Immunity

Question 1

Natural passive immunity

Answer 1

The passive transfer of antibodies from mother to foetus through the placenta/breast feeding.

Question 2

Artificial passive immunity

Answer 2

Involves an individual receiving (usually antiserum) of specific antibodies produced by another organism.

Question 3

Natural active immunity

Answer 3

Develops from the adaptive immune response to a natural infection, and the immunological memory that results.

Question 4

Artificial active immunity

Answer 4

Results from the administration of antigens to induce an adaptive immune response.

Question 5

Vaccination

Answer 5

The technique of artificially inducing an adaptive immune response by administering a weakened, altered or killed version microorganisms or inactivated forms of toxins/antigens.

Question 6

Herd immunity

Answer 6

Phenomenon in which vaccination of a large proportion of a population provides protection from a pathogen to non-immune/ non-vaccinated individuals.

Question 7

Autoimmune disease

Answer 7

Disease in which there is failure of tolerance and an adaptive immune response is directed against self antigens, causing t lymphocytes to attack tissues directly and b lymphocytes to produce antibodies against self-antigens.

Question 8

Immunodeficiency

Answer 8

An inadequate response by the immune system to the presence of antigens. Acquired (Aids) or congenital ( Di George syndrome).

Question 9

Allergic reactions

Answer 9

The rapid and vigorous overreaction of the immune system to antigens called allergens. Involves the production of IgE by b lymphocytes and the release of histamines by mast cells.

Question 10

Pollen allergy steps

Answer 10

1. Initial exposure to pollen antigen triggers plasma cells to produce IgE molecules specific to the antigen.
2. Tail end of IgE binds to receptors on mast cells.
3. Subsequent exposure to same allergen, cause antigen to bind to two IgE molecules on the mast cell.
4. This binding triggers a signal cascade that causes the release of histamine.
5. Histamine binds to receptors on various cells of the body, which produces classic reaction of an allergic reaction.

Question 11

Multiple sclerosis

Answer 11

Nerves of the myelin sheaths insulating them are lost resulting in nerve damage/ impairment.

Question 12

HIV

Answer 12

A retrovirus (rna virus) that makes a DNA copy of its genetic information by reverse transcription. Results in production of many copies of the virus. When the number of t lymphocytes become low (due to them being used to try kill the fast mutating virus) that adaptive immune system is impaired and AIDS has developed.

Question 13

Tumour

Answer 13

Forms when the number of abnormal cells has increased significantly forming a clump of cells. Cancer tumour cells are said to be malignant.

Question 14

Immunotherapy

Answer 14

Any treatment that harnesses the immune system of the patient to fight diseases.

Question 15

Cancer vaccines

Answer 15

Stimulate the immune system to attack cancer cells.

Question 16

Monoclonal antibody therapy

Answer 16

Using mAbs (clone antibodies specific to the same antigen) to treat cancer by targeting specific antigens on cancer cells.