Immunity

Question 1

Immunity

Answer 1

the ability of an organism to resist an infection or toxin

Question 2

Features of an effective immune system

Answer 2

Fast/rapid, should not harm the host, response should be innate, must be an appropriate response for the pathogen

Question 3

Active Immunity

Answer 3

Body produces antibodies because of an immune response to a foreign antigen. Results in production of B memory cells. .

Question 4

Natural active immunity

Answer 4

Gained due to the infection of a pathogen (e.g. Getting a cold)
Memory T cells remember foreign antigen for long periods of time
Memory B cells will rapidly divide into plasma cells to produce many antibodies

Question 5

Artificial active immunity

Answer 5

Via vaccination
Antigens are artificially introduced, usually as an attenuated virus (i.e. An inactive, weaker version of virus), or only parts of the pathogen that has the antigen
Purpose is to generate B memory cells which will then divide into plasma cells to produce antibodies.

Question 6

Passive Immunity

Answer 6

Short lives as your body is being injected with antibodies, thus B memory cells will not be produced

Question 7

Natural passive immunity

Answer 7

Antibodies are not produced in the body but from an outside, natural source (e.g. breastmilk)

Question 8

Artificial passive immunity

Answer 8

Antibodies are given as an injection (e.g. snake anti-venom)

Question 9

Herd Immunity

Answer 9

Indirect protection from infection. Protection is created by the presence of immune individuals in population, gives those who are unvaccinated from the disease protection.

Highly beneficial to infants and HIV patients.
Infants have immature immune systems which cannot produce enough B and memory T cells which may reduce their ability to be vaccinated.

Question 10

Monoclonal Antibodies in Treating Cancer

Answer 10

Antibodies can be designed that target antigens on cancer cells, and then multiple copies of these antibodies can be produced in a lab
MABs used in cancer treatment can be divided into two groups;
1. Naked MAbs: which do not have any other molecules joined to them
2. Conjugated MAbs: have additional groups attached

Question 11

Naked MAbs uses

Answer 11

stopping growth of new blood vessels to cancer, signalling immune cells to attack cancers, blocking signals for cell division

Question 12

Conjugated MAbs uses

Answer 12

delivering anticancer drugs to cancer cells, delivering radioisotopes to cancer cells

Question 13

Hypersensitivity

Answer 13

occurs when the immune system is activated when it doesn’t need to be

Question 14

Type 1 hypersensitivity

Allergic response

Answer 14

Abnormal reaction to a normally harmless substance

Question 15

First Exposure

Answer 15

Allergen - (i.e. An antigen that causes the immune system to act in an abnormal way) lodges in mucus membranes and is recognised as foreign by immune system

Immune response occurs and plasma cells produce vast quantities of IgE

IgE detect and travel to a special white blood cells known as mast cells (does this by identifying the Fc portion of the cell)

Question 16

Second Exposure

Answer 16

Allergen travels and binds to the specific IgE antibodies that are already bound to mast cells

This causes mast cells to release vast quantities of histamine which has several effects/symptoms on the body (e.g. redness and swelling, watery eyes, sneezing)

Question 17

Type 2 hypersensitivity

Autoimmune Disease

Answer 17

When either the humoral or cell mediated immune response is activated against the self-cells of the host, often leading to damage of the affected tissues/organs.
Examples include: type 1 diabetes, MS

Question 18

Immunodeficiency

Answer 18

Whereby functioning of innate and/or adaptive immune response is impaired
Leads to increased vulnerability of infection

Question 19

HIV/AIDS

Answer 19

Virus that specifically invades and destroys T helper cells, thus leads to progressive impairment of the immune system given the major roles T helper cells play (i.e. clonal expansion of B cells and release of cytokines to activate cytotoxic T cells)

People who are HIV positive, if left untreated, will exhibit progressive loss of T helper cells > this in turn results in the immune response being unable to fight pathogens causing HIV to be referred to as AIDS

Question 20

Pathogens

Answer 20

anything that can cause disease. Impairs normal functioning of its host

Question 21

Viruses

Answer 21

Obligate intracellular parasites, non-cellular and non-living.
Cannot independently reproduce - needs to infect a cell and use that cells

Question 22

Bacteria

Answer 22

Causes disease, cellular agents, can reproduce independently via binary fission.
Natural flora is beneficial because they compete with pathogenic bacteria for resources

Question 23

Fungi

Answer 23

Eukaryotes, have a chitin cell wall, acts as infectious agents

Question 24

Prions

Answer 24

Misfolded proteins, converts normal prion proteins into an abnormal form, build-up in neurons, causing neuron to burst

Question 25

Antigens

Answer 25

compounds, usually proteins, that can trigger the immune system to respond in various ways, found on the outside

Question 26

B cells

Answer 26

mature in bone marrow then to lymph nodes

Question 27

T cells

Answer 27

produce in bone mature, mature in thymus gland then travels to lymph nodes