Defence mechanisms & immunology

Question 1

Pathway of the lymph system (7 steps)

Answer 1

Lymphatic capillary
Afferent lymphatic vessel
Lymph node
Efferent lymphatic vessel
Lymphatic trunk 
Collecting duct 
Subclavian

Question 2

3 main organs of the lymphatic system

Answer 2

Lymph nodes
Spleen
Thymus

Question 3

7 non specific barriers against infection

Answer 3

Species resistance
Mechanical barriers
Chemical barriers 
Natural killer cells
Inflammation 
Phagocytosis
Fever

Question 4

2nd line of defence

Answer 4

Phagocytosis

Question 5

7 phases of phagocytosis

Answer 5

1)Chemotaxis and phagocyte sticking to microbe
2)Ingestion of microbe by
Phagocyte
3)Engulfing microbe is s phagosome (endocytosis)
4)Fusion of phagosome with lysosomes to form phagolysosome
5)Lysozyme enzymes in lysosomes break down and digest microbe
6)Formation of residual body containing indigestible material
7)Discharge of waste materials

Question 6

7 steps of inflammation

Answer 6

1) Bacteria and other pathogens enter wound
2) platelets release blood clotting proteins at site
3) mast cells mediate vasodilation and vascular constriction.
4) neutrophils secrete factors that kill and degrade pathogens
5) neutrophils and macrophages remove pathogens by phagocytosis
6) Macrophages secrete cytokine hormones that attract immune system cells to site
7) inflammatory response continues until foreign material eliminated and wound repaired

Question 7

Chemotaxis

Answer 7

Movement of phagocyte towards microbe in response to chemicals

Question 8

Phagosome

Answer 8

A vacuole in the phagocyte cell membrane containing a microbe

Question 9

Endocytosis

Answer 9

Engulfing a foreign body into the cell membrane to form a vacuole

Question 10

A phagocyte that has fused with a lysosome

Answer 10

Phagolysosome

Question 11

Neutrophil

Answer 11

A type of immune cell (white blood cell)

Question 12

First line of defence

Answer 12

Skin

Question 13

Third line of defence

Answer 13

Cellular immune response

Humoral immune response

Question 14

Specific immunity

Answer 14

Cellular immune response

Humoral immune response

Question 15

B cell and T cell origin

Answer 15

Red bone marrow

Question 16

Where are B and T cells primarily found

Answer 16

Lymphatic tissues

Question 17

T cell function

Answer 17

Cellular immune response
T cells interact with antigens to destroy them
Helper T cells
Cytotoxic T cells

Question 18

B cell function

Answer 18

Humoral response
B cells interact indirectly with antigen
They produce antibodies that destroy antigen

Question 19

How are Antibodies specific to antigens

Answer 19

Active site on antibodies are specific in shape to antigen

Question 20

What activates a B cell?

Answer 20

Cytokines released by T cells + Binding with an antigen

Question 21

What happens when a helper T cell contacts a displayed antigen?

Answer 21

It multiplies by division and releases cytokines to activate B cells and other chemicals to activate cytotoxic T Cells

Question 22

What activates cytotoxic T cells?

Answer 22

T helper cells release chemicals to activate cytotoxic T cells

Question 23

What happens when cytotoxic T cells are activated?

Answer 23

They divide into memory cells and cytotoxic T cells

Question 24

What happens to activated B cells?

Answer 24

They multiply into other B cells which produce monoclonal antibodies

Question 25

What happens when antibodies combine with antigens?

Answer 25

Complement proteins are activated

Question 26

What 5 ways do antigens destroy pathogens?

Answer 26

``` Oponisation Chemotaxis Lysis Agglutination Neutralisation ```

Question 27

Oponisation

Answer 27

Enhancing phagocytosis of antigens

Question 28

How to antibodies cause chemotaxis towards pathogens?

Answer 28

They attract macrophages and neutrophils

Question 29

Lysis

Answer 29

Rupturing cell membranes (foreign pathogenic cells)

Question 30

Agglutination

Answer 30

Antigens causing pathogens to clump (destroy more at once)

Question 31

Neutralisation

Answer 31

Altering the molecular structure of viruses

Question 32

Primary response

Answer 32

Symptoms Takes longer to destroy pathogen Memory B cells and memory T cells produced

Question 33

Secondary response

Answer 33

Memory cells existing Pathogen destroyed sooner No symptoms (Second exposure to same pathogen)

Question 34

Natural active immunity

Answer 34

Acquired naturally by exposure to live pathogens Immune response causes antibodies to be produced naturally Long term affect

Question 35

Artificially acquired active immunity

Answer 35

Exposure to vaccine (Artificial pathogen -dead/weak) Antibodies produced (active) without symptoms (long term immunity as B memory cells remain in blood and remember how to create antibodies, T cells recognise antigen)

Question 36

Natural passive immunity

Answer 36

Antibodies passed to fetus from mother in breast milk (antibodies given directly=passive) Provides short term immunity

Question 37

Artificial passive immunity

Answer 37

Injection of antibodies | Short term immunity

Question 38

What 4 ways does the placenta function as an immunological barrier

Answer 38

Secreted chemicals that avoid detection by the host Contains lymphocyte suppressor cells that inhibit maternal TC cells Placental cells do not express MHC I complexed (prevents destruction to TC cells) Creates a syncytium (fewer intercellular sites for access of maternal cells)

Question 39

When is the only case that IgG would target fetal cells?

Answer 39

If they were found in maternal circulation

Question 40

What causes the fetus to have a passive immune system?

Answer 40

Placenta allows IgG cells to cross to fetus

Question 41

4 signs of inflammatory response

Answer 41

Redness, pain, swelling, heat

Question 42

Oedema

Answer 42

Swelling

Question 43

6 stages of inflammatory response

Answer 43

1) damaged tissue 2) histamine and kinins 3) vasodilation 4) oedema (swelling) 5) pain receptors activated 6) WBCs activated

Question 44

First and second lines of defence are

Answer 44

Non specific/innate

Question 45

Third line of defence is described as

Answer 45

Specific or adaptive

Question 46

Humoral response involves

Answer 46

Pathogens in bodily fluids

Question 47

Cellular response involves

Answer 47

Infected cells

Question 48

T lymphocyte cells originate in | And move to. To mature

Answer 48

Bone marrow | Thymus gland

Question 49

What two type of cells do T cells divide into

Answer 49

T helper cells | Memory T cells