Secondary Non Specific Defences

Question 1

Secondary non specific defences

Answer 1

Part of the immune response. Used to combat pathogens once entered body.

Question 2

Function of an Opsonin

Answer 2

Antigens are specific to an organism.
Opsonins are protein molecules that attach to the antigen on the surface of a pathogen. They enhance the ability of phagocytic cells to bind and engulf the pathogen.

Question 3

The first line of secondary defences is phagocytosis. The most common phagocyte is a neutrophil. How are they identified?

Answer 3

Manufactured in the bone marrow.
Multi-loves nucleus.
Neutrophils engulf and digest pathogens.

Question 4

Process of phagocytosis:

Answer 4

1) neutrophil binds to opsonin attached to the antigen of a pathogen.
2) the pathogen is engulfed by endocytosis. Forming a phagosome.
3) lysosomes fuse to the phagosome and release lytic enzymes.
4) after digestion the harmless products can be absorbed into the cell.

Question 5

What is the role of a macrophage?

Answer 5

Macrophages play a role in initiating the specific immune response. When a macrophage engulfs a pathogen, it does not fully digest it. The antigen from the surface of the pathogen is saved and moved to the surface of the cell.

It becomes an antigen presenting cell. So cells of the immune response can recognise the antigen.