UNIT 4 7B: Second Line of defence

Question 1

Inflammatory response

Answer 1

heat, pain, redness, swelling and loss of function as part of the innate immune response to harmful stimuli

Question 2

Mast Cell

Answer 2

White blood cell involved in inflammatory response, releasing histamine, triggering inflammation

Question 3

Histamine

Answer 3

Compound released by cells to start an inflammatory response

Question 4

Macrophage

Answer 4

White blood cell that carries out phagocytosis and may act as an antigen-presenting cell,
releases cytokines to attract more immune cells to the area of infection

Question 5

Cytokines

Answer 5

Compounds released by cells as chemical signals to other cells

Question 6

Neutrophil

Answer 6

White blood cell that carries out phagocytosis and kills pathogens with defensins

Question 7

Dendritic cell

Answer 7

White blood cell with many folds in its membrane, carries out phagocytosis and acts as antigen-presenting cell to the adaptive immune system

Question 8

Natural Killer Cell

Answer 8

Part of the innate/non specific response (2nd line of defence), that recognises damaged or missing MHC 1 markers on a eukaryotic (host) cell
Releases perforin

Question 9

Perforin

Answer 9

A protein that kills cells by making holes in their plasma membranes

Question 10

Eosinophil

Answer 10

White blood cell that targets parasites

Question 11

Phagocytosis

Answer 11

A type of endocytosis in which a solid substance enters a cell via vesicle mediated transport

Question 12

Phagosome

Answer 12

A vesicle that engulfs a pathogen during phagocytosis

Question 13

Antigen-presenting cell

Answer 13

A specific type of white blood cell that uses phagocytosis to engulf a pathogen

Question 14

Apoptosis

Answer 14

Death and disintegration of a cell through a controlled process

Question 15

Lysis

Answer 15

Breakdown of the cell membrane

Question 16

Description/function of complement proteins

Answer 16

-Circulate in the blood

-Can cause lysis by puncturing the pathogen’s plasma membrane

-Coat pathogens to make them more identifiable for phagocytes and to reduce the pathogen’s mobility

Question 17

Description of Cytokines

Answer 17

Signalling molecule of the immune system

Released by immune cells and acts on other specific immune cells (lymphocytes)
to activate further adaptive immune responses

Question 18

Examples of Cytokines

Answer 18

Interleukins and interferons

Question 19

Interferon

Answer 19

A type of cytokine released by an infected host cell that defends against further viral infections

Attracts NK cells to assist in killing virus-infected host cells

Question 20

Histamine

Answer 20

A signalling molecules released by mast cells that initiates the inflammatory response

Question 21

Vasodilation

Answer 21

The widening of a blood vessel (especially capilalries), to increase blood flow

Question 22

Key components of the inflammatory response (CCMMVN)

Answer 22

-Cytokines
-Complement proteins
-Mast cells
-Macrophages
-Vasodilation
-Neutrophils

Question 23

Fever

Answer 23

A rise in body temperature caused by infection, can be caused by cytokines from the inflammatory response

Question 24

How is an increase in body temperature during vasodilation beneficial to the immune response

Answer 24

Most bacteria and viruses prefer a lower body temperature in order to replicate more efficiently, while the immune cells perform better at slightly higher temperatures

Question 25

Key steps of the inflammatory response

Answer 25

1. Mast cells release histamine 2. Histamine induces vasodilation, resulting in an increase in blood vessel permeability, blood flow, heat, redness and swelling 3.Phagocytes(such as neutrophils, macrophages) leave the blood and enter the infected tissue 4. phagocytes are attracted by histamines and engulf and destroy the pathogen 5. Macrophages secrete interleukins, which leads to fever

Question 26

Key steps of phagocytosis

Answer 26

1. Phagocyte engulfs a pathogen via endocytosis 2. Vesicle surrounding the pathogen forms a phagosome 3.Lysosomes containing lysozyme attach to the phagosome and release their content to digest the pathogen 4. Debris is released via exocytosis and antigens may be presented on an MHC 2 markerif the phagocyte is acting as an APC

Question 27

Which phagocyte is first to the site of infection

Answer 27

Neutrophils

Question 28

Aims of the inflammatory response

Answer 28

to destroy the cause and products of an infection to confine the infection to a small area To increase the rate at which damaged cells are repaired or replaced

Question 29

What is pus composed of

Answer 29

living and dead white blood cells and pathogens

Question 30

Similarities between natural killer cells and cytotoxic T cells

Answer 30

Both target: Virus infected host cells transplanted tissue/organs both release perforin which punctures holes in infected cell, lysing the cell