Immunology

Question 1

Transmission of pathogens

Answer 1

Through contact, transfer of bodily fluids, droplets, ingestion, airborne transmission, vectors

Question 2

Non-specific defences

Answer 2

Works against all pathogens, and consists of external defences, leucocytes and macrophages, the inflammatory response

Question 3

Steps of the inflammatory response

Answer 3

1. Mast cells release histamine, heparin into extracellular fluid
2. Histamine increases blood flow in the area by increasing the permeability of capillaries; causes heat and swelling
3. Heparin prevents blood clotting
4. Chemicals released by mast cells attract phagocytes
5. Abnormal conditions stimulate pain receptors

Question 4

Function of histomine

Answer 4

increases capillary permeability, hence blood flow in area; causes heat and swelling

Question 5

Function of heparin

Answer 5

Prevents blood clotting

Question 6

Fever

Answer 6

High body temperature inhibits the growth of bacteria and viruses, increases the rate of chemical reactions. Can be harmful if exceeds 44 C

Question 7

External Defences

Answer 7

consists of all external barriers; skin, mucous membranes, sebaceous secretions

Question 8

Protective Reflexes

Answer 8

Protect the body from injury and infection - sneezing, coughing, vomiting

Question 9

Lymphatic Systems

Answer 9

collects excess extracellular fluid and returns it to the circulatory system

Question 10

Lymph node

Answer 10

contains lymphoid tissue that traps large particles such as bacteria

Question 11

Specific Immunity

Answer 11

Directed towards a specific pathogen

Question 12

B cells

Answer 12

Mature in the bones, found in the blood and lymphoid tissue; involves in humoral and cell-mediated immunity

Question 13

T cells

Answer 13

Matures in the thymus, found in lymph nodesl involved in cell-mediated immunity

Question 14

Antigens

Answer 14

Any substance capable of causing a specific immune response

Question 15

Self antigens

Answer 15

recognised by the immune system as belonging to the body - don’t cause an immune response

Question 16

Non-self antigens

Answer 16

recognised as not belonging to the body - triggers an immune response

Question 17

Humoral immunity

Answer 17

1. Antigen sensitises B cell
2. B cell enlarges, clones
   Either form plasma cells or memory cells
3. Memory cells respond to re-exposure of antigen (secondary response), while plasma cells/antibodies attack antigens

Question 18

Antibodies

Answer 18

Combine with bacterial/ viral toxins/ enzymes and inhibit them
Bind to viruses to prevent cell entry
Coat bacteria – easier phagocytosis
Cause agglutination of foreign particles
Create insoluble substances – easier phagocytosis

Question 19

Cell mediated immunity

Answer 19

1. B cell/macrophage encounters antigen and presents it to nearest lymph node
2. T cell becomes sensitised
3. T cell enlarges and clones into 3 types of T cells or memory cell

Question 20

Killer T Cells

Answer 20

migrate and attach to invading cells

Question 21

Helper T Cells

Answer 21

cause more lymphocytes to become more sensitized, attracts macrophages and intensifies phagocytosis

Question 22

Suppressor T Cells

Answer 22

Releases substances that inhibit B and T cell activity

Question 23

Types of Immunity

Answer 23

Natural, artificial, passive, natural

Question 24

Natural Immunity

Answer 24

occurs without human intervention

Question 25

Artificial immunity

Answer 25

results through intervention

Question 26

Passive immunity

Answer 26

production of antibodies elsewhere

Question 27

Active immunity

Answer 27

the body produces its own antigens after exposure to an antigen

Question 28

Immunisation

Answer 28

The artificial introduction of antigens into the body to develop antigens

Question 29

Vaccine

Answer 29

The antigen preparation used in the immunisation

Question 30

Antibiotics

Answer 30

Works specifically on bacterial infections, not effective against viruses

Question 31

Bactericidal

Answer 31

Kills bacteria by changing/damaging the structure of their cell wall

Question 32

Bacteriostatic

Answer 32

Blocks protein synthesis to stop reproduction

Question 33

Multiple drug resistant bacteria

Answer 33

Develops through overuse of antibacterial, allowing bacteria resistant to the antibacterial to reproduce

Question 34

Antivirals

Answer 34

specifically for treating viral infections; inhibits the development of the virus

Question 35

Differences between antibacterial and antivirals

Answer 35

Antibacterials are designed to specifically treat bacterial infections, hence cannot treat viral infections. Antibacterials are designed to kill/damage bacteria, antivirals prevent/slow cell entry and reproduction