibit viral replication

Question 43

What is IFN-gamma?

Answer 43

causes neutrophils and macrophages to kill bacteria

Question 44

What is the importance of iron-binding proteins?

Answer 44

regulating availability of iron

Question 45

Why is iron a double-edged sword?

Answer 45

cells need it for functions but bacteria needs it to grow and replicate

Question 46

Where is transferrin found?

Answer 46

found in blood and tissue fluids

Question 47

Where is lactoferrin found?

Answer 47

milk, saliva, mucus

Question 48

Where is ferritin found?

Answer 48

liver, spleen, red bone marrow

Question 49

Where is hemoglobin found?

Answer 49

red blood cells

Question 50

What are siderophores for?

Answer 50

compete with iron-binding proteins

Question 51

What are antimicrobial peptides?

Answer 51

short peptides produced in response to protein and sugar on microbe

Question 52

What is the function of antimicrobial peptides?

Answer 52

- inhibits cell wall synthesis - forms pores in the plasma membrane - acts as first line of defense against invading pathogens

Question 53

Why are antimicrobial peptides effective?

Answer 53

targets broad range of microbes

Question 54

What are other factors of nonspecific immunity?

Answer 54

- genetic resistance - age - observing healthy protocols