Practise phagocytosis, antigen-specific lymphocyte responses, antibody action and vaccination while comparing active, passive, primary and secondary immunity.
Some pathogens can enter the human body through the gas exchange system.
The infectious lung disease, pneumonia, can be caused by Streptococcus pneumoniae.
Most healthy people inhaling air containing these bacteria do not become ill because of the action of the alveolar macrophages.
Outline the mode of action of an alveolar macrophage in response to the presence of S. pneumoniae.
You may use diagrams with notes to help your answer.
Irritants in tobacco smoke can contribute to emphysema, one of the chronic obstructive pulmonary disorders (COPD). In emphysema, the alveoli lose their ability to recoil on expiration and can burst.
Fig. 4.1 is a transmission electron micrograph of the bacterium that causes cholera, Vibrio cholerae.
The flagellum shown in Fig. 4.1 allows movement of the bacterium within the gut and may also function to help it to bind to an intestinal epithelial cell. The organism does not enter the cell but the toxin it releases can enter and cause damage. Large quantities of water, chloride ions and sodium ions are lost from the cell.
Fig. 4.1
People with symptoms of cholera have severe watery diarrhoea and as a result can become very dehydrated.
Most people who have recovered from cholera rarely become ill again from the disease. In these people, antibodies have been identified that will bind either to the cholera toxin, or to the bacterial flagellum, or to the main bacterial cell.
Explain why the antibodies are different, each one specific to its target.
Evidence suggests that newborn babies of mothers who have had cholera have immunity to the disease.
State precisely the type of immunity these babies are likely to have.
Rheumatoid arthritis (RA) is a disease of the joints in the human body.
RA is classed as an auto-immune disease where the immune system treats some self antigens as non-self.
Explain what is meant by the term non-self antigens.
The symptoms of RA include inflammation of the joints which causes pain and difficulty in movement of the joint.
The inflammation is triggered by a chemical known as TNF- , produced by macrophages.
One approach to the treatment of RA is by the use of monoclonal antibody against TNF- .
Fig. 3.1 is a diagram of an antibody molecule.
Fig. 3.1
Name the parts of the antibody molecule labelled P, Q and R.
P
Q
R
Outline how monoclonal antibody against TNF- is produced.
Suggest how monoclonal antibody against TNF- can reduce the symptoms of RA.