Second line of defence

Neutrophils

• secret complement proteins

• migrate to the site of infection and engulf invading pathogens

• increase the diameter of blood vessels to make them more permeable

• release histamine following the binding of the antigen to receptors on the neutrophil's surface

Some human cells produce proteins called cytokines.

A major function of cytokines is

• signalling immune cells in inflammatory responses

• stimulating B cells to directly attack virally infected cells

• diffusing across a synaptic gap to stimulate the adjacent cell

• communicating very rapidly with a cell that is distance from the cytokine-produce cell

The diagram shows an immune cell responding to a substance. This process occurs during certain types of allergic reactions.

What type of immune cell is featured in the diagram?

• mast cell

• neutrophil

• macrophage

• dendritic cell

In the degranulation process shown in the diagram, an intracellular substance (Z) leaves the cell.

Which intracellular substance is released?

• caspase

• histamine

• pheromone

• neutrotransmitter

The diagram shows the process of phagocytosis. This process is vital for immunity against extracellular infections.

What is happening at position 3?

• Enzymes that break down the microorganism are released into the vesicle.

• Antibodies are added to the vesicle to kill the microorganism.

• The cell is sampling the vesicle for antigen presentation.

• Intracellular microbes are attacking the microorganism.

Lupus is a condition that results in the increased secretion of antibodies that attach themselves to healthy cells in a patient's body. The accumulation of these antibodies causes inflammation, joint pain, rash, fatigue and fever.

Lupus is an example of

• an allergic reaction

• an autoimmune disease

• an immune deficiency disease

• a complement protein response

Which of the following (in the table) matches a cell correctly with its role in an immune response?

• A

• B

• C

• D

The inflammatory response is a defence mechanism that evolved in higher organisms to protect them from infection and injury.

This response

• includes phagocyte migration to the site of the injury

• is part of the adaptive immune system

• is specific to the type of foreign body

• involves the production of lymphocytes

A girl is carrying a piece of wood. A small piece breaks off and becomes embedded in her finger. The next day, she notices an inflammatory response occurring in her finger.

In the region around the small piece of wood embedded in her finger

• mast cells would release antibodies

• the skin tissue would become pale and cold

• the capillaries would become more permeable

• red blood cells would leave the blood vessels and engulf foreign material

An example of a non-specific response by the immune system is

• phagocytes engulfing non-self material

• cytotoxic T cells releasing chemicals into infected cells

• production of memory T cells

• cloning of B cells to produce plasma cells