Immunity

Question 1

Define the term ‘antigen’

3 points

Answer 1

An antigen is any substance that the immune system can recognise an d respond to Antigen are not always infections agents. Most antigens are proteins

Question 2

Define immunological Tolerance

Answer 2

A state of immunological non-reactivity to an antigen.
This is important because some antigens (self-antigens, environmental antigen and commensal organism antigens) are not harmful.

Question 3

Failure in immunological tolerance results in?

Give 2 examples

Answer 3

1. Allergic reactions

2. Autoimmunity

Question 4

How does allergy occur?

Answer 4

Allergy occurs as a result of failure in immunological tolerance. The immune system produces a response against harmless environmental antigens such a pollen.

Question 5

How does Auto-immune disease occur?

Answer 5

The immune system attacks the body’s own tissues because it does not recognise it posses a self-antigen.
E.g rheumatoid arthritis - immune system attacks the joints.

Question 6

List 2 forms of immunodeficiency

Answer 6

1. Acquired immunodeficiency
2. Genetic immunodeficiency
   (make a card that explains it with examples)*

Question 7

Define the term ‘self antigen’

Answer 7

These are antigens which belongs to our own body. E.g RBC have antigens on them. Group types named after which antigen they present. E.g Group A has antigen A.

Question 8

What is meant by the term ‘primary immune response’?

Answer 8

The response that is generated the first time an antigen is met. In infancy, PR is the norm. In adults, mostly SR except adult travels to a new part of the world and meets a new pathogen.

Question 9

What is meant by the term ‘antigen specific’?

Answer 9

An immune response is DIRECTED against a particular antigen and not against antigens in general.