What does the term 'memory' of the immune system mean?
When the body encounters a pathogen for the first time, it mounts an immune response by generating antibodies. This response is of low intensity. Subsequent encounter with the same pathogen elicits a highly intensified secondary response.
This is ascribed to the fact that our body appears to have memory of the first encounter. This type of secondary immune response is elicited by memory T-cells, B-cell which keep ready to mount a rapid and vigorous attack as soon as the same pathagen infects the body again.
If a patient is advised anti restroviral therapy, which infection is he suffering from?
Name the causative organism.
The patient is suffering from AIDS. The causative agent is HIV virus, a member of 'retrovirus group'.
Differentiate between active immunity and passive immunity.
Differentiate between active immunity and passive immunity
| Active Immunity | Passive Immunity |
|---|---|
| It is developed due to contact with pathogen or its antigen. | It is developed when ready-made antibodies are injected into the body. |
| It has no side effects . | It may cause a reaction. |
| It is slow but long lasting. | It is fast but lasts only for few days. |
| It takes time to develop its response. | It is used when the immune response has to be faster. |
| e.g., vaccination for polio, etc | e.g., administration of tetanus antitoxins, etc. |
Differentiate between bening tumour and malignant immunity
| Benign Tumour | Malignant Tumour |
|---|---|
| It is a non-cancerous tumour. | It is a cancerous tumour. |
| Benign tumour does not show metastasis and is non-invasive. | It shows metastasis and thus invades other body parts. |
| It stops growth after reaching a certain size. | Malignant tumour shows indefinite growth. |
| Limited adherence occurs amongst cells of benign tumour. | There is no adherence amongst cells. They tend to slip past one another. |
| It is less fatal to the body. | It is more fatal to the body. |
Do you consider passive smoking is more dangerous than active smoking? Why?
Passive smoking can be equally dangerous because it exposes the persons to the same harmful effect of smoke.
Passive or second hand smoking means being in the same room or place, where some one is smoking and getting exposed to smoke in the surrounding air.
Once inhaled, the smoke can trigger release of mucus in the bronchioles that blocks the airways. This induces coughing. But prolonged exposures can lead to bronchitis emphysema, respiratory tract infections and eventually lung cancer.